The third servicing mission of the Hubble Space Telescope, which was placed into orbit in 1990, occurred during the STS-103 mission in December 1999. During the mission, it was originally planned for June 2000 but was accelerated by six months after unexpected failures of the telescope’s attitude control gyroscopes. , the astronauts restored the facility to full functionality. During its eight-day mission, it was the first space shuttle crew to spend. Christmas in spacea seven-member American and European crew rendezvoused with and captured Hubble, and four astronauts in rotating teams of two undertook three long and complex spacewalks to service and upgrade the telescope. They re-deployed the telescope with greater capabilities to continue its mission of helping scientists uncover the secrets of the universe.
Discovered by the Hubble Space Telescope Launched in 1990. That its primary mirror suffered from a flaw known as spherical aberration frustrated scientists who could not get the sharp images they had hoped for. But thanks to Hubble’s built-in feature of on-orbit servicing, NASA planned to fix the telescope’s optics. First planned repair mission In 1993 A second servicing mission in 1997 upgraded the telescope’s capabilities until the next mission was planned three years later. But after three of the telescope’s six gyroscopes failed in 1997, 1998 and 1999, mission rules mandated a call-up mission in the event of additional gyroscope failures to send Hubble into safe mode. NASA chose to carry over some servicing tasks from the third mission, splitting it into Missions 3A and 3B, planning to fly 3A in October 1999 primarily to replace failed gyroscopes on Discovery’s STS-103 mission. . Irregularities during the launch resulted in delays in the shuttle fleet STS-93 STS-103 launched in July 1993, first in November and finally in December. Technical problems with Discovery itself pushed the launch date to mid-December, and raised concerns about keeping the shuttle in orbit during the Y2K transition. Once the launch slipped to Dec. 19, mission planners cut the mission from 10 to eight days, deleting one of the four spacewalks, to ensure a return before the end of the calendar year. The servicing mission could not come soon enough, as the fourth gyroscope failed on Hubble in mid-November, with Discovery already on the launch pad in preparation for STS-103. Controllers kept Hubble in safe mode until the astronauts arrived.
To carry out the third Hubble servicing mission, in July 1998 NASA selected an experienced four-person team to fly a record-breaking six spacewalks, then planned for June 2000. Spacewalkers included mission experts. Steven L. Smith Serving as Payload Commander, John M. Grinsfield, C. Michael Foaleand European Space Agency (ESA) astronauts Claude Nicollier Commander added in March 1999 from Switzerland Curtis L. Brownthe pilot Scott J. Kellyand mission specialist ESA astronauts Jean-François A. Clervoy France assembled a highly experienced crew with 18 previous space flights between them. Brown became only the fifth person to fly in space six times. For Kelly, STS-103 marked his first space flight. Smith, Kilroy, and Grinsfeld had each flown two previous missions, Foley four including one long-duration mission aboard Mir and Nicollier three. Smith participated in three spacewalks during the second Hubble servicing mission and Nicollier served as the remote manipulator system (RMS) or robotic arm operator during the first.
Discovery returned to KSC at the end of the STS-96 mission on June 6, 1999, and workers began preparing it for STS-103, taking it to the Orbiter Processing Facility that same day. The vehicle arrived at the Vehicle Assembly Building on November 4, where workers assembled its external tank and twin solid rocket boosters, before rolling out the stack to Launch Pad 39B on November 13.
It started on the 27thTh Journey into Space Discovery lifted off from Launch Pad 39B at 7:50 pm EST on December 19 to repair the ailing space telescope. Two days later, Brown and Kelly maneuvered Discovery into Hubble’s orbit so that Kilroy, operating the 50-foot-tall RMS, could grab the telescope and move it into the payload bay.
Smith and Grinsfield performed the mission’s first spacewalk on December 22, the fourth day of spaceflight. With the help of Clervoy operating the RMS from within Discovery, the pair accomplished two of the mission’s highest priority objectives. They replaced the failed gyroscopes, installing three new rate sensor units, each with two gyroscopes, to return control to the ailing telescope. They also installed six voltage/temperature optimization kits to prevent the telescope’s batteries from overheating as they age. The walk lasted eight hours and 15 minutes, the second-longest spacewalk at the time.
The next day, Nicollier and Foyle performed the mission’s second spacewalk. The main task of this excursion was to install a new computer on Hubble to replace the 1970s vintage unit. The new radiation-hardened system runs 20 times faster and carries six times more memory while using one-third the electrical power. They also installed a fine guidance sensor before completing the eight-hour, 10-minute spacewalk.
Smith and Grinsfeld took off a second time on December 24 to complete the third and final spacewalk of the flight, the first spacewalk being performed on Christmas Eve. First, they replaced an old reel-to-reel tape recorder with a solid-state unit that increased recording capacity by 10 times and replaced a failing data transmitter. They installed seven new covers on Hubble’s electronics bay doors for additional protection of the telescope’s insulation. This third spacewalk lasted for eight hours and eight minutes.
The next day, the STS-103 astronauts earned the distinction of being the first space shuttle crew to expend. Christmas Day in Space. Kilroy grabbed Hubble, pulled it out of the payload bay and released it to continue its mission. “The spacecraft is being guided by its new gyros under the control of its brand new computer,” John H. Campbell, Hubble Space Telescope program manager, said after the release. [It] Now circulating freely and in excellent shape. After deploying Hubble, the astronauts enjoyed a hearty Christmas dinner, with Culroy providing French cuisine. The crew spent December 26th preparing Discovery for its return to Earth, including testing its reaction control system thrusters and aerodynamic surfaces and stowing non-essential equipment.
On December 27, the astronauts donned their launch and entry suits and prepared to return to Earth. They closed the payload bay doors and fired Discovery’s engines to bring them out of orbit. Just before landing, Kelly lowered the craft’s landing gear and Brown guided Discovery to a smooth night landing at KSC, ending a seven-day, 23-hour, 11-minute flight. He circled the earth 119 times. This flight marked Discovery’s last solo flight as all subsequent missions docked with the International Space Station. KSC workers began preparing him for his next mission, STS-92 In October 2000
The Hubble Space Telescope continues to operate today, far exceeding its expected five-year life extension. The last of the servicing missions In 2009 Joined in space by the James Webb Space Telescope in 2021, the two instruments together continue to image the skies across a wide range of the electromagnetic spectrum to give scientists unprecedented insight into the universe and its formation. Can provide equipment.
See STS-103 crew statement Video of their Hubble servicing mission.