Linked Questions

14 votes
4 answers
7k views

How can electronics on board JWST survive the low operating temperature while it's difficult to survive lunar nights?

Compared to the temperatures encountered in lunar nights, the desired operating temperature of the James Webb Space Telescope is very low. Lunar nights are typically -170°C while the operating ...
karthikeyan's user avatar
  • 4,469
22 votes
5 answers
6k views

Why are eclipses of the James Webb by the Earth or Moon not permitted during the mission?

Why are eclipses of the James Webb Space Telescope (JWT) by the Earth or Moon not permitted during the mission? In Seasonal variations of the James Webb Space Telescope orbital dynamics it is stated ...
Woody's user avatar
  • 21.6k
14 votes
4 answers
4k views

Why aren't space telescopes put in GEO?

I don't know of any space telescope that has been placed in geosynchronous orbit among the communication satellites. I wonder why not? In GEO, a space telescope could use a single stationary radio ...
LocalFluff's user avatar
20 votes
4 answers
3k views

Why are JWST optics not enclosed like HST?

The Hubble Space Telescope encloses its primary and secondary mirrors in a tube. The James Webb Space Telescope has no tube around its optics, which obviously leads to significant mass savings. Does ...
gandalf61's user avatar
  • 1,421
17 votes
4 answers
5k views

Could JWST stay at L2 "forever"?

Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST ...
user avatar
18 votes
2 answers
2k views

Is this what station keeping maneuvers look like, or just glitches in data? (SOHO via Horizons)

I've been enjoying the JPL Horizons web interface and after I discovered the incredibly extensive database associated with SOHO (Solar and Heliospheric Observatory, also see sohowww.nascom.nasa.gov) ...
uhoh's user avatar
  • 149k
10 votes
2 answers
3k views

The design of the halo orbit of the James Webb Space Telescope

As I feel a little less uncomfortable with "halo" orbits, with this question, I would like to explore the practical aspects, in particular those related to the design of the James Webb Space ...
Ng Ph's user avatar
  • 2,724
13 votes
1 answer
1k views

What is the principle behind Mariner 4's "Solar Pressure Vanes"? In what case(s) would they be effective?

The image below, found in this answer shows four "Solar Pressure Vanes" on Mariner 4. I've never heard of such a thing. I can imagine that it might have been thought to help favor the spacecraft's ...
uhoh's user avatar
  • 149k
3 votes
1 answer
156 views

How would 2 spacecraft be launched to be in sync in opposite directions?

How would 1 spacecraft be launched to have a prograde orbit and the another be launched retrograde to have a mirrored orbital path around the sun or otherwise? Would the 2 spacecraft launch together ...
Muze's user avatar
  • 1
1 vote
1 answer
178 views

How would 2 JWSTs make stereo pictures?

Could 2 JWST be launched in opposite directions to provide stereo vision? Would a stereo picture provide any benefit? https://space.stackexchange.com/a/35402/18879 Related: How will JWST manage ...
Muze's user avatar
  • 1
1 vote
1 answer
107 views

Shape Memory Metal Self Stablizing Solar Sail

Can the frame of a solar sail be made with shape-memory metals to contract in a way to maintain orientation to the Sun either in orbit or interplanetary? Would there be enough temperature difference ...
Muze's user avatar
  • 1
1 vote
0 answers
114 views

How does temperature affect a solar sail?

Is there an ideal temperature which solar sail material operates at? Does a colder reflective surface create more thrust? Related: How will JWST manage solar pressure effects to maintain attitude and ...
Muze's user avatar
  • 1