Space Shuttle mission STS-61 onboard view taken by a fish-eyed camera lens showing astronauts Story Musgrave and Jeffrey Hoffman's Extra Vehicular Activity (EVA) to repair the Hubble Space Telescope (HST).

Cape St. Mary

The Space Shuttle Endeavour cuts a bright swath through the dark sky as it blazes a trail toward the Russian Space Station Mir. Endeavour lifted off successfully at its scheduled time of 9:48:15 p.m. EST on Jan. 22 from Pad 39A. STS-89 is the eighth docking with the Russian Space Station Mir, the first Mir docking for Endeavour (all previous dockings were made by Atlantis), and the first launch of 1998. After docking with Mir, Mission Specialist Andrew Thomas, Ph.D., will transfer to the space station, succeeding David Wolf, M.D., who will return to Earth aboard Endeavour. Dr. Thomas will live and work on Mir until June

Space Shuttle Endeavour STS-47 Spacelab J mission: Frog Embryology Experiment, Astronaut works with adult frog in 0 gravity using the glovebox to contain and protect the frog during procedures

View of Cape St. Mary from Cape Verde

Details of Layers in Victoria Crater Cape St. Vincent

STS-123 crew visit to Stennis Space Center; Bob Cabana

Guests use their laptop computers to "Tweet" and follow a NASA STS-127 crew presentation on Twitter at the NASA Tweetup event held at NASA Headquarters, September 24, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (NASA/Carla Cioffi)

Guests use their laptop computers to "Tweet" and follow a NASA STS-125 crew presentation on Twitter at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

James Branson of United Space Alliance, far left; Sandra Magnus, STS-135 mission specialist and Rex Walheim, STS-135 mission specialist, far right, are seen in the Astrovan as they ride to launch pad 39A to board space shuttle Atlantis on Friday, July 8, 2011, at the Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

Astronauts C.J. Sturckow (seated, left) and Pat Forrester (seated, right) sign autographs during their Oct. 7 visit to Stennis Space Center. The astronauts visited the rocket engine testing facility to thank Stennis employees for contributions to their recent STS-128 space shuttle mission. All three of the main engines used on the mission were tested at Stennis. Sturckow served as commander for the STS-128 flight; Forrester was a mission specialist. During a 14-day mission aboard space shuttle discovery, the STS-128 crew delivered equipment and supplies to the International Space Station, including science and storage racks, a freezer to store research samples, a new sleeping compartment and an exercise treadmill. The mission featured three spacewalks to replace experiments and install new equipment at the space station.

NASA Astronaut and STS-125 Mission Specialist Michael Good answers a question during a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

NASA Astronaut and STS-125 Mission Specialist John Grunsfeld answers a question during a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

NASA AStronaut and STS-125 Mission Specialist Andrew Feustel, right, answers a question during a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

NASA Astronaut and STS-125 Mission Pilot Scott Altman prepares to give a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

In the Space Station Processing Facility, the S3/S4 integrated truss segment is on display for the media. The starboard 3/4 truss segment will launch aboard Space Shuttle Atlantis on mission STS-117, targeted for March 15. The element will be added to the 11-segment integrated truss structure, the station's backbone. The integrated truss structure eventually will span more than 300 feet. The S3/S4 truss has two large solar arrays and will provide one-fourth of the total power generation for the completed station.

NASA astronaut Mike Massimino, left, and Sesame Street's Elmo speak at the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. Elmo asked the astronauts questions about living and working in space. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

Crowds are seen out the front window of the Astrovan carrying the STS-135 crew as it departs the NASA Kennedy Space Center, Operations and Checkout Building for launch pad 39A, on Friday, July 8, 2011 in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

NASA Twitter followers attending the STS-135 Tweetup are seen through the helmet of a NASA space suit, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

Cassie Barnes, Twitter handle @celticfeminist, tweets during the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

Susie Bodman, Twitter handle @sciwhat, tweets during the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

The exhaust plume from space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at the Kennedy Space Center on the STS-135 mission, Friday, July 8, 2011 in Cape Canaveral, Fla. Atlantis launched on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will deliver the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Dick Clark)

Tracy Thumm, left, and Justin Kugler both from the International Space Station Program Science Office at Johnson Space Center speak at the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

The STS-135 crew; Chris Ferguson, commander; Doug Hurley, pilot; Rex Walheim and Sandy Magnus, both mission specialists stop and pose for photographers before boarding the Astrovan that will take them to launch pad 39A for the launch of the space shuttle Atlantis on Friday, July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The press site at the NASA Kennedy Space Center is seen as the sun rises a few hours prior to the launch of the space shuttle Endeavour with the STS-134 crew, Monday, May 16, 2011, in Cape Canaveral, Fla. During the mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Photo Credit: (NASA/Bill Ingalls)

NASA Tweetup participants stand at the launch clock, Friday, July 8, 2011, prior to the launch of the space shuttle Atlantis (STS-135) at Kennedy Space Center in Cape Canaveral, Fla. Space shuttle Atlantis is set to launch on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will carry the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Paul E. Alers)

The STS-135 crew; Chris Ferguson, commander; Doug Hurley, pilot; Rex Walheim and Sandy Magnus, both mission specialists stop and pose for photographers before boarding the Astrovan that will take them to launch pad 39A for the launch of the space shuttle Atlantis on Friday, July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The exhaust plume from space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at the Kennedy Space Center on the STS-135 mission, Friday, July 8, 2011 in Cape Canaveral, Fla. Atlantis launched on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will deliver the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Dick Clark)

Lar DeSouza, Twitter handle @lartist, a cartoonist, sketches during the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

STS062-S-001 (October 1993) --- The crew patch depicts the world's first reusable spacecraft on its sixteenth flight. The space shuttle Columbia is in its entry-interface attitude as it prepares to return to Earth. The primary mission objectives of STS-62 include the United States Microgravity Payload (USMP-2) and the NASA Office of Aeronautics and Space Technology (OAST-2) payloads. These payloads represent a multifaceted array of space science and engineering experiments. The varied hues of the rainbow on the horizon connote the varied, but complementary, nature of all the payloads united on this mission. The upward-pointing vector shape of the patch is symbolic of America's reach for excellence in its in its unswerving pursuit to explore the frontiers of space. The brilliant sunrise just beyond Columbia suggests the promise that research in space holds for the hopes and dreams of future generations. The STS-62 insignia was designed by Mark Pestana. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

Stennis Space Center Director Patrick Scheuermann (r) welcomes members of the STS-135 space shuttle crew Aug. 11, marking a 'wheels stop' celebration of the 30-year Space Shuttle Program. The STS-135 mission was the last for the program. During the Aug. 11 visit, mission astronauts reported on their mission and spent time visiting with center employees.

Stennis Space Center Deputy Director Richard Gilbrech (center) presents commemorative plaques to STS-134 crew members Michael Fincke (l) and Gregory Chamitoff during their July 20 visit to the south Mississippi facility. During the visit, Fincke and Chamitoff spoke to Stennis employees about their STS-134 mission aboard shuttle Endeavour, the final flight to space for the NASA orbiter.

Stennis Space Center Director Patrick Scheuermann (r) welcomes members of the STS-135 space shuttle crew Aug. 11, marking a 'wheels stop' celebration of the 30-year Space Shuttle Program. The STS-135 mission was the last for the program. During the Aug. 11 visit, mission astronauts reported on their mission and spent time visiting with center employees.

This is a Space Shuttle mission STS-61 onboard view showing astronauts Story Musgrave and Jeffrey Hoffman preforming repairs to the Hubble Space Telescope (HST) during their Extra Vehicular Activity (EVA). Astronauts' work was made easier by the HST's many crew aids. Astronaut Musgrave makes use of one of the spacecraft's handholds. Launched on December 1, 1993, the Space Shuttle Orbiter Endeavor STS-061 mission was the 59th Shuttle flight.

The space shuttle Atlantis (STS-122) is serviced by support vehicles and crew at the Shuttle Landing Facility after the safe landing at 9:07a.m., Wednesday, Feb. 20, 2008 at Kennedy Space Center, Fla. Atlantis and the crew of STS-122 completed delivery of the European Space Agency’s (ESA) Columbus laboratory to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

S84-26327 (3 Feb. 1984) --- Beginning a busy year, NASA's space shuttle Challenger, attached to two solid rocket boosters and an external fuel tank which it will later jettison, blasts off from Pad A at Kennedy Space Center's Launch Complex 39 at 8:00 a.m. (EST), Feb. 3, 1984. Inside the STS 41-B spacecraft are astronauts Vance D. Brand, Robert L. Gibson, Bruce McCandless II, Ronald E. McNair and Robert L. Stewart. Brand is making his first trip in the Challenger but his second STS flight and third spaceflight overall. The rest of the crew members are experiencing space travel for the first time. Marking a space first, this flight will be landing at KSC. Photo credit: NASA

S89-41091 (18 July 1989) --- During the Terminal Countdown Demonstration Test (TCDT), STS-28 crew members are assisted with suiting up in the Operations and Checkout Building prior to departing for pad 39-B. STS-28 and the Space Shuttle Columbia are scheduled to be launched in early August on a Department of Defense dedicated mission. The crew for STS-28 are Commander Brewster H. Shaw; Pilot Richard N. Richards; and Mission Specialists Mark N. Brown, James C. Adamson, and David C. Leestma.

STS-128 commander Rick Sturckow speaks to the audience during a presentation in the auditorium at NASA Headquarters in Washington, Thursday, Nov. 5, 2009. Photo Credit: (NASA/Paul E. Alers)

STS-128 mission specialist Patrick Forrester speaks to the audience during a presentation in the auditorium at NASA Headquarters in Washington, Thursday, Nov. 5, 2009. Photo Credit: (NASA/Paul E. Alers)

At a media showcase in the Space Station Processing Facility, reporters and photographers get a close look at the S3/S4 integrated truss segment. The starboard 3/4 truss segment will launch aboard Space Shuttle Atlantis on mission STS-117, targeted for March 15. The element will be added to the 11-segment integrated truss structure, the station's backbone. The integrated truss structure eventually will span more than 300 feet. The S3/S4 truss has two large solar arrays and will provide one-fourth of the total power generation for the completed station.

In the Space Station Processing Facility, photographers take advantage of a media showcase to get photos of the S3/S4 integrated truss segment. The starboard 3/4 truss segment will launch aboard Space Shuttle Atlantis on mission STS-117, targeted for March 15. The element will be added to the 11-segment integrated truss structure, the station's backbone. The integrated truss structure eventually will span more than 300 feet. The S3/S4 truss has two large solar arrays and will provide one-fourth of the total power generation for the completed station.

Lake St. Clair connects Lake Huron, via the St. Clair River, to Lake Erie, via the Detroit River. It is named after Claire of Assisi, on whose feast day it was first navigated by French explorers in 1679. The lake covers an area of about 1100 square kilometers, with an average depth of 3.5 meters. Both the U.S. and Canada maintain a deep shipping channel through the lake. The image was acquired September 9, 2002, covers an area of 51.4 by 52.5 kilometers, and is located at 42.5 degrees north, 82.7 degrees west. https://photojournal.jpl.nasa.gov/catalog/PIA23234

NASA Administrator Charles Bolden watches as a truck sprays water on the crawler way to help minimize dust as the space shuttle Atlantis (STS-135), atop of the Mobile Launch Platform (MLP), rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden looks at the large crowds gathered from atop of the Mobile Launch Platform (MLP) as the space shuttle Atlantis (STS-135) rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

A truck sprays water on the crawler way to help minimize dust as the space shuttle Atlantis (STS-135), atop of the Mobile Launch Platform (MLP), rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

Commander Christopher Ferguson (left) and Mission Specialist Heidemarie Stefanyshyn-Piper, both members of the STS-126 shuttle mission, sign autographs for Stennis employees Jan. 13 during a visit to StenniSphere.

Commander Christopher Ferguson (right) and Mission Specialist Heidemarie Stefanyshyn-Piper, both members of the STS-126 shuttle mission, share highlights of their trip to the International Space Station during their Jan. 13 visit to StenniSphere.

Media members interview Commander Christopher Ferguson (right) during his Jan. 13 visit to StenniSphere. He was joined by Mission Specialist Heidemarie Stefanyshyn-Piper (on stage, left), both members of the STS-126 shuttle mission.

STS-135 Commander Chris Ferguson, right, talks with NASA Administrator Charles Bolden atop of the Mobile Launch Platform (MLP) as the space shuttle Atlantis (STS-135) rolls out of High Bay 3 in the Vehicle Assembly Building to Launch Pad 39a for its final flight, Tuesday evening, May 31, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The 3.4-mile trek, known as "rollout," will take about seven hours to complete. Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The launch of STS-135 is targeted for July 8. Photo Credit: (NASA/Bill Ingalls)

A special event honoring the crew of space shuttle mission STS-118 was held at Walt Disney World. Here, visitors enjoy the NASA display at Epcot's Innoventions Center. The event also honored teacher-turned-astronaut Barbara R. Morgan, who dedicated a plaque outside the Mission: Space attraction. Other activities included meeting with the media and students and a parade down Main Street. Mission STS-118 was the 119th shuttle program flight and the 22nd flight to the International Space Station. Space shuttle Endeavour launched from NASA's Kennedy Space Center on Aug. 8 and landed Aug. 21. The mission delivered the S5 truss, continuing the assembly of the space station.

STS051-S-002 (June 1993) --- These five NASA astronauts have been assigned to fly aboard the Space Shuttle Discovery for the STS-51 mission, scheduled for July, 1993. Left to right are astronauts Frank L. Culbertson, Jr., mission commander; Daniel W. Bursch and Carl E. Walz, mission specialists; William F. Readdy, pilot; and James H. Newman, mission specialist.

STS036-S-002 (21 Nov. 1989) --- The five astronauts in training for STS-36 pose near the Space Shuttle Discovery on Launch Pad 39B. Astronaut John O. Creighton (center) is mission commander. Others pictured are (left to right) astronauts Pierre J. Thuot, John H. Casper, Richard M. (Mike) Mullane and David C. Hilmers. Casper is pilot and the other three are mission specialists for the DOD-devoted mission.

STS043-S-002 (May 1991) --- These five astronauts have been assigned to fly aboard the Space Shuttle Atlantis for NASA's STS-43 mission. Astronaut John E. Blaha (center) is mission commander. Other crew members are, left to right, astronauts Shannon W. Lucid, James C. Adamson and G. David Low, all mission specialists; and Michael A. Baker, pilot.

STS098-365-0034 (7-20 February 2001) --- The crew of the STS-98 mission poses for the traditional inflight portrait on the flight deck of the Space Shuttle Atlantis. From left are astronauts Kenneth D. Cockrell, mission commander; Marsha S. Ivins, mission specialist; Thomas D. Jones, mission specialist; Mark L. Polansky, pilot; and Robert L. Curbeam, mission specialist.

Canadian Space Agency Astronaut and STS-127 Mission Specialist Julie Payette answers questions at the NASA Tweetup event held at NASA Headquarters, September 24, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (NASA/Carla Cioffi)

NASA Astronaut and STS-127 Mission Commander Mark Polansky, left, answers questions at the NASA Tweetup event held at NASA Headquarters, September 24, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (NASA/Carla Cioffi)

STS-129 Mission Specialist Randy Bresnick, second from right, answers a question from the audience as fellow crew members look on, Monday, Jan. 11, 2010, during a presentation to staff and middle school students from the Congressional Schools of Virginia at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

Barbie Dolls stand by during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

Actor and Producer Levar Burton tweets with two devices during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

NASA Astronaut Clay Anderson speaks to NASA Twitter followers during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

Actor Seth Green, a NASA Twitter follower, tweets from his device during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

NASA Astronaut Mike Massimino, known as "Astro_Mike" on Twitter, prepares to give a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

Heather Good, Twitter handle @foundonmars, tweets during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

STS-129 Pilot Barry Wilmore, left, answers a question from the audience as Mission Specialist Leland Melvin, looks on, Monday, Jan. 11, 2010, during a presentation to staff and middle school students from the Congressional Schools of Virginia at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Astronaut and STS-127 Mission Commander Mark Polansky, also known as @Astro_127 on Twitter, answers questions at the NASA Tweetup event held at NASA Headquarters, September 24, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (NASA/Carla Cioffi)

European Space Agency astronaut Christer Fuglesang, a mission specialist on STS-128, far right, smiles during a presentation in the auditorium at NASA Headquarters in Washington, Thursday, Nov. 5, 2009. Photo Credit: (NASA/Paul E. Alers)

STS-129 Mission Specialist Robert Satcher, lower right, interacts with the audience as he and fellow crew members sign autographs, Monday, Jan. 11, 2010, following a presentation to staff and middle school students from the Congressional Schools of Virginia at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

STS-129 Mission Specialist Leland Melvin, answers a question as fellow crew members look on, Monday, Jan. 11, 2010, during a presentation to staff and middle school students from the Congressional Schools of Virginia at NASA Headquarters in Washington. Photo Credit: (NASA/Paul E. Alers)

NASA Astronaut Mike Massimino, known as "Astro_Mike" on Twitter, answers a question during a presentation with fellow STS-125 shuttle mission crew members at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

NASA Twitter followers are seen through a space suit helmet during the STS-134 Tweetup, Thursday, April 28, 2011, at Kennedy Space Center in Cape Canaveral, Fla. About 150 NASA Twitter followers attended the event. Photo Credit: (NASA/Paul E. Alers)

NASA Astronaut and STS-125 Mission Pilot Scott Altman answers questions at the NASA Tweetup event held at NASA Headquarters, July 21, 2009 in Washington. Nearly 200 of NASA’s Twitter followers are in attendance. Photo Credit: (Carla Cioffi)

Astronauts Steve Lindsey (left), Stephanie Wilson, Lisa Nowak and Piers Sellers meet with employees at NASA Stennis Space Center. The crewmembers on NASA's space shuttle mission STS-121, which launched July 4, 2006, thanked SSC's workers for their dedication and safe work history. `We feel blessed that you are a part of the NASA family,' Wilson said. All four expressed gratitude for the reliability of the space shuttle's main engines, which helped propel the STS-121 crew into orbit on their 13-day mission.

Space shuttle Atlantis is seen on launch pad 39a moments after the STS-135 crew arrived for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at Kennedy Space Center on the STS-135 mission, Friday, July 8, 2011 in Cape Canaveral, Fla. Atlantis launched on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will deliver the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Dick Clark)

NASA astronaut Mike Massimino, far left, Sesame Street's Elmo and NASA astronaut Doug Wheelock, far right, speak at the STS-135 Tweetup, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla. Elmo asked the astronauts questions about living and working in space. About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

The crew of STS-135 is seen as they depart the NASA Kennedy Space Center, Operations and Checkout Building and get into the Astrovan for launch pad 39A, on Friday, July 8, 2011 in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

The Astrovan carrying the STS-135 crew; Chris Furgeson, commander, Doug Hurley, pilot, and mission specialists Rex Walheim and Sandy Mangus, rolls toward launch pad 39a and space shuttle Atlantis, Friday, July 8, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The Astrovan carrying the STS-135 crew; Chris Furgeson, commander, Doug Hurley, pilot, and mission specialists Rex Walheim and Sandy Mangus, rolls past the Vehicle Assembly Building (VAB) and Launch Control Center (LCC), on its way to launch pad 39a and space shuttle Atlantis, Friday, July 8, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

STS-135 Tweetup participants are seen outside launch pad 39a and space shuttle Atlantis following the Rotating Service Structure rollback, Thursday, July 7, 2011, at Kennedy Space Center in Cape Canaveral, Fla.About 150 NASA Twitter followers attended the event. The STS-135 mission will be NASA's last space shuttle launch. Photo Credit: (NASA/Paul E. Alers)

Space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at Kennedy Space Center on the STS-135 mission, Friday, July 8, 2011 in Cape Canaveral, Fla. Atlantis launched on the final flight of the shuttle program on a 12-day mission to the International Space Station. The STS-135 crew will deliver the Raffaello multipurpose logistics module containing supplies and spare parts for the space station. Photo Credit: (NASA/Dick Clark)

Space shuttle Atlantis is seen on launch pad 39a moments before the STS-135 crew arrives for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Atlantis is seen on launch pad 39a moments before the STS-135 crew arrives for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

STS-134 mission Commander Mark Kelly is seen preparing to enter space shuttle Endeavour on a monitor in Firing Room Four of the Launch Control Center (LCC), Monday, May 16, 2011, at the Kennedy Space Center in Cape Canaveral, Fla. During the mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Atlantis is seen on launch pad 39a moments after the STS-135 crew arrived for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

NASA Launch Director Michael Leinbach congratulates the launch team in the NASA Kennedy Space Center Firing Room Four of the Launch Control Center (LCC) shortly after the space shuttle Atlantis, STS-135, launched on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

NASA Administrator Charles Bolden congratulates Launch Director Michael Leinbach, facing camera, in Firing Room Four of the Launch Control Center (LCC) shortly after the space shuttle Atlantis, STS-135, launched on Friday, July 8, 2011, in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The Astrovan carrying the STS-135 crew; Chris Ferguson, commander, Doug Hurley, pilot, and mission specialists Rex Walheim and Sandy Mangus, arrives at launch pad 39A and space shuttle Atlantis, Friday, July 8, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The STS-135 crew; Chris Ferguson, commander; Doug Hurley, pilot; Rex Walheim and Sandy Magnus, both mission specialists are seen before boarding space shuttle Atlantis at launch pad 39A prior to launch, Friday, July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The STS-135 crew; Chris Ferguson, commander; Doug Hurley, pilot; Rex Walheim and Sandy Magnus, both mission specialists are seen before boarding space shuttle Atlantis at launch pad 39A prior to launch, Friday, July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Atlantis is seen on launch pad 39a moments before the STS-135 crew arrives for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Space shuttle Atlantis is seen on launch pad 39a moments after the STS-135 crew arrived for their launch, Friday, July 8, 2011, at the NASA Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The Astrovan carrying the STS-135 crew; Chris Ferguson, commander, Doug Hurley, pilot, and mission specialists Rex Walheim and Sandy Mangus, arrives at launch pad 39A and space shuttle Atlantis, Friday, July 8, 2011, at Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The STS-135 crew, clockwise: Sandra Magnus, mission specialist; Rex Walheim, mission specialist; Chris Ferguson, commander and Doug Hurley, pilot are seen in the Astrovan as they ride to launch pad 39A to board space shuttle Atlantis on Friday, July 8, 2011, at the Kennedy Space Center in Cape Canaveral, Fla. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. Photo Credit: (NASA/Jerry Ross)

The space shuttle Atlantis (STS-122) lands at the Shuttle Landing Facility, 9:07a.m., Wednesday, Feb. 20, 2008 at Kennedy Space Center, Fla. completing delivery of the European Space Agency’s (ESA) Columbus laboratory to the International Space Station. Photo Credit: (NASA/Bill Ingalls)

STS098-333-0007 (7-20 February 2001) --- A "sunburst" at Earth's limb caught the attention of one of the STS-98 astronauts who was standing on the aft flight deck of the Space Shuttle Atlantis at the time. Various colors are reflected at different points in the 35mm frame.

Crew members of space shuttle mission STS-120 prepare to board the bus that will transport them to Launch Pad 39A.

NASA STS-130 Pilot Terry Virts, right, is interviewed by Mid-Atlantic Sports Network (MASN) reporter Debbie Taylor at Nationals Park Tuesday, April 20, 2010, in Washington. Photo Credit: (NASA/Carla Cioffi)

NASA STS-130 Pilot Terry Virts throws the opening pitch at Nationals Park on Tuesday, April 20, 2010, in Washington. Photo Credit: (Courtesy of the Washington Nationals)

NASA STS-130 Pilot Terry Virts, center, is interviewed by Washington Nationals radio broadcasters Charlie Slowes, right, and David Jageler on Tuesday, April 20, 2010, in Washington. Photo Credit: (NASA/Carla Cioffi)

A replica of the Nobel Prize that is in the museum's collection and was flown aboard STS-132 Atlantis is seen, Tuesday, July 27, 2010, at the Smithsonian National Air and Space Museum in Washington. STS-132 astronaut Piers Sellers returned the replica during a ceremony at the museum. Photo Credit: (NASA/Paul E. Alers)