Servicing Mission 3B
On 1 March 2002 11:22 CET the Space Shuttle was launched for the fourth visit of the NASA/ESA Space Telescope. During this second part of the third servicing mission (dubbed SM3B) - one of a regular programme of upgrades and maintenance - the seven astronauts aboard the Space Shuttle Columbia worked on the telescope in the course of five scheduled spacewalks.
Although Hubble has many redundant components and safety systems intended to cope with unexpected situations, such a complex and technologically advanced spacecraft cannot be designed to handle all eventualities that might occur during its expected record 20-year lifetime. Servicing missions carried out by Space Shuttle astronauts are vital to keep Hubble in peak operating condition and ready to deliver world-class observations.
Right from the very beginning, Hubble was intended to be modular and astronaut-friendly. It is the first space observatory designed for routine maintenance, upgrade and refurbishment in orbit.
The primary tasks for the Servicing Missions were:
- Upgrading science instruments to exploit technological advances
- Replacing components that have deteriorated (due to the large temperature changes in space, radiation, etc.)
- Replacing equipment which has failed or malfunctioned
Originally planned as one mission, the third Servicing Mission (SM3) was split into two parts (SM3A and SM3B) because of the sheer number of tasks to be carried out and the urgency with which the gyroscopes had to be replaced in late 1999. Furthermore, some of the hardware initially planned for Servicing Mission 3 was not ready in time for the first flight, and so could conveniently be rescheduled to the later Servicing Mission 3B.
Servicing Mission 3A, in December 1999, accomplished several important objectives. The new, improved and upgraded equipment included six fresh gyroscopes, six battery voltage/temperature improvement kits, a faster, more powerful main computer, a next-generation solid state data recorder, a new transmitter, an enhanced fine guidance sensor and new insulation.
In Servicing Mission 3B astronauts coped with many novel and challenging tasks and, during extensive spacewalks, worked hard upgrading the instruments for a renewed Hubble ready to work on well into the new millennium.
The assignments for Servicing Mission 3B included:
- ACS - A new digital camera to extend Hubble's vision
- New solar panels
- Replacement of the Power Control Unit
- Nicmos returns!
- A new coat for the telescope
- A little boost
See also "Assignments for Servicing Mission 3B" for more details.
Hubble was released from the Shuttle 9 March 9:32 CET.