I am back… about STS-125 the final Service Mission to Hubble
Sorry again for the last 2 weeks. I was in short vacation in Berlin (4 days) and then went to the ESO OPC meeting near Munich. I will go back to that meeting in my future posts. Today I wanted to talk a bit more about the STS-125 which aimed at upgrading the HST. As you know reading my previous posts (here and here) and watching the news, the Atlantis shuttle was launched on May 11 with a crew of astronauts trained to upgrade and fix the Hubble Space Telescope (HST). This complex mission is summarized in this accurate wikipedia web page. On the first Spacewalk, the crew installed a 400-kg new camera called the Wide Field Camera 3, replaced various defective electronic units. On the second spacewalk, the two gyroscopes (needed for the telescope to point and stabilize) were changed. The third spacewalk were dedicated to installed the Cosmic Origins Spectrograph (COS) and repaired the Advance Camera for Survey (ACS). The power supply of the Space Telescope Imaging Spectrograph (STIS) was changed on the forth spacewalk. And finally, the 5th one, the astronauts replaces the battery of the telescope and the Fine Guidance Sensor (FGS) needed to guide during a long exposure.
After 13 days in orbit around Earth, the crew landed safely at the Edwards Air Force Base in California on Sunday May 24. The service mission seems to be a success since HST possesses now 2 new instruments and its life expectation increased by 5 years. President Obama called the crew before landing to congratulate them (see transcript of the conversation here).
Right now both new instruments COS and WFC3 are outgassing, they will be then cool down and tested in the following days. The astronomers and engineers at the Space Telescope Institute will test them, checking if they worked under specifications and were not damaged during the installation. In 10 days, we should see the first lights of COS and WFC3. Some rumors not yet official revealed that the repair of ACS/HRC (the image channel of the instrument) has not been successful unfortunately. Considering that WFC3 will have also imaging capabilities this problem is minor in comparison with the tremendous improvement brought by the Service Mission.
As usual I am attaching a few pictures to this post. The first one (published in APOD on May 25) corresponds to a picture taken by one of the astronauts as the Shuttle was drifting away from HST (credit NASA). The second one taken in the Atlantis shuttle is the traditional in-orbit crew portrait taking during the rest day after the SM4 (credit NASA).The crew had to wait four days before being able to land due to bad weather conditions.