NASA's Space Shuttle Discovery STS-128: Mission Objectives, Crew Contributions, and Lasting Impact on Space Exploration
NASA's Space Shuttle Discovery, one of the most significant and storied spacecraft in the history of space exploration, embarked on its STS-128 mission on August 28, 2009. This mission was a critical chapter in the ongoing efforts to maintain and enhance the International Space Station (ISS), underscoring NASA's commitment to space exploration, scientific research, and international collaboration. The STS-128 mission, officially designated as ISS Assembly Flight 17A, was the 30th flight of Space Shuttle Discovery and the 128th shuttle mission overall.
This detailed account explores the purpose of the STS-128 mission, the crew involved, the challenges faced, the significance of the mission's objectives, and the legacy of Discovery's contributions to space exploration.
The Space Shuttle Discovery: A Brief Overview
Before delving into the specifics of the STS-128 mission, it's essential to understand the legacy of the Space Shuttle Discovery. As one of NASA's five orbiters, Discovery has played a pivotal role in numerous significant milestones in space exploration. First launched in 1984, Discovery has been part of a wide array of missions, including satellite deployments, scientific research, and, most notably, serving as the shuttle that launched the Hubble Space Telescope in 1990.
Discovery's legacy is marked by its involvement in some of NASA's most critical missions, including returning the shuttle program to flight after the Challenger disaster (STS-26) and the Columbia disaster (STS-114). By the time of the STS-128 mission, Discovery had already established itself as a workhorse of the shuttle fleet, known for its reliability and the breadth of missions it had supported.
The Objectives of STS-128
The primary objective of the STS-128 mission was to deliver supplies and equipment to the International Space Station (ISS) to support its ongoing operations and future expansions. The mission carried the Multi-Purpose Logistics Module (MPLM) Leonardo, packed with vital supplies, science experiments, and equipment. These materials were essential for the continued functioning of the ISS and for facilitating ongoing research in various scientific fields, including biology, physics, and Earth science.
The mission also included the replacement of critical hardware components on the ISS. Among the most significant of these was the replacement of an Ammonia Tank Assembly (ATA) on the station’s truss. Ammonia is used in the ISS’s cooling system to dissipate heat generated by onboard electronics and other systems, making the replacement of this tank a crucial task to ensure the station's continued operation.
Additionally, the STS-128 mission featured several spacewalks (also known as Extravehicular Activities or EVAs) to install new components, repair existing systems, and prepare the ISS for future expansions. These spacewalks were a testament to the mission's complexity and the skill required by the astronauts to perform tasks in the challenging environment of space.
The Crew of STS-128
The success of any space mission depends on the expertise, training, and collaboration of its crew. STS-128 was crewed by seven astronauts, each bringing unique skills and experience to the mission:
Frederick "Rick" Sturckow (Commander): A veteran astronaut, Sturckow had previously flown on three shuttle missions before STS-128. As the mission commander, he was responsible for the overall success of the mission, including the safety of the crew, the shuttle, and the successful completion of the mission's objectives.
Kevin Ford (Pilot): STS-128 was Ford's first spaceflight. As the pilot, he assisted the commander in operating the shuttle and played a crucial role in docking Discovery with the ISS.
Patrick Forrester (Mission Specialist 1): Forrester was a seasoned astronaut with experience in spacewalks. His primary responsibilities during STS-128 included conducting EVAs to replace the Ammonia Tank Assembly and perform other maintenance tasks on the ISS.
Jose Hernandez (Mission Specialist 2): Hernandez, a first-time flyer, was responsible for managing the MPLM Leonardo's transfer operations, ensuring that all cargo was safely and efficiently moved between the shuttle and the ISS.
John "Danny" Olivas (Mission Specialist 3): Another experienced astronaut, Olivas had previously flown on STS-117. During STS-128, he conducted EVAs, working alongside Forrester to perform critical repairs and installations on the ISS.
Christer Fuglesang (Mission Specialist 4): A European Space Agency (ESA) astronaut, Fuglesang was also experienced in spacewalks. His participation highlighted the international collaboration essential to the success of the ISS. He worked on several of the EVAs, contributing to the mission's complex tasks.
Nicole Stott (Mission Specialist 5): Stott, who joined the ISS as a Flight Engineer, was making her first trip to space. She was scheduled to stay on the ISS for an extended mission, replacing astronaut Tim Kopra, who had been on the station since July 2009.
This diverse and skilled crew was integral to the success of the STS-128 mission. Each member's expertise and ability to work together under the challenging conditions of space ensured that the mission's objectives were met efficiently and safely.
Launch and Mission Timeline
The launch of STS-128 was initially scheduled for August 25, 2009, but it faced several delays due to technical issues and weather conditions. The first delay was caused by a faulty valve in the shuttle's propulsion system, which required additional inspections and repairs. Subsequent delays were due to unfavorable weather conditions at the Kennedy Space Center in Florida, the launch site for the mission.
Finally, on August 28, 2009, at 11:59 PM EDT, Space Shuttle Discovery successfully lifted off from Launch Pad 39A at the Kennedy Space Center. The night launch was a spectacular sight, with the shuttle's powerful engines lighting up the night sky as it ascended into orbit.
Once in orbit, Discovery began its two-day journey to rendezvous with the ISS. During this time, the crew conducted various system checks and prepared for the docking maneuver. On August 30, Discovery successfully docked with the ISS, marking the beginning of the main phase of the mission.
Over the next eight days, the crew of STS-128 worked closely with the ISS crew to unload the MPLM Leonardo and transfer its contents to the station. The supplies included science experiments, spare parts, and crew provisions. The MPLM Leonardo also carried a new treadmill, named the Combined Operational Load-Bearing External Resistance Treadmill (COLBERT), humorously named after comedian Stephen Colbert following a public poll conducted by NASA.
Extravehicular Activities (EVAs)
One of the most challenging aspects of the STS-128 mission was the series of spacewalks required to install new equipment and perform maintenance on the ISS. The mission included three planned EVAs, each with specific objectives to enhance the station's capabilities and ensure its continued operation.
EVA 1: August 31, 2009
The first EVA was conducted by astronauts John Olivas and Nicole Stott. The primary objective of this spacewalk was to retrieve a 1,300-pound ammonia tank from the shuttle's payload bay and install it on the station's truss. The old ammonia tank was also removed and secured in the shuttle's payload bay for return to Earth.
This EVA lasted approximately 6 hours and 35 minutes. The operation required precise coordination between the spacewalkers and the crew inside the ISS, particularly with the use of the station's robotic arm, which was essential for moving the large and heavy tank into position.
EVA 2: September 2, 2009
The second EVA, conducted by Olivas and Christer Fuglesang, focused on replacing a Rate Gyro Assembly (RGA), part of the ISS's attitude control system. The spacewalkers also performed maintenance on the station's insulation and installed two new GPS antennas.
This EVA lasted around 6 hours and 39 minutes. The successful completion of these tasks was critical for maintaining the ISS's orientation and ensuring its ability to navigate and stabilize in orbit.
EVA 3: September 3, 2009
The third and final EVA of the STS-128 mission was again conducted by Olivas and Fuglesang. The primary task was to install a new S-band Antenna Structural Assembly (SASA) on the ISS's Z1 truss, which is essential for the station's communication systems. They also completed the installation of a Power and Data Grapple Fixture (PDGF) on the station's truss, enhancing the capabilities of the station's robotic arm.
This EVA lasted approximately 7 hours and 1 minute, making it the longest of the three. The successful completion of these tasks ensured that the ISS remained fully operational and capable of supporting future missions and expansions.
The Return Journey and Landing
After completing the primary objectives of the mission, including the successful transfer of supplies and the completion of all planned EVAs, the crew of STS-128 prepared for their return to Earth. On September 8, 2009, Space Shuttle Discovery undocked from the ISS and began its journey home.
The return journey involved a series of maneuvers to safely deorbit the shuttle and prepare for re-entry into Earth's atmosphere. This phase of the mission is always critical, as it requires precise calculations and execution to ensure the shuttle's safe descent and landing.
On September 11, 2009, after more than 13 days in space, Space Shuttle Discovery touched down at Edwards Air Force Base in California. The shuttle's landing at Edwards was due to unfavorable weather conditions at the Kennedy Space Center, the preferred landing site. Edwards Air Force Base has served as an alternative landing site for shuttle missions on numerous occasions, and it provides a large, dry lakebed for the shuttle to land safely.
The STS-128 mission was declared a success, with all mission objectives achieved and the crew returning safely to Earth. The mission's accomplishments added to the legacy of Space Shuttle Discovery and its role in supporting the ISS and advancing human space exploration.
Significance and Legacy of STS-128
The STS-128 mission was significant for several reasons. First and foremost, it contributed to the ongoing support and maintenance of the International Space Station, which remains a critical platform for scientific research and international collaboration in space. The delivery of essential supplies, the successful completion of challenging EVAs, and the installation of new hardware ensured that the ISS could continue to operate and support future missions.
The mission also demonstrated the effectiveness of international cooperation in space exploration. The inclusion of Christer Fuglesang, an ESA astronaut, highlighted the collaborative efforts between NASA and its international partners in maintaining and expanding the ISS. This cooperation is a hallmark of the ISS program, which brings together space agencies from around the world to achieve common goals in space exploration and research.
STS-128 was also a testament to the versatility and reliability of the Space Shuttle Discovery. As one of the most frequently flown orbiters in the shuttle fleet, Discovery's successful completion of the mission further solidified its reputation as a workhorse of NASA's space program.
The scientific research supported by the STS-128 mission, including the experiments delivered to the ISS, has contributed to our understanding of various scientific phenomena. The results of these experiments have implications for fields such as medicine, biology, and Earth science, demonstrating the broader impact of space exploration on life on Earth.
Conclusion
NASA's Space Shuttle Discovery launch on STS-128 was a mission that exemplified the complexities, challenges, and triumphs of human space exploration. The mission's success was the result of meticulous planning, skilled execution, and the dedication of the astronauts and ground teams involved. As a critical part of the ongoing efforts to support the International Space Station, STS-128 played a key role in ensuring the station's continued operation and its ability to serve as a platform for scientific research and international cooperation.
The legacy of STS-128 is one of collaboration, innovation, and the relentless pursuit of knowledge. It stands as a reminder of what humanity can achieve when we work together to explore the unknown and push the boundaries of what is possible.