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For ESA's Herschel Mission, the End Is Near
Trapezium Artist writes "The European Space Agency's far-infrared space observatory, Herschel, will soon run out of its liquid helium coolant, ending observations after more than three years of highly successful scientific operations. Predictions by ESA engineers are that Herschel will run out of helium later in March, at which point its instruments will warm up,
rendering them effectively blind. Herschel was launched in 2009 along with ESA's Planck satellite to the Sun-Earth L2 point, roughly 1.5 million kilometers from Earth. At that location, the Sun and Earth remain along a more or less constant vector with respect to a spacecraft, meaning that it can cool to very low temperatures behind a sunshield. At such a large distance from Earth, however, there is no way of replenishing the coolant, and Herschel will be pushed off the L2 point to spend its retirement in a normal heliocentric orbit. With the largest monolithic mirror ever flown in space at 3.5 meters diameter and three powerful scientific instruments, Herschel has made exciting discoveries about the cool Universe, ranging from dusty starburst galaxies at high redshifts to star-forming regions spread throughout the Milky Way and proto-planetary disks of gas and dust swirling around nearby young stars. And with an archive full of data, much of it already public, Herschel is set to produce new results for years to come."
"dusty starburst galaxies"
Did anyone else misread the headline as ESA Hershey Mission
is it going to run out of coolant in march and be "rendered blind" or is it going to produce new results for years to come"
when you lose spacecraft because they run out of consumables. What could we have learned if we'd had continuous IR coverage since the launch of IRAS in 1983, instead of a couple of missions each 1-3 years long?
You know you're primitive when you find that it's (much) cheaper to replace said spacecraft than to resupply them. When we find that it's economical to send out a tanker full of cryogens, then we will truly be an interplanetary species. Not holding my breath. (Bear in mind that Herschel is out at L2, not in Earth orbit.)
Sorry, maybe a stupid question but why is it difficult to cool something in space which has a temperature of near absolut zero? couldn't you just run something through a pipe in the shade of yourself?
Given the amount of effort it takes to put something up there, wouldn't it make more sense to replace aging equipment with new and improved equipment rather than go to the trouble of resupplying the old?
They already predicted that we will run out of helium, Herschel is just the beginning.
No balloon for you!
It's no different than any other remote site science expedition. Great effort is made to ensure that Antarctic stations are supplied with consumables, oceanographic vessels come home when then they run low/out, etc... etc... Even fixed installations like LHC have ongoing logistics needs, like an on-site cryogenic plant to ensure a steady flow.
Logistics (and it's handmaiden, maintenance) are something all scientific equipment needs to deal with. Space isn't special.
space is cold?
I seems to me that NASA has all the technology needed to create a spacecraft, manned or unmanned, to make accessing the local solar system (Earth, moon, etc.) a matter of routine. Perhaps if they had an appropriation that lasted for more than a year and they (Administration, Congress, NASA) stopped canceling things when they reach 75%-80% completion.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
OK, everyone knows space is big but doesn't this seem a bit cavalier, leaving old space junk in orbit?
It's orbit around the sun so there's lots more 'space' for junk to accumulate than say LEO but still. Seems like we're making the same short-sighted decisions over and over.
Can any of the rocket surgeons here comment on what it would take to de-orbit such a device?
'Set the controls for the heart of the sun.' -- Pink Floyd
I understand if it can produce good science in a new orbit, but if it's being moved primarily to avoid cluttering up L2, I think that might be a mistake. Presumably it isn't moving very fast relative to L2, so another craft in L2 orbit should be able to capture it fairly easily. Sooner or later we'll have some kind of station at L2, and Herschel's parts will likely be useful somehow. Will it have sufficient power and good thrusters in 30 years if it's mothballed in place now? Why not wait and move it later if it's determined to be in the way?
Yes, of course! And that's why we do!
But.. if we were more advanced it might not take so much effort to put something up there. That would be a game changer. Rather than throw out spacecraft when their consumables run dry we would do it (or better yet recycle them) when they are technologically obsolete.
Yes, of course! And that's why we do!
But.. if we were more advanced it might not take so much effort to put something up there. That would be a game changer. Rather than throw out spacecraft when their consumables run dry we would do it (or better yet recycle them) when they are technologically obsolete.
Emphasis mine. I doubt it will ever be economically sound - no matter how cheap spaceflight is - to recycle satellites, unless we start making them out of gold. Refueling only makes sense when the total mission cost is less than that of launching a new one. I appreciate your point about the dropping cost of spaceflight but there's a very long way to go; the cost of the actual satellite isn't as large a fraction of the mission cost as one might think.
In span of time between missions, there is usually incredible progress in a few key parameters, detector noise, spacial resolution, and frequency range. While you can argue that a "refueled" IRAS could beat down the noise by observing for years and years, changing out detectors and telescopes is effectively launching a new mission. Also, as our knowledge of astrophysics grows, we design missions to answer the unanswered questions. 10 years of IRAS is not necessarily as interesting as a couple of years of a significantly more advanced mission.
I have no technical knowledge of the Herschel telescope, but it seems a mirror like that should be useful, for example, at visible wavelengths without the cooling the helium provided. I guess it would require different detectors or some other technical modification that can't be performed remotely, so... Oh well.
Often when the projects are 75%-80% from completion, they are already 200%-500% over budget. Poster child -- JWST. Poster child #2 -- Constellation, though it didn't get close to 75% completion. How far do you let a rogue one go before you pull the plug as it eats up the funding for the other, possibly better managed, projects?
So instead of fixing the project, you kill it, waste all that money and have nothing?
If I'm building a house and it's over budget, I do what I can to get it finished. At least then I have a house to live in.
Was the Constellation project really broke?
How much money do you flush down the toilet instead of seeing it through and having a product?
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
What about the mirror, which is relatively large?