Article Posted on : - May 27, 2009

NASA space shuttle Atlantis on runway. A File photo

EDWARDS (BNS): Hubble servicing mission 4 successfully landed back at Edwards Air Force Base in California on Sunday, after replacing four instruments and conducting five successful spacewalks by astronauts.

"This mission highlights what the challenges of spaceflight can bring out in human beings. This mission required the absolute best from the shuttle team, the Hubble science and repair teams, and the crew. The results are a tribute to the entire team and the years of preparation," said Bill Gerstenmaier, associate administrator for Space Operations at NASA Headquarters in Washington in a press release .

Servicing Mission 4 was an intense, 13-day undertaking that revitalised Hubble, making the telescope more capable than ever. All mission objectives were accomplished during five spacewalks that totaled 36 hours, 56 minutes. Hubble's upgrade is expected to extend the iconic telescope's life until 2014.

The Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS) were the two new instruments delivered to Hubble. Both instruments use advanced technology to improve Hubble's potential for discovery dramatically and enable observations of the faint light from young stars and galaxies in the Universe.

Astronauts also repaired the Advanced Camera for Surveys (ACS) and the Space Telescope Imaging Spectrograph (STIS) that were both affected by power failures.

Specialised team of four engineers led by Michael Eiden, ESA HST Project Manager, worked 12-hour shifts to provide 24-hour coverage for the entire mission, supervising the positioning of the telescope's "wings", so as to ensure the safety of spacewalkers and maintain the integrity of the solar array hardware.

"We are elated with the performance of ESA's Solar Array Drive Electronics and Solar Array Drive Mechanisms — they performed flawlessly", said Eiden. "I have worked on all of the servicing missions, but to be able to support the last mission to this extraordinary telescope was particularly gratifying".

The STS-125 mission was the 126th shuttle flight, the 30th for Atlantis and the second of five planned for 2009. Hubble was delivered to space on April 24, 1990, on the STS-31 mission. Atlantis' landing at Edwards was the 53rd shuttle landing to occur at the desert air base.