CAPE CANAVERAL, Fla. - STS-126 Mission Specialist Shane Kimbrough arrives at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida aboard a T-38 jet for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Mission Specialist Steve Bowen, left, is greeted by Shuttle Launch Director Mike Linebach following his arrival at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Mission Specialist Heidemarie Stefanyshyn-Piper arrives at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida aboard a T-38 jet for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Mission Specialist Sandra Magnus arrives at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida aboard a T-38 jet for Terminal Countdown Demonstration Test, or TCDT, activities. Magnus will remain on the International Space Station as a flight engineer and science officer for Expedition 18. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Mission Specialist Donald Pettit arrives at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Crew members for space shuttle Endeavour's STS-126 mission pose for a group portrait at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida after arriving for Terminal Countdown Demonstration Test, or TCDT, activities. From left are Mission Specialists Shane Kimbrough and Steve Bowen, Pilot Eric Boe, Commander Chris Ferguson, and Mission Specialists Donald Pettit, Heidemarie Stefanyshyn-Piper and Sandra Magnus. Magnus will remain on the International Space Station as a flight engineer and science officer for Expedition 18. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - Crew members for space shuttle Endeavour's STS-126 mission speak to the media at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida after arriving for Terminal Countdown Demonstration Test, or TCDT, activities. From left are Mission Specialists Shane Kimbrough and Steve Bowen, Pilot Eric Boe, Commander Chris Ferguson, and Mission Specialists Donald Pettit, Heidemarie Stefanyshyn-Piper and Sandra Magnus. Magnus will remain on the International Space Station as a flight engineer and science officer for Expedition 18. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Pilot Eric Boe, left, and Mission Specialist Shane Kimbrough arrive at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Commander Chris Ferguson, left, is greeted by Shuttle Launch Director Mike Linebach following his arrival at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-126 Commander Chris Ferguson speaks to the media at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida after arriving for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, Endeavour's astronauts and launch teams will participate in a simulated countdown, practice emergency exit procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. On this 27th mission to the International Space Station, Endeavour will carry the Lightweight Multi-Purpose Experiment Support Structure Carrier and the Multi-Purpose Logistics Module Leonardo that will hold supplies and equipment, including additional crew quarters, additional exercise equipment, spare hardware and equipment for the regenerative life support system. Endeavour is targeted to launch at 7:55 p.m. EST on Nov. 14. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-88 Mission Specialists Sergei Krikalev and James H. Newman practice emergency egress procedures in a slidewire basket at Launch Pad 39A as part of Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for launch. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module

STS-82 Mission Specialist Steven L. Smith adjusts the glove of his launch and entry space suit during a practice countdown at KSC. Smith and the other six STS-82 crew members are at KSC to participate in the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. STS-82 will be the second Hubble Space Telescope servicing mission. Liftoff is targeted for Feb. 11

KENNEDY SPACE CENTER, Fla. -- STS-118 Commander Scott Kelly practices driving an M-113 armored personnel carrier with fellow crew members Tracy Caldwell, Alvin Drew and Dave Williams, all mission specialists, as passengers. They are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

KENNEDY SPACE CENTER, Fla. -- STS-118 Pilot Charlie Hobaugh practices driving an M-113 armored personnel carrier with passenger (at left) Tracy Caldwell, mission specialist. They and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Clayton Anderson, at right, prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Regina Mitchell-Ryall

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Stephanie Wilson awaits her turn to enter space shuttle Discovery. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Stephanie Wilson prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Regina Mitchell-Ryall

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Rick Mastracchio prepares to enter space shuttle Discovery from the pad's White Room. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Commander Alan Poindexter, at right in the orange suit, prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Regina Mitchell-Ryall

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Clayton Anderson prepares to enter space shuttle Discovery from the pad's White Room. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Rick Mastracchio prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Regina Mitchell-Ryall

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Naoko Yamazaki of the Japan Aerospace Exploration Agency awaits her turn to enter space shuttle Discovery. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Commander Alan Poindexter, in the orange suit, prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonardo, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo courtesy of Scott Andrews

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Pilot James P. Dutton Jr., at left, prepares to enter space shuttle Discovery from the pad's White Room. The members of space shuttle Discovery's STS-131 crew, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Regina Mitchell-Ryall

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Pilot James P. Dutton Jr. prepares to enter space shuttle Discovery from the pad's White Room. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - At Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Dorothy Metcalf-Lindenburger awaits her turn to enter space shuttle Discovery. The crew members of Discovery's STS-131 mission, dressed in their launch-and-entry suits, are participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency exit systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Dimitri Gerondidakis

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Pilot James P. Dutton Jr. suits up for his first practice countdown. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Rick Mastracchio suits up for his third practice countdown. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. –At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, a Shuttle Training Aircraft, or STA, approaches the runway during landing practice. STS-128 Commander Rick Sturckow and Pilot Kevin Ford are using the STAs to practice shuttle landings. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At NASA's Kennedy Space Center in Florida, STS-128 Mission Specialist Jose Hernandez practices getting out of a slidewire basket that can be used for emergency exit from Launch Pad 39A. Still in the basket, at left, is Mission Specialist Nicole Stott. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Karen Nyberg is ready to begin driving practice in the M113 armored personnel carrier, part of emergency training. Behind her is Pilot Ken Ham. She and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Mike Fossum stands ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At the slidewire basket landing area near Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Julie Payette practices getting out of a basket, which are used for emergency exits from the pad. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is targeted for June 13. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Ron Garan is pleased with his driving practice in the M113 armored personnel carrier, part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Akihiko Hoshide takes his place in the M113 armored personnel carrier, to practice driving as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At the slidewire basket landing area near Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-127 crew members practice getting out of a basket. The baskets are used for emergency exits from the pad. Inside the basket are Mission Specialists Julie Payette and Tim Kopra. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is targeted for June 13. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Pilot Ken Ham stands ready to practice driving the M113 armored personnel carrier as part of emergency training. Behind him is Mission Specialist Karen Nyberg. Ham and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Commander Mark Kelly is ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Mission Specialist Greg Chamitoff stands ready to practice driving the M113 armored personnel carrier as part of emergency training. He and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Mission Specialists Michael Barratt and Nicole Stott pause for a photo after arrival in T-38 training jets to the Shuttle Landing Facility. The STS-133 crew is at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Mission Specialist Steven Swanson is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Rick Mastracchio verifies that his helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Commander Steve Lindsey talks with Shuttle Launch Director Mike Leinbach at the Shuttle Landing Facility. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Dorothy Metcalf-Lindenburger verifies that her helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-133 Mission Specialist Tim Kopra arrives in a T-38 jet to the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

STS-106 Mission Specialist Boris V. Morukov, eager to start Terminal Countdown Demonstration Test (TCDT)activities, arrives at the KSC Shuttle Landing Facility aboard a T-38 jet aircraft. As part of TCDT, he and the rest of the crew will practice emergency egress from the Fixed Service Structure and driving the M113 armored carrier, plus take part in a dress rehearsal for launch with a simulated countdown. STS-106 is scheduled to launch Sept. 8, 2000, at 8:31 a.m. EDT from Launch Pad 39B. On the 11-day mission, the seven-member crew will perform support tasks on orbit, transfer supplies and prepare the living quarters in the newly arrived Zvezda Service Module. The first long-duration crew, dubbed “Expedition One,” is due to arrive at the Station in late fall

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Pilot Eric Boe is greeted by Shuttle Launch Director Mike Leinbach at the Shuttle Landing Facility. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Pilot Lee Archambault is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Stephanie Wilson verifies that her helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-133 Commander Steve Lindsey and Mission Specialist Tim Kopra arrive in a T-38 jet at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- A NASA helicopter monitors the arrival of the STS-133 crew as they arrive in T-38 jets at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the STS-133 crew poses for a group portrait following their arrival for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT). From left are Mission Specialists Nicole Stott, Michael Barratt, Tim Kopra, Alvin Drew; Pilot Eric Boe and Commander Steve Lindsey. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Barbara R. Morgan practices driving an M-113 armored personnel carrier as part of emergency exit training. Seen in the back, at left, are Commander Scott Kelly and Mission Specialists Tracy Caldwell and Alvin Drew. Morgan joined NASA's Teacher in Space program in 1985 and was selected as an astronaut in 1998. She and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

STS-106 Mission Specialist Boris V. Morukov, eager to start Terminal Countdown Demonstration Test (TCDT)activities, arrives at the KSC Shuttle Landing Facility aboard a T-38 jet aircraft. As part of TCDT, he and the rest of the crew will practice emergency egress from the Fixed Service Structure and driving the M113 armored carrier, plus take part in a dress rehearsal for launch with a simulated countdown. STS-106 is scheduled to launch Sept. 8, 2000, at 8:31 a.m. EDT from Launch Pad 39B. On the 11-day mission, the seven-member crew will perform support tasks on orbit, transfer supplies and prepare the living quarters in the newly arrived Zvezda Service Module. The first long-duration crew, dubbed “Expedition One,” is due to arrive at the Station in late fall

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Dorothy Metcalf-Lindenburger seems pleased with the fit of her spacesuit. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Mission Specialist Tim Kopra speaks to the media gathered for the crew’s arrival at the Shuttle Landing Facility. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Mission Specialist James Reilly is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Pilot James P. Dutton Jr. verifies that his helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Mission Specialist Patrick Forrester is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the STS-133 crew poses for a group portrait following their arrival for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT). From left are Mission Specialists Nicole Stott, Michael Barratt, Tim Kopra, Alvin Drew; Pilot Eric Boe and Commander Steve Lindsey. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Jack Pfaller

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Mission Specialist Danny Olivas is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Alvin Drew practices driving an M-113 armored personnel carrier, with (at right) Mission Specialists Barbara R. Morgan and Dave Williams as passengers. Morgan joined NASA's Teacher in Space program in 1985 and was selected as an astronaut in 1998. Williams represents the Canadian Space Agency. They and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Clayton Anderson adjusts his helmet. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, Shuttle Launch Director Mike Leinbach greets STS-133 Mission Specialist Alvin Drew at the Shuttle Landing Facility as Pilot Eric Boe looks on. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Commander Rick Sturckow signals that he is ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Pilot Eric Boe (left); Mission Specialists Nicole Stott, Alvin Drew and Michael Barratt greet each other after their arrival at the Shuttle Landing Facility. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- STS-124 Commander Mark Kelly sits in the cockpit of NASA's Shuttle Training Aircraft, or STA, preparing to practice space shuttle landings. The STA is a Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter's cockpit, motion and visual cues, and handling qualities. In flight, the STA duplicates the orbiter's atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. The crew for space shuttle Discovery's STS-124 mission is at Kennedy for a full launch dress rehearsal, known as the terminal countdown demonstration test, or TCDT. Providing astronauts and ground crews with an opportunity to participate in various simulated countdown activities, TCDT includes equipment familiarization and emergency training. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Stephanie Wilson seems pleased with the fit of her spacesuit. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Rick Mastracchio practices driving an M-113 armored personnel carrier as part of emergency exit training. The astronauts seen behind him are Mission Specialists Alvin Drew, Barbara R. Morgan, Dave Williams (standing) and Tracy Caldwell. Morgan joined NASA's Teacher in Space program in 1985 and was selected as an astronaut in 1998. Williams represents the Canadian Space Agency. The crew is at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Tracy Caldwell practices driving an M-113 armored personnel carrier as part of emergency exit training. Seen in the back are Mission Specialist Alvin Drew, Pilot Charlie Hobaugh and educator astronaut and Mission Specialist Barbara R. Morgan. They and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Commander Alan Poindexter appears enthusiastic about the opportunity to board Discovery. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Commander Alan Poindexter verifies that his helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Rick Mastracchio gets ready to practice driving an M-113 armored personnel carrier as part of emergency exit training. Behind him, at right, is Mission Specialist Tracy Caldwell. They and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

CAPE CANAVERAL, Fla. -- STS-133 crew members begin to arrive at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida in T-38 training jet. The crew is at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Jack Pfaller

CAPE CANAVERAL, Fla. - In the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, STS-131 Mission Specialist Clayton Anderson verifies that his helmet is functioning properly. The members of space shuttle Discovery's STS-131 crew put on their launch-and-entry suits before heading to the Astrovan for the ride to Launch Pad 39A. The crew is participating in the Terminal Countdown Demonstration Test, or TCDT, a dress rehearsal for launch. TCDT includes training on the emergency egress systems at the launch pad, driving practice of the M-113 armored personnel carrier and a simulated launch countdown. The crew will deliver the multi-purpose logistics module Leonard, filled with resupply stowage platforms and science racks, to the International Space Station. STS-131, targeted for launch on April 5, will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. For information on the STS-131 mission and crew, visit http:__www.nasa.gov_mission_pages_shuttle_shuttlemissions_sts131_index.htm. Photo credit: NASA_Kim Shiflett

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Barbara R. Morgan is ready to practice driving an M-113 armored personnel carrier as part of emergency exit training. Behind her at the rear are Mission Specialists (left) Tracy Caldwell and Dave Williams. Morgan joined NASA's Teacher in Space program in 1985 and was selected as an astronaut in 1998. She and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

KENNEDY SPACE CENTER, Fla. -- STS-118 Commander Scott Kelly practices driving an M-113 armored personnel carrier, as part of emergency exit training, with fellow crew members aboard. Behind Kelly is Mission Specialist Barbara R. Morgan. The crew is at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

KENNEDY SPACE CENTER, Fla. -- STS-118 Mission Specialist Dave Williams, who represents the Canadian Space Agency, gets ready to practice driving an M-113 armored personnel carrier as part of emergency exit training. Behind him is Mission Specialist Barbara R. Morgan. They and other crew members are at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton

KENNEDY SPACE CENTER, FLA. -- Members of space shuttle Atlantis' STS-122 crew practice emergency exit procedures in a slidewire basket at Launch Pad 39A following a simulated launch countdown. The exercise is part of terminal countdown demonstration test, or TCDT, activities at NASA's Kennedy Space Center. The TCDT is a dress rehearsal for launch and also provides astronauts and ground crews with equipment familiarization and emergency egress training. On mission STS-122, Atlantis will deliver the Columbus module to the International Space Station. The European Space Agency's largest single contribution to the station, Columbus is a multifunctional, pressurized laboratory that will be permanently attached to U.S. Node 2, called Harmony. The laboratory will expand the research facilities aboard the station, providing crew members and scientists from around the world the ability to conduct a variety of experiments in the physical, materials and life sciences. Atlantis' launch is targeted for Dec. 6. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- Members of space shuttle Atlantis' STS-122 crew practice emergency exit procedures in a slidewire basket at Launch Pad 39A following a simulated launch countdown. The exercise is part of terminal countdown demonstration test, or TCDT, activities at NASA's Kennedy Space Center. The TCDT is a dress rehearsal for launch and also provides astronauts and ground crews with equipment familiarization and emergency egress training. On mission STS-122, Atlantis will deliver the Columbus module to the International Space Station. The European Space Agency's largest single contribution to the station, Columbus is a multifunctional, pressurized laboratory that will be permanently attached to U.S. Node 2, called Harmony. The laboratory will expand the research facilities aboard the station, providing crew members and scientists from around the world the ability to conduct a variety of experiments in the physical, materials and life sciences. Atlantis' launch is targeted for Dec. 6. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. -- At Launch Complex 39, STS-117 Mission Specialist Patrick Forrester (right) waits his turn to practice driving an M-113 armored personnel carrier as fellow crew members look on. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, STS-133 Mission Specialist Michael Barratt speaks to the media gathered for the crew’s arrival at the Shuttle Landing Facility. The STS-133 crew members are at Kennedy for a practice launch dress rehearsal called the Terminal Countdown Demonstration Test (TCDT) in preparation for their upcoming mission. TCDT provides each shuttle crew and launch team with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. Space shuttle Discovery and its STS-133 crew will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the International Space Station. Launch is targeted for Nov. 1 at 4:40 p.m. For more information on the STS-133 mission, visit www.nasa.gov/shuttle. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – STS-127 Pilot Doug Hurley smiles after practicing driving the M-113 armored personnel carrier. The crew members of space shuttle Endeavour's STS-127 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes the emergency egress training and equipment familiarization. The STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex. Endeavour's launch is targeted for June 13. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – STS-127 Commander Mark Polansky smiles after practicing driving the M-113 armored personnel carrier. The crew members of space shuttle Endeavour's STS-127 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes the emergency egress training and equipment familiarization. The STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex. Endeavour's launch is targeted for June 13. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. –At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, one of the two Shuttle Training Aircraft, or STAs, waits to taxi to the runway. STS-128 Commander Rick Sturckow and Pilot Kevin Ford are using the STAs to practice shuttle landings. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. –At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-128 Pilot Kevin Ford settles in the cockpit of the Shuttle Training Aircraft, or STA, to practice shuttle landings. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-128 Commander Rick Sturckow heads up the stairs to the cockpit of the Shuttle Training Aircraft, or STA, to practice shuttle landings. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-128 Commander Rick Sturckow (left) and Pilot Kevin Ford are ready to begin practicing shuttle landings in the Shuttle Training Aircraft, or STA. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Commander Scott Altman is ready to practice driving the M-113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Megan McArthur practices driving the M-113 armored personnel carrier. Other crew members are behind her. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Pilot Gregory C. Johnson practices driving the M-113 armored personnel carrier. Behind him are other crew members. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist John Grunsfeld is ready to practice driving the M-113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Pilot Gregory C. Johnson is ready to practice driving the M-113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - An STS-125 crew member affixes a mission patch to the inside of the M-113 armored personnel carrier the crew practiced driving.The crew members of space shuttle Atlantis' STS-125 mission each practiced driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Mike Massimino is ready to practice driving the M-113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Michael Good practices driving the M-113 armored personnel carrier. Other crew members are behind him. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Andrew Feustel is ready to practice driving the M=113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. – At the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida, STS-128 Commander Rick Sturckow is pleased with the shuttle landing practice he completed in the Shuttle Training Aircraft, or STA. The practice is in preparation for launch of space shuttle Discovery's STS-128 mission in late August to the International Space Station. The STA is a Grumman American Aviation-built Gulfstream II jet that was modified to simulate a shuttle’s cockpit, motion and visual cues, and handling qualities. The STS-128 crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes emergency exit training and equipment familiarization, as well as a simulated launch countdown. Discovery will deliver 33,000 pounds of equipment to the station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and the COLBERT treadmill. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Mike Massimino practices driving the M-113 armored personnel carrier. Behind him are other crew members. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. - STS-125 Mission Specialist Michael Good is ready to practice driving the M-113 armored personnel carrier. The crew members of space shuttle Atlantis' STS-125 mission will each practice driving the M-113 in turn as part of their training on emergency egress procedures. An M-113 will be available to transport the crew to safety in the event of a contingency on the pad before their launch. The crew is at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test, or TCDT. It provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. The STS-125 mission aboard space shuttle Atlantis to service NASA’s Hubble Space Telescope is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett