Fine Guidance Sensor (HST)
Fine Guidance Sensor (FGS) for the Hubble Space Telescope is a system of three instruments used for pointing the telescope in space, and also for astrometry and its related sciences. To enable aiming the telescope at a specific spot in the sky, each FGS combines optics and electronics. There are three Hubble FGS, and they have been upgraded over the lifetime of the telescope by crewed Space Shuttle missions. The instruments can support pointing of 2 milli-arc seconds. The three FGS are part of the Hubble Space Telescope's Pointing Control System, aka PCS. The FGS function in combination with the Hubble main computer and gyroscopes, with the FGS providing data to the computer as sensors which enables the HST to track astronomical targets.
A Fine Guidance Sensor being refurbished between servicing missions SM3A and SM4
A fine guidance sensors in space on STS Servicing Mission 2 in 1997
STS-125, or HST-SM4, was the fifth and final Space Shuttle mission to the Hubble Space Telescope (HST).
The launch of the Space Shuttle Atlantis occurred on May 11, 2009, at 2:01 pm EDT. Landing occurred on May 24 at 11:39 am EDT, with the mission lasting a total of just under 13 days.
The Hubble Space Telescope in Atlantis' payload bay
From left to right: Massimino, Good, Johnson, Altman, McArthur, Grunsfeld and FeustelSpace Shuttle program← STS-119STS-127 →
Prince Philip of the United Kingdom visited Goddard Space Flight Center in May 2007 and met with the crew of STS-125.
The Cosmic Origins Spectrograph in the cleanroom.
