ESA retires Herschel space telescope as too hot to handle The European Space Agency has formally retired the Herschel space telescope after nearly four years of operation, and has placed it in a parking orbit that will keep it out of Earth's way. Herschel's at rest at last Herschel's at rest at last Hershcel, along with the Planck space telescope, was launched on May 14, 2009, …
"Hopefully by then we'll have the space-faring capability to retrieve it and bring it home to take its well-earned place in a museum or suitable institute of learning."
I wish we could do that for Hubble, it's going to wind up a molten streak across some ocean floor. Not a very diginified way to go for something that has expanded out horizon so immensely.
It's a fair point, but it's one that was considered. Essentially, big as a 3.5m mirror is, it isn't *that* big. With the dawn of mega-scale distributed telescopes and interferometry here on terra firma, an uncooled 3.5m instrument wouldn't actually be of much use, even with the advantage of being in space. You'd end up in the situation where you'd compromise the lifespan or the capabilities of the primary mission for a secondary mission that could well be obsolete before it even came online. Even if the far infrared performance of ground-based telescopes doesn't come up to what we might hope for, you'd end up with a poor man's JWST.
When they designed Herschel they basically went "Right, so, Ariane 5's about 5 metres across, lose a bit over a metre for the heatshield, then let's fill the rest up with the BIGGEST MIRROR and BIGGEST TANK OF HELIUM we can build" - more instruments or less helium would've compromised that.
It's the biggest mirror outside the atmosphere[1] by a long way, as far as I can recall which gives it an advantage in the infra-red imaging spectrum, and it actually got built and launched and used. The JWST seems to have grown roots and its launch and commissioning is receding deep into the future almost as fast as the universe is expanding...
I'm envisaging the Herschel could have carried an additional lower-resolution detector operating in the near IR, cooled by a heat-pump and used for recording time-series IR data of dynamic changes in nebulae etc. over a period of years or even (if the money and hardware held out) decades. The Hubble has been kept running for nearly thirty years now after a lot of teething-trouble TLC and it still has a few more years left under the hood so I'd expect the Herschel's "bus" with its more modern hardware to be able to match that to support an extended scientific program if the detectors were available.
[1] I think there's a radiotelescope satellite that's got a bigger collecting dish but it's not optical.
Sorry my excuse is I wasn't paying attention and I'd looked up 'Lagrangian points' which the Herschel uses and ended up at NASA:
http://map.gsfc.nasa.gov/mission/observatory_l2.html
Very interesting and understandable article. I'm in the UK so don't blame our American cousins this time!
Anyway congratulations ESA.
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