2010 American crewed spaceflight to the ISS
STS-131 (ISS assembly flight 19A) was a NASA Space Shuttle mission to the International Space Station (ISS). Space Shuttle "Discovery" launched on April 5, 2010, at 6:21 am from LC-39A, and landed at 9:08 am on April 20, 2010, on runway 33 at the Kennedy Space Center's Shuttle Landing Facility. The mission marked the longest flight for Space Shuttle "Discovery" and its 38th and penultimate flight.
The primary payload was a Multi-Purpose Logistics Module loaded with supplies and equipment for the International Space Station. The mission also removed and replaced an ammonia tank assembly outside the station on the S1 truss. STS-131 furthermore carried several on-board payloads; this mission had the most payloads since STS-107. It is also the last shuttle mission with a crew of 7.
Mission payload.
Multi-Purpose Logistics Module "Leonardo".
The primary payload of STS-131 was the Multi-Purpose Logistics Module (MPLM) "Leonardo". The MPLM was filled with food and science supplies for the International Space Station (ISS). The MPLM also carried the third and final Minus Eighty Degree Laboratory Freezer for ISS (MELFI), Window Orbital Research Facility (WORF), one Crew Quarters Rack, the Muscle Atrophy Resistive Exercise (MARES) rack, Resupply Stowage Racks (RSRs), and Resupply Stowage Platforms (RSPs).
Lightweight Multi-Purpose Equipment Support Structure Carrier.
The Lightweight Multi-Purpose Equipment Support Structure Carrier (LMC) carried a refurbished Ammonia Tank Assembly (ATA) to the ISS. The refurbished ATA was removed from the Space Station and returned for use on this mission during STS-128. It was swapped with an empty tank which will ride home on the LMC.
TriDAR.
This mission was the second flight of the TriDAR, a 3D dual-sensing laser camera, intended for potential use as an autonomous rendezvous and docking sensor. TriDAR provides guidance information that can be used to guide a vehicle during rendezvous and docking operations in space. TriDAR does not rely on any reference markers, such as reflectors, positioned on the target spacecraft. To achieve this, it relies on a laser based 3D sensor and a thermal imager. Geometric information contained in successive 3D images is matched against the known shape of the target object to calculate its position and orientation in real-time. The TriDAR tracked the ISS position and orientation from the shuttle during docking, undocking, and flyaround operations.
Mission milestones.
The mission marked:
Shuttle processing.
Space Shuttle "Discovery" was moved from its hangar in the Orbiter Processing Facility (OPF) 3 to the nearby Vehicle Assembly Building (VAB) on February 22, 2010. The rollover was completed around 10:30 EST. According to NASA, the rollover occurred a day earlier than announced to take advantage of favorable weather in advance of poor conditions forecasted on the next day.
An earlier plan to move "Discovery" into the VAB on February 12, 2010, was delayed because of cold weather at the Kennedy Space Center. For the rollover, temperatures in the VAB had to be above for more than twelve hours because "Discovery" was not attached to any heating purges to protect its systems from potential damage from the cold.
Space Shuttle "Discovery" began its trip, known as the rollout, to LC-39A at 23:58 EST on March 2, 2010. The complete shuttle stack and mobile launcher platform were secured to the LC-39A structure at 6:49 EST on March 3, 2010. The trek took 6 hours 51 minutes to complete. The rollout was delayed 24 hours by the threat of lightning from a passing cold front. That weather moved away, and the stiff wind gusts blowing on Florida's Space Coast on the next day were not a factor for the rollout. Ahead of the rollout, engineers noticed some damage caused by birds to the External Tank (ET-135), which was repaired inside the VAB. Birds had managed to reach the tank, and pecked away at the Thermal Protection System (TPS) foam.
Mission timeline.
April 5 (Flight Day 1 – Launch).
"Discovery" lifted off successfully at 06:21 EDT, marking this launch as the last night launch in the Space Shuttle program. After the 8 1/2-minute ride to space, "Discovery"'s seven person crew began configuring the orbiter from a launch vehicle to an orbital vehicle. Commander Alan Poindexter and pilot Jim Dutton, with help from mission specialist 2 Dorothy Metcalf-Lindenburger, also performed a series of engine firings or burns to adjust their speed and refine their path to the International Space Station. While the engine burns were going on, the rest of the crew opened the payload bay doors, set up the computers and Ku band antenna. The antenna suffered a failure during normal checkout and setup on orbit. Due to the failure, the normal downlink of imagery of the external tank was not completed. The crew on board will monitor the inspections of the thermal protection system (TPS) in real time and will note any spots of interest and let the ground know while downlinking the imagery after docking. The dish antenna also serves as a radar antenna, measuring the distance to the space station.
April 6 (Flight Day 2 – Inspections).
The seven person crew of STS-131 was awakened to begin their first full day in space on Flight Day 2. Due to the lack of Ku-band communication, changes to the crews daily plan were read up for them to write out. After their post sleep activities, commander Alan Poindexter and pilot Jim Dutton fired "Discovery"'s Orbital Maneuvering System (OMS) engines to correct and further refine the shuttle's path to the ISS. Astronauts Naoko Yamazaki and Dorothy Metcalf-Lindenburger began activating and checking out the Shuttle Remote Manipulator System (SRMS) also known as the Canadarm. While Metcalf-Lindenburger and Yamazaki were working with Canadarm, Stephanie Wilson was getting equipment together and set up to record the inspections of the shuttle's heat shield. The inspections were recorded so they could be downlinked to the ground once docked to the ISS. Once all that work was done, commander Poindexter and pilot Dutton joined Metcalf-Lindenburger, Yamazaki, and Wilson to conduct the inspection of the shuttle's heat shield. While the inspection was going on, Rick Mastracchio and Clayton Anderson were on the mid-deck of "Discovery" checking out the Extravehicular Mobility Units (EMU) and getting them ready for their three spacewalks. The last portion of the crew day was spent preparing and checking out all of the tools used during rendezvous.
April 7 (Flight Day 3 – Docking).
Space Shuttle "Discovery" successfully docked with the space station at 07:44 UTC (03:44 EDT) on April 7, 2010, as the two spacecraft sailed 220 miles above the Caribbean. The crew performed six successful engine firings to set up the on-time docking. Prior to docking commander Poindexter guided "Discovery" through the standard Rendezvous Pitch Maneuver (RPM). Station commander Oleg Kotov and flight engineer T.J. Creamer took more than 350 photos of "Discovery"'s heat shield. Once "Discovery" docked to the International Space Station (ISS), a series of leak checks were done on both sides of the hatch by the shuttle and station crews. The hatches between the two vehicles were opened at 09:11 UTC (05:11 EDT), which was 30 minutes earlier than planned. Once the hatches were opened the STS-131 crew got a safety briefing from the station crew, then began to transfer items that would be needed for later in the day and early on flight day 4. Two items that were transferred were the two EMUs that will be used for the three spacewalks. The crew also completed a grapple of the Orbiter Boom Sensor System (OBSS) with the Space Station Remote Manipulator System (SSRMS) also known as Canadarm2. Once the OBSS was grappled it was unberthed from the starboard sill of the space shuttle payload bay, and handed off to the SRMS. Throughout the day, after docking to the station, the shuttle crew began downlinking all of the inspection video from flight day 2, and launch imagery and video.
April 8 (Flight Day 4 – MPLM ingress).
On flight day 4, Stephanie Wilson and Naoko Yamazaki grappled and berthed the Multi-purpose Logistics Module (MPLM) "Leonardo". The MPLM was berthed to the station at 04:24 UTC (00:24 EDT). The hatches were opened by station flight engineer Soichi Noguchi and shuttle mission specialist Clayton Anderson at 11:58 UTC (07:58 EDT). The joint STS-131/Expedition 23 crews began transferring cargo from the MPLM, with the first item being a Rate Gyro Assembly (RGA) which will be replaced on the first spacewalk of the mission. During flight day 4, commander Alan Poindexter did several in-flight interviews. Commander Poindexter was joined by mission specialists Rick Mastracchio and Stephanie Wilson. The interviews were with the "Tom Joyner Radio Show", WVIT-TV and Fox News Radio. At the end of the day, Mastracchio and Anderson entered the Quest airlock and begin breathing pure oxygen for an hour, while the atmospheric pressure inside the airlock was lowered to 10.2 psi. This procedure is known as the pre-breathe protocol and is done before every spacewalk, to purge nitrogen from the blood stream and prevent decompression sickness.
April 9 (Flight Day 5 – EVA 1).
Flight day 5 saw the completion of the first spacewalk by Rick Mastracchio and Clayton Anderson. The pair released the new ammonia tank assembly for transfer to station for installation on a later spacewalk. They also removed an experiment from outside on the Kibo Exposed Facility, replaced a Rate Gyro Assembly (RGA) and performed several get-ahead tasks. The spacewalking pair was assisted by the SSRMS which was operated by pilot Jim Dutton and mission specialist Stephanie Wilson. While the spacewalk took place, Naoko Yamazaki was assisted by commander Alan Poindexter, and the Expedition 23 crew to move several of the large science racks from the MPLM "Leonardo" to their new location on the ISS.
April 10 (Flight Day 6 – Transfers).
Flight day 6 was dedicated to transferring supplies from the MPLM "Leonardo" and the Space Shuttle mid-deck. The crews transferred the Windows Observational Research Facility (WORF) to the Destiny lab. Mission specialist Naoko Yamazaki, along with flight engineer Soichi Noguchi also transferred the Express Rack 7 (ER7) to its final location. During the crews morning, a smoke alarm sounded in the Russian segment of the station, which prompted the joint crew to move into emergency procedures. However the alarm was false and was cleared within a couple of minutes and all normal work resumed. Mission specialists Clay Anderson, Rick Mastracchio and Stephanie Wilson conducted in-flight interviews with Nebraska Public Radio, CBS Newspath and Radio Network and KETV-TV in Omaha, Nebraska. Later in the day commander Alan Poindexter, pilot Jim Dutton and mission specialist Dorothy Metcalf-Lindenburger talked with students at the Naval Postgraduate School in Monterey, California. At the end of the crews work day, the joint crew got together and reviewed the procedures for the second spacewalk. After the procedures review spacewalkers Clay Anderson and Rick Mastracchio entered the Quest airlock, closed the hatch and lowered the inside pressure to 10.2 psi. The pair also breathed pure oxygen for an hour while the pressure was being lowered.
April 11 (Flight Day 7 – EVA 2).
On flight day 7, astronauts Clay Anderson and Rick Mastracchio performed their second spacewalk of the STS-131 mission. Mastracchio and Anderson exited the airlock at 05:30 UTC, a full 45 minutes ahead of the planned time, and spent 7 hours and 26 minutes outside the ISS. The pair removed the old Ammonia Tank Assembly (ATA) from the S1 truss and installed the new ATA. Anderson and Mastracchio ran into a small problem when one of the four bolts that holds the tank in place wouldn't turn. They loosened the other three and tried them all again and the fourth bolt was successfully tightened. The two spacewalkers helped guide the SSRMS to temporarily stow the old ATA on the truss structure. The new ATA had its electrical connections made, but the fluid connections were deferred until the third spacewalk since the EVA was behind the time-line. Mastracchio and Anderson also installed two radiator grapple fixture stowage beams on the P1 truss. While Anderson and Mastracchio were outside, members of the STS-131 crew continued transferring items from Space Shuttle "Discovery"'s mid-deck and the MPLM "Leonardo". Overall, the crew had completed about half of the transfer work.
April 12 (Flight Day 8 – Off duty).
The joint STS-131/Expedition 23 crews had the morning off on flight day 8. After their morning off the crews continued their transfer activities, which are more than seventy percent complete. The crews also conducted several PAO events, including VIP events with Roscosmos, Russian