NASA and ESA celebrated the 20th anniversary of the installation of the Hubble Space Telescope’s ACS (Advanced Camera for Surveys) instrument with the publication of some images among the more than 125,000 captured during these twenty years of service. On March 7, 2002, astronauts James Newman and Mike Massimino installed the ACS during the space shuttle Columbia’s STS-109 mission. This instrument made a significant contribution to a lot of extraordinary astronomical research conducted using Hubble.
In 2002, the Hubble Space Telescope was already a highly regarded astronomical instrument because it had already contributed to many astronomical discoveries after being put into orbit on April 25, 1990. During the first decade of operation, the first service missions were conducted to correct a problem with the primary mirror and install new tools.
The Servicing Mission 3B was accomplished with a spacewalk over the course of the space shuttle Columbia’s STS-109 mission. It made it possible to replace FOC (Faint Object Camera), one of the original instruments, with ACS, whose sensitivity extends from ultraviolet to near-infrared.
A fault of the ACS instrument in January 2007 rendered the two channels most commonly used in scientific operations inoperable. The Servicing Mission 4, accomplished on May 16, 2009, with a spacewalk during the space shuttle Atlantis’s STS-125 mission, allowed astronauts Andrew Feustel and John Grunsfeld to repair the Wide Field Channel, used for 70% of the previous scientific operations.
Over the course of twenty years, the ACS instrument has been used for a series of observations of many very different objects. Planets and other objects in the solar system are the closest studied thanks to ACS to go to increasingly distant objects such as stars and exoplanets in the Milky Way, galaxies at various distances to reach the limits of its possibilities with primordial galaxies over 10 billion light-years away.
The James Webb Space Telescope was finally launched on December 25, 2021, but Hubble continues to be a very important astronomical instrument and the ACS instrument remains crucial for astronomers. There are plans for possible new servicing missions that could extend Hubble’s life again but a new mission would pose a challenge because it would need to be rethought compared to the ones conducted using space shuttles. At this moment, it’s difficult to understand the future of Hubble but NASA and ESA have every reason to celebrate the 20th anniversary of the installation of the ACS instrument for all the contributions it is still offering to astronomy.
