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"Why doesn't JWST use ion thrusters?" https://space.stackexchange.com/questions/57255/why-doesnt-jwst-use-ion-thrusters https://space.stackexchange.com/questio

• ricardobeat 5y ago
  Yet again, the harsh reality that we are launching two-decades-old designs. Hopefully these timelines seem to be speeding up a bit in the past decade.
• ericbarrett 5y ago
  I have a related question. Would it be feasible to launch a future JWST-style mission into a simple heliocentric orbit, which doesn't require any stationkeeping at all? It will then drift away from Earth over the years, eventually being as distant as L3, before getting closer again. And I appreciate it can be harder to communicate to something that distant. Yet, communications tech has come a long way in the last few years, arguably even farther than stuff like ion thrusters, and I wonder if it wouldn't make more sense to put effort into providing sufficient bandwidth at 2 AU rather than better stationkeeping. Especially if the mission isn't meant to be serviced anyway.
  • p1mrx 5y ago
    It's probably more difficult to design a spacecraft to point at 3 things (earth, sun, target) versus 2 (earth+sun, target).
  • necubi 5y ago
    The main constraint for JWST is that it needs to be able to block all IR radiation from the Sun/Earth/Moon in order to pick out the faint IR signal it's looking for (from red-shifted light from the very early universe). By orbiting L2, it keeps Sun/Earth/Moon all on one side of the spacecraft, which it's then able to block with its sunshield.