3 ms·

The article mentions that - "unstable" is not that unstable - small deviations result in a slow drift and can be fixed with small corrections, so with a few thr

The article mentions that - "unstable" is not that unstable - small deviations result in a slow drift and can be fixed with small corrections, so with a few thrusters a craft can stay in place there for years. > Webb will need to conduct occasional small thruster burns for "station keeping" and "momentum management" to retain its proper location and orientation in space. > should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime https://www.space.com/james-webb-space-telescope-fuel-lifetime https://www.space.com/james-webb-space-telescope-fuel-lifeti...

mjevans 5y ago
I wonder what the end of life plan is, just stop correcting and drift about randomly?
- SideburnsOfDoom 5y ago
  I mean, either of us could easily google it, but if we're going to wonder and speculate, it seems more Nasa-like to reserve the last x amount of fuel for a burn that sends it off into deep space to be safely out of the way. Likely won't need much fuel for that.
  - Cthulhu_ 5y ago
    That's what iirc all satellites need to have, a decommissioning plan; IIRC geostationary satellites, when they retire, do a thrust to put them in a (higher?) parking orbit. There was a project and/or company that was looking into building a spacecraft that could make its way to geostationary satellites about to retire, latch onto them (by putting a docking rod into their exhaust for example) and act as its new engine, to extend their lifespans. Which is neat, and even though they may be 20-30 years old, they're still antennas that can transfer data around.
  - thombat 5y ago
    It very much depends upon what "deep space" means to you: * escape from the solar system altogether? That requires a big change in velocity, about half as much again as what it took to get to its current orbit. * chuck it into the sun? needs more change than escaping the solar system * or just a different orbit to the current one with less chance of being inconvenient? then you may as well leave it where it is - there are already a bunch of Earth Trojan asteroids around the Lagrange points which pose a similar likelihood of becoming inconvenient and being much bigger pose a greater hazard.
    - SideburnsOfDoom 5y ago
      > It very much depends upon what "deep space" means to you: In this case "outside of the Earth-moon system" is what I mean. As you say, other changes such as out of solar system or into sun will require massive changes in velocity. In most cases "out of their original Low Earth orbit" is a good definition, but unusually, JWST isn't in LEO to start with. Most satellites can be easily or no-cost de-orbited (chuck it into the earth's atmosphere, allow the orbit to decay until same) from LEO, but with the JWST, I would guess that that would also be expensive.
- ncmncm 5y ago
  It is already a million miles from Earth. It will naturally end up in solar orbit approaching no closer than a million miles away, probably once every other century. So, it really needs no further action.
- egberts1 5y ago
  There is a fuel port in which to recharge should we ever mount such a mission.

mjevans 5y ago

I wonder what the end of life plan is, just stop correcting and drift about randomly?

SideburnsOfDoom 5y ago
I mean, either of us could easily google it, but if we're going to wonder and speculate, it seems more Nasa-like to reserve the last x amount of fuel for a burn that sends it off into deep space to be safely out of the way. Likely won't need much fuel for that.
- Cthulhu_ 5y ago
  That's what iirc all satellites need to have, a decommissioning plan; IIRC geostationary satellites, when they retire, do a thrust to put them in a (higher?) parking orbit. There was a project and/or company that was looking into building a spacecraft that could make its way to geostationary satellites about to retire, latch onto them (by putting a docking rod into their exhaust for example) and act as its new engine, to extend their lifespans. Which is neat, and even though they may be 20-30 years old, they're still antennas that can transfer data around.
- thombat 5y ago
  It very much depends upon what "deep space" means to you: * escape from the solar system altogether? That requires a big change in velocity, about half as much again as what it took to get to its current orbit. * chuck it into the sun? needs more change than escaping the solar system * or just a different orbit to the current one with less chance of being inconvenient? then you may as well leave it where it is - there are already a bunch of Earth Trojan asteroids around the Lagrange points which pose a similar likelihood of becoming inconvenient and being much bigger pose a greater hazard.
  - SideburnsOfDoom 5y ago
    > It very much depends upon what "deep space" means to you: In this case "outside of the Earth-moon system" is what I mean. As you say, other changes such as out of solar system or into sun will require massive changes in velocity. In most cases "out of their original Low Earth orbit" is a good definition, but unusually, JWST isn't in LEO to start with. Most satellites can be easily or no-cost de-orbited (chuck it into the earth's atmosphere, allow the orbit to decay until same) from LEO, but with the JWST, I would guess that that would also be expensive.
ncmncm 5y ago
It is already a million miles from Earth. It will naturally end up in solar orbit approaching no closer than a million miles away, probably once every other century. So, it really needs no further action.
egberts1 5y ago
There is a fuel port in which to recharge should we ever mount such a mission.