Hubble's Last Bow

This is the last photo taken of the HST from Atlantis as the last shuttle maintenance visit withdrew.

 

Hubble is, by design, in a high-drag orbit in the upper atmosphere. It's orbit decays naturally and it was designed so that each shuttle mission would need to boost it up to a higher orbit. The prior service missions all did that, but since Hubble's life is about over, the last visit by Atlantis did not. Hubble's orbit will gradually decay until sometime between 2019 and 2032 (depending on many factors) when drag will drop it into the upper atmosphere completely and a rapid re-entry will begin.

 

The HST was originally designed to be brought back to Earth by a shuttle mission at the end of its life and retire at the Smithsonian but the telescope was four years late going up (due to the Challenger disaster) and it lived so long that the original plan is no longer possible (obviously).

 

Most of Hubble will burn up on re-entry, but calculations have shown that some components such as the glass main mirror and several large pieces of the support structure will survive the trip down. These will rocket to Earth at high speed with the possibility for damage and/or death (NASA has calculated a 1 in 700 chance of fatalities occurring given a completely uncontrolled re-entry). Controlling drag on the Hubble is possible through the use of the gyros aboard, and Atlantis did replace those. All six of them. So the actual re-entry will likely be semi-controlled, the telescope will be gently guided towards a remote ocean re-entry. That glorious and troubled main mirror that first disappointed us and then turned around and showed us the universe will end up at the bottom of the Pacific Ocean.

 

This is another beautiful machine that has far outperformed it's mission. We got our money's worth and more from this guy.