STS-125

STS-125. This was the final Space Shuttle mission dedicated to servicing the Hubble Space Telescope. Launched aboard Space Shuttle Atlantis, the highly complex flight involved five challenging spacewalks to install new instruments and repair existing systems. The successful mission extended the observatory's operational life and significantly enhanced its scientific capabilities for years to come.

Mission overview

STS-125 was a NASA mission flown by the Space Shuttle Atlantis, representing the fifth and final servicing mission to the iconic Hubble Space Telescope. Originally scheduled for 2008, the launch was delayed following the Space Shuttle Columbia disaster to allow for the development of enhanced safety procedures and a standby rescue mission, designated STS-400. The flight was directed from the Johnson Space Center in Houston, with primary payload operations managed from the Goddard Space Flight Center in Maryland. The mission's primary objective was to perform critical upgrades and repairs that would ensure Hubble's functionality through the next decade.

Crew

The flight was commanded by Scott Altman, a veteran of three previous shuttle missions. The pilot was Gregory C. Johnson, while the mission specialists were a seasoned team: Michael Massimino, Michael Good, Andrew Feustel, John Grunsfeld, and Megan McArthur. Grunsfeld, an astrophysicist, was making his third visit to Hubble, earning the nickname "Hubble Repairman." McArthur served as the flight engineer and primary robotic arm operator, responsible for the intricate maneuvers of the Canadarm to capture and deploy the telescope.

Mission highlights

After launching from Kennedy Space Center, the crew immediately began preparing their tools for the rendezvous with Hubble. Using the shuttle's robotic arm, McArthur successfully captured the free-flying telescope and secured it onto a servicing platform in Atlantis's payload bay. The mission faced a significant hurdle when a handrail on the telescope proved difficult to remove, requiring an improvised tool and extra effort by spacewalkers Massimino and Good. Despite this and other minor issues, all primary mission objectives were completed, including the installation of new science instruments and the replacement of aging components like gyroscopes and batteries.

Hubble Space Telescope servicing

The servicing work transformed Hubble into a more powerful observatory. Astronauts installed two new instruments: the Wide Field Camera 3, which sees in ultraviolet, visible, and near-infrared light, and the Cosmic Origins Spectrograph, designed to study the large-scale structure of the universe. They also performed the delicate repair of the Space Telescope Imaging Spectrograph and the Advanced Camera for Surveys, both of which had suffered power failures. This work effectively gave Hubble a complete set of new, state-of-the-art instruments, vastly improving its discovery potential.

Spacewalks

The mission featured five consecutive days of extravehicular activity, totaling over 37 hours. The spacewalking teams, consisting of Grunsfeld and Feustel on three spacewalks and Massimino and Good on two, executed a meticulously planned sequence of tasks. Key activities included the removal of old instruments, the installation of new ones, the replacement of all six NiMH batteries, the installation of new fine guidance sensors, and the addition of a new outer blanket layer for thermal protection. The repair of the spectrographs involved unprecedented in-orbit surgery to access and replace delicate circuit boards.

Landing and legacy

Due to unfavorable weather at the primary landing site in Florida, Atlantis landed at Edwards Air Force Base in California on May 24, 2009. The mission was hailed as an unqualified success, having overcome numerous technical challenges. The upgrades performed by STS-125 extended Hubble's operational life well into the 2020s, enabling groundbreaking discoveries in fields like dark energy and exoplanet atmospheres. The flight demonstrated the peak of human spaceflight servicing capabilities and cemented Hubble's legacy as one of the most important scientific instruments in history. Category:Space Shuttle missions Category:2009 in spaceflight Category:Hubble Space Telescope