Our Spaceflight Heritage: Shuttle launch for Independence Day
On Independence Day, July 4, 2006, space Shuttle Discovery lifted off at 2:37 p.m. EDT with six astronauts aboard and two tons of cargo to be delivered to the International Space Station, including the fourth trip for the Multi-Purpose Logistics Module (MPLM) Leonardo.
Led by commander Steve Lindsey and pilot Mark Kelly, the STS-121 crew included mission specialists Michael E. Fossum, Lisa M. Nowak, Stephanie D. Wilson, Piers J. Sellers, and Thomas A. Reiter of the European Space Agency. Reiter would join Expedition 13 Commander Pavel Vinogradov and Flight Engineer and NASA Science Officer Jeffrey Williams, the first crew aboard ISS to include three astronauts since the Expedition 6 crew returned to Earth May 4, 2003. The Expedition crew also became the first to include an American, a Russian and a European.
This was the first spaceflight for Fossum, Nowak, and Wilson and the second for Kelly and Sellers. The purpose of STS-121 was to test new equipment and procedures for the inspection and repair of the thermal protection system that is designed to increase the safety of the Space Shuttles. Italian built MPLM Leonardo carried a Minus Eighty Degree Laboratory Freezer (MELFI), a European Modular Cultivation System (EMCS) for biological experiments, a new oxygen generation system in the Zvezda module, and a Cycle Ergometer with Vibration Isolation System (CEVIS) cycling machine installed in the Destiny Laboratory module. On July 5, Discovery’s crew focused on inspecting the orbiter’s thermal protection system.
The inspection took several hours and the astronauts found no evidence of any damage from the flight. During flight day four, the astronauts removed the Leonardo module from Discovery’s payload bay using the shuttle’s robotic arm to attach it to the Unity module of the International Space Station. After Leonardo was in place, they began unloading more than 7,000 pounds of equipment and supplies. When the module was emptied out, it was refilled with almost 4,400 pounds of unneeded and broken equipment, scientific experiment results and trash for transport back to Earth. STS-121 included three spacewalks which were all carried out by Sellers and Fossum. The first EVA during flight day five lasted seven and a half hours while Sellers and Fossum tested the 50-foot (15 m) Orbital Boom Sensor System extension to the robotic arm.
Two days later the mission specialists deployed a spare pump module and replaced a reel of umbilical cable carrying power, data and video for operating the station’s Mobile Transporter rail car in six hours and forty-seven minutes. An extra day allowed a third spacewalk to test thermal protection system repair techniques and evaluate a thermal imaging camera.The last spacewalk occurred on July 12where Fossum and Sellers tested pre-damaged samples of heat shield brought to space and placed in Discovery’s payload bay.
Wilson and Nowak used the station’s robotic arm to return the Leonardo module to Discovery’s payload bay on July 14. Undocking from the station occurred at 6:08 a.m. the next day to begin the two-day trip back to Earth. On July 17, Discovery’s deorbit engines were fired for three minutes at 8:07 a.m. EDT above the Indian Ocean to begin the descent.
Discovery touched down on runway 15 at the Shuttle Landing Facility at 8:15 a.m. EDT, completing 12 days, 18 hours and 38 minutes in space covering 5.3 million miles. STS-121 was the only space shuttle mission that launched on the United States’ Day of Independence.
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Heather Smith's fascination for space exploration – started at the tender age of twelve while she was on a sixth-grade field trip in Kenner, Louisiana, walking through a mock-up of the International Space Station and seeing the “space potty” (her terminology has progressed considerably since that time) – she realized at this point that her future lay in the stars. Smith has come to realize that very few people have noticed how much spaceflight technology has improved their lives. She has since dedicated herself to correcting this problem. Inspired by such classic literature as Anne Frank’s Diary, she has honed her writing skills and has signed on as The Spaceflight Group’s coordinator for the organization’s social media efforts.