Tonight’s Nova program hilighted NASA’s repair of the Hubble Telescope. Quite a feat. Apparently this was a one-time-only repair and it will never be touched by human hands again. So, what will eventually happen to it. Will the environment in space keep it physically intact, although not functioning? Will it remain in its same orbit? Eventually re-enter earth’s atmosphere?
Not sure how reliable this is but deorbiting it makes the most sense. According to the page linked below this will happen anywhere from 2013-2021.
If we do nothing, atmospheric drag will eventually slow it down until it falls back to earth. Current plans are to either send up a mission to retrieve it at some later date, or attach a de-orbiting module to control its reentry so any surviving parts of it don’t crash anywhere too dangerous.
I sort of suspect that in the back of the minds of some of the NASA engineers is the idea that if Hubble was still functioning and it’s orbit started to degrade enough to worry, that the same deorbit capability could be used to allow a robotic reboost mission. Not trivial - and making sure that rocket plumes don’t degrade the optics whilst boosting make it harder. Maybe a nice ion booster.
This presupposes that Hubble would still be working well enough to warrant it - it isn’t free to keep it running. The science outcomes need to justify the ground support costs. Eventually they won’t.
Not all that hard, actually. The orbital dynamics are simple enough to do by hand, and the thing about rocket plumes is that they go away from the spacecraft.
And while there will eventually come a point where the costs of running Hubble exceed the value of the data obtained from it, that point wouldn’t come until at least a year or so after the Webb telescope is launched (cross-calibration would itself be a valid justification), and probably not for decades after that point (the two instruments work in different wavelength bands, so even after the Webb launches, the Hubble will still be the best there is at what it does).
We no longer have the ability to return Hubble to the ground intact, even if we decided to prolong the shuttle programs. Due to differences in cargo bay design between the shuttles, Columbia was the last shuttle capable of carrying Hubble in its cargo bay. The more recent shuttles (Atlantis, Discovery, Endeavor) have a different airlock design which protrudes into the cargo bay enough to make it impossible to carry the Hubble.
It will be de-orbited and ground to dust, and this dust will be sold as an exotic spice to bars, who will offer “Hubble cocktails”. They will be expensive and when you drink them, everything will look blurry.
Rats, I was kind of hoping that the space between Earth and it would be expanding.
Sorry, that gave me visions of it coming down someplace like Bogata or Mogadishu.
I always thought that none of the Shuttles could safely re-enter, glide, and land with something that heavy in their cargo bays’. The damn things have the aerodynamics of a brick when they’re empty!
If we do nothing else and never touch it again, about how long until it falls on its own?
OK, thanks. Hope we’ll be able to get some more good use out of it.
We’re continually getting good use out of it. If we had a half-dozen different Hubbles, we’d be getting good use out of all of them. Most of it doesn’t make the news, but there’s a long waiting list and a tough selection process to get observing time on the Hubble.
They’ve brought back recovered satellites from orbit before. STS-51-A in 1984 brought back two communication satellites that had failed after being launched by a previous Shuttle mission. However, Hubble is a good deal bigger than those two satellites combined, I’m fairly certain.
My understanding is that Hubble is about the size/weight of a school bus.
Well, yes and no. The net momentum of the plume does certainly go away from the spacecraft, and in absence of atmosphere there is no recirculation or entrainment of plume, but the plume will also tend to overexpand as it is generally prohibitive to make a nozzle large enough to obtain contained expansion. This means that you’ll have some tenuous part of the plume that can move with a very modest lateral velocity, and if the nozzle is vectoring or the spacecraft is performing a reorientation maneuver, some plume contamination of the delicate optics is possible. It is certainly possible–surveillance satellites very much like Hubble perform orbit mods on a semi-regular basis–but plume direction and the possibility of contamination is considered and simulated.
The payload mass doesn’t really change the aerodynamics very much, and the Shuttle was originally designed to support on-orbit servicing and retreival of satellites, particularly surveillance satellites which dictated the broad delta wing structure to provide sufficient cross-range capability for a once around polar orbit from VAFB. The Shuttle Orbiter has been used to return communications satellites (STS-51-A), experiment payloads such as the European Retrievable Carrier (STS-57), and has carried a number of other captive payloads such as the Spacelab and Spacehab modules and the Wake Shield Facility.
As for Hubble, it has long outlived its original service life. While the four service missions have extended its life (and corrected the infamous optics issue), the fact is that a new telescope using modern sensors and data processing with much higher bandwidth could be constructed and deployed for less than the cost of two STS missions (and probably more with multiple units being designed and constructed for concurrent deployment). As Chronos notes, there is a phenomenal demand for time–even just a few hours–on Hubble to justify such deployments, and from a scientific standpoint it would be a far better return on investment of scientific knowledge than returning astronauts to the surface of the Moon or Mars, much less mucking about in low orbit. At the current state of the art, it is still cheaper to replace than refurbish.
Stranger
Do a Google search on ‘Shuttle launches from VAFB’ and read what an enormous govt boondoggle that turned out to be. Tens if not hundreds of billions of dollars completely wasted.
I’m a huge supporter of the space program, including manned missions, but the Shuttle was clearly an impractical and woefully inefficient idea not long into its development and should have been abandoned. In fact, the Apollo/Saturn hardware was still a much, much better so-called ‘space truck’ at the time and should have been continued instead. And every engineer knew it!
Given there is a bill before congress to kill funding for completion of the Web Space Telescope, aka Hubble’s replacment, there might be all sorts of hand wringing to come. (This is mostly a political and publicity problem, the WST isn’t a direct replacment in science terms, but has always been marketed as the successor great instrument.)
Some of the recent work with ground based telescopes exceeds Hubble’s basic resolution, but there is much more to the science than high res pictures.
I will guess funding won’t be cut off, but there will be a lot of deal making and lobbying before then. With the last ever flight of a shuttle tomorrow I suspect this is exectly he wrong time to be seen to be slicing away at national preeminance in space science - despite the clear problems that the WST has. Given ESA has a stakeholding in the WST, it may get very messy.
The Webb isn’t a strictly superior instrument to the Hubble, but it’s still fair to call it a successor. Since the time of Hubble’s launch, it’s become clear that there’s more good science to be gotten from an infrared telescope than from visible light or near UV, so they designed the Webb with those wavelengths in mind (in addition to a number of other improvements, like a bigger mirror, of course). So the Hubble is still a little better in the visible, and the Webb can’t do near UV at all, and there’s still some science there, just not as much as in the IR. Ideally, of course, we’d have several space telescopes with Hubble’s range, and several more with Webb’s, and thorough coverage of all the other wavelength bands, too, but everyone knows that’s not going to happen, so we settle for flying the most useful instrument we can, and around when that instrument’s lifespan is ending, launching a new most useful instrument we can.