Hubble is the first large optical telescope to be placed in space (miles higher than any mountaintop observatory). Having this powerful telescope in space is so advantageous because its view is not obscured by atmospheric distortion, cloud cover or the bright lights of our cities. Since the space shuttle Discovery carried Hubble into space in 1990, the telescope has been used to observe distant stars and galaxies as well as the planets of our own solar system.
* Service Mission 4 (SM4) *
Just like any 2.5 billion dollar piece of equipment, Hubble requires maintenance and can be enhanced with upgrades; so astronauts regularly service the telescope while it remains in orbit. Service Mission 4 was originally scheduled to take place back in 2004, but was postponed after the 2003 Columbia Space Shuttle tragedy.
Atlantis just completed is SM4 mission, the fifth and what they say is the last time. On the agenda were five spacewalks in which the astronauts installed new instruments, repaired old instruments that were on the fritz, and replaced components; all of which should keep the telescope functioning for at least the next five years.
* Calendar of Service Mission 4 Main Activities *
* May 11, 2009 Day 1: Launch of Space Shuttle Atlantis
* May 12, Day 2: Ground control at the Space Telescope Operations Control Center remotely reconfigured some of the instruments on the telescope and adjusted the shuttle pointing system.
* May 13, Day 3: Space Shuttle Atlantis captures Hubble Space Telescope. All didn’t go as planned, but objectives were met with alternate plans.
* May 14, Day 4: First spacewalk – 7 hours 20 minutes. A new science instrument and a new command and data handling unit were installed.
* May 15, Day 5: Second spacewalk – 7 hours and 56 minutes. A new science instrument, new command and data handling unit and six new gyros were installed.
* May 16, Day 6: Third spacewalk – 6 hours and 36 minutes. Another new science instrument was added and an unscheduled on-orbit repair was made on an under-performing camera.
* May 17, Day 7: The fourth spacewalk was the sixth longest in US history, spanning 8 hours, 2 minutes. Part of the long walk was due to trouble with removing a handrail. The delay pushed back some additional work that had been scheduled that day.
* May 18, Day 8: Fifth, and final, spacewalk – 7 hours, 2 minutes. A battery group replacement was installed. Fine Guidance Sensors and three thermal blankets protecting Hubble’s electronics were replaced.
* May 19, Day 9: Space shuttle separated from Hubble telescope.
* Space Shuttle Atlantis Returning Home *
The astronauts are now returning home to Kennedy Space Center after what will be an 11-day mission. The first opportunity for the shuttle to land was assessed as 10:01 EDT on May 22, but it does not look as if the weather will cooperate. Landing will most likely be delayed. See the STS-125 landing blog for updates.
* Links to More Information on Service Mission 4 *
There are several fantastic SM4 links on the NASA website. See the following to learn more about the latest mission to Hubble:
Service Mission 4 Essentials: Information on the latest Hubble mission.
Service Mission 4 Multimedia: Variety of videos and images visitors can select from.