In this Space Shuttle STS-102 mission image, the Payload Equipment Restraint System H-Strap is shown at the left side of the U.S. Laboratory hatch and behind Astronaut James D. Weatherbee, mission specialist. PERS is an integrated modular system of components designed to assist the crew of the International Space Station (ISS) in restraining and carrying necessary payload equipment and tools in a microgravity environment. The Operations Development Group, Flight Projects Directorate at the Marshall Space Flight Center (MSFC), while providing operation support to the ISS Materials Science Research Facility (MSRF), recognized the need for an on-orbit restraint system to facilitate control of lose objects, payloads, and tools. The PERS is the offspring of that need and it helps the ISS crew manage tools and rack components that would otherwise float away in the near-zero gravity environment aboard the Space Station. The system combines Kevlar straps, mesh pockets, Velcro and a variety of cornecting devices into a portable, adjustable system. The system includes the Single Strap, the H-Strap, the Belly Pack, the Laptop Restraint Belt, and the Tool Page Case. The Single Strap and the H-Strap were flown on this mission. The PERS concept was developed by industrial design students at Auburn University and the MSFC Flight Projects Directorate.

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, STS-134 Pilot Greg H. Johnson checks the fit of his helmet in the Operations and Checkout Building at NASA's Kennedy Space Center in Florida. Next, Johnson and his crewmates will walk out to the waiting Astrovan. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members will ride to the pad in their silver Astrovan and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the White Room of Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-134 Pilot Greg H. Johnson prepares to board space shuttle Endeavour during the Terminal Countdown Demonstration Test (TCDT). Part of TCDT includes practicing the final hours of a real launch day when astronauts put on their launch-and-entry suits, ride to the pad in the Astrovan and strap into the shuttle. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann

CAPE CANAVERAL, Fla. -- STS-134 Pilot Greg H. Johnson gives a thumbs-up as he takes his seat aboard space shuttle Endeavour during the Terminal Countdown Demonstration Test (TCDT) on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Part of TCDT includes practicing the final hours of a real launch day when astronauts put on their launch-and-entry suits, ride to the pad in the Astrovan and strap into the shuttle. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, the STS-134 crew walks out of the Operations and Checkout Building to the waiting Astrovan at NASA's Kennedy Space Center in Florida. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members ride to Kennedy's Launch Pad 39A in the silver vehicle and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. From front, left to right, are STS-134 Pilot Greg H. Johnson, Commander Mark Kelly; second row; astronaut Roberto Vittori from the European Space Agency and Mission Specialist Mike Fincke; third row are Mission Specialists Greg Chamitoff and Andrew Feustel. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT, they will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the space station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, STS-134 Commander Pilot Greg H. Johnson checks the fit of his bright-orange, launch-and-entry suit in the Operations and Checkout Building at NASA's Kennedy Space Center in Florida. Next, Johnson and his crewmates will walk out to the waiting Astrovan. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members will ride to the pad in their silver Astrovan and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the White Room of Launch Pad 39A at NASA's Kennedy Space Center in Florida, the Closeout Crew helps STS-134 Pilot Greg H. Johnson put on the parachute for his launch-and-entry suit before he boards space shuttle Endeavour during the Terminal Countdown Demonstration Test (TCDT). Part of TCDT includes practicing the final hours of a real launch day when astronauts put on their launch-and-entry suits, ride to the pad in the Astrovan and strap into the shuttle. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kevin O'Connell

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, the STS-134 crew walks out of the Operations and Checkout Building to the waiting Astrovan at NASA's Kennedy Space Center in Florida. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members ride to Kennedy's Launch Pad 39A in the silver vehicle and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. From front, left to right, are STS-134 Pilot Greg H. Johnson, Commander Mark Kelly; second row; astronaut Roberto Vittori from the European Space Agency and Mission Specialist Mike Fincke; third row are Mission Specialists Greg Chamitoff and Andrew Feustel. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, the STS-134 crew walks out of the Operations and Checkout Building to the waiting Astrovan at NASA's Kennedy Space Center in Florida. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members ride to Kennedy's Launch Pad 39A in the silver vehicle and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. From right to left are, Commander Mark Kelly, Mission Specialist Mike Fincke, Pilot Greg H. Johnson, Roberto Vittori, European Space Agency astronaut, and Mission Specialists Andrew Feustel and Greg Chamitoff. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett

CAPE CANAVERAL, Fla. -- In the White Room of Launch Pad 39A at NASA's Kennedy Space Center in Florida, the Closeout Crew helps STS-134 Mission Specialist Greg Chamitoff put on the parachute for his launch-and-entry suit before he boards space shuttle Endeavour during the Terminal Countdown Demonstration Test (TCDT). Behind Chamitoff is Pilot Greg H. Johnson. Part of TCDT includes practicing the final hours of a real launch day when astronauts put on their launch-and-entry suits, ride to the pad in the Astrovan and strap into the shuttle. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kevin O'Connell

STS-95 Payload Specialist John H. Glenn Jr., senator from Ohio, straps into the seat of the T-38 jet aircraft that will carry him back to Houston. Mission Commander Curtis L. Brown, his pilot on the jet, looks on. The STS-95 successfully completed their Terminal Countdown Demonstration Test (TCDT) which included mission familiarization activities, emergency egress training, and a simulated main engine cutoff. Other crew members participating were Pilot Steven W. Lindsey, Mission Specialist Stephen K. Robinson, Payload Specialist Chiaki Mukai (M.D., Ph.D.), representing the National Space Development Agency of Japan (NASDA), Mission Specialist Pedro Duque of Spain, representing the European Space Agency (ESA), and Mission Specialist Scott E. Parazynski. The STS-95 mission, targeted for liftoff on Oct. 29, includes research payloads such as the Spartan solar-observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as the SPACEHAB single module with experiments on space flight and the aging process. Following the TCDT, the entire crew returned to Houston for final flight preparations

CAPE CANAVERAL, Fla. -- During a simulated launch countdown, the STS-134 crew pause for a photo opportunity before climbing onboard the Astrovan at NASA's Kennedy Space Center in Florida. As part of the Terminal Countdown Demonstration Test (TCDT), the crew members ride to Kennedy's Launch Pad 39A in the silver vehicle and strap into space shuttle Endeavour to practice the steps that will be taken on launch day. From right to left are, Commander Mark Kelly, Pilot Greg H. Johnson , Mission Specialist Mike Fincke, Roberto Vittori, European Space Agency astronaut, and Mission Specialists Andrew Feustel and Greg Chamitoff. Endeavour's six crew members are targeted to launch April 19 at 7:48 p.m. EDT. They will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station. This will be the final spaceflight for Endeavour. For more information visit, www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Kim Shiflett