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About six months. https://webbtelescope.org/quick-facts/mission-launch-quick-facts https://webbtelescope.org/quick-facts/mission-launch-quick-f... > After rea

by shagie 5y ago

About six months. https://webbtelescope.org/quick-facts/mission-launch-quick-facts https://webbtelescope.org/quick-facts/mission-launch-quick-f... > After reaching its orbit, Webb undergoes science and calibration testing. Then, regular science operations and images will begin to arrive, approximately six months after launch. However, it is normal to also take a series of "first light" images that may arrive slightly earlier. It will take about a month for it to get out to the Sun-Earth L2 point which is 1.5M km (0.01 AU) from the Earth. For comparison, the Moon is 384k km away. The telescope will be 4x further away from the Earth than the Moon is.

monocasa 5y ago
We'll probably get the calibration images before the six months from now when regular science missions start if they go according to plan as it's great press. Also there's a chance that there's a delay on the science mission images to allow for academic publishing.
shagie 5y ago
(and too late for an edit) that 1.5M km thing is moderately important when it comes to communication with the JWST. The frequencies that can be used for communicating with a satellite or space probe are governed by how far away it is. The cut off for this is 2.0M km. https://en.wikipedia.org/wiki/Deep_space_bands https://en.wikipedia.org/wiki/Deep_space_bands And so, the JWST is still considered near earth and can't use the deep space bands. https://deepspace.jpl.nasa.gov/dsndocs/810-005/201/201C.pdf https://deepspace.jpl.nasa.gov/dsndocs/810-005/201/201C.pdf
- naikrovek 5y ago
  why is the exact frequency used important? what's different about near space bands versus deep space? they look arbitrary to my idiot eyes. (I'm asking why the band used is significant in any way)
  - dn3500 5y ago
    It's not a technical restriction, it's a regulatory one. Like how parts of the UHF spectrum are allocated to TV and parts to radio. They don't want near earth communication going on in the deep space band because it will swamp the weaker signal.
    - naikrovek 5y ago
      right but the bands are not far apart, and the comment I originally replied to seemed to imply that there was significance that it was in the near space category rather than deep space. like it enabled something or was important in some unmentioned way. it was the whole (unspoken) point of the comment and I'm not "in the know" enough to already know the unspoken part. I'm asking what the unspoken part is.
      - jessaustin 5y ago
        According to the wiki link above, the bands are similarly sized and adjacent, so this wouldn't have much to do with "physics". Perhaps the "near" bands are just more congested?

by shagie 5y ago

monocasa 5y ago

We'll probably get the calibration images before the six months from now when regular science missions start if they go according to plan as it's great press. Also there's a chance that there's a delay on the science mission images to allow for academic publishing.

shagie 5y ago

(and too late for an edit) that 1.5M km thing is moderately important when it comes to communication with the JWST. The frequencies that can be used for communicating with a satellite or space probe are governed by how far away it is. The cut off for this is 2.0M km. https://en.wikipedia.org/wiki/Deep_space_bands https://en.wikipedia.org/wiki/Deep_space_bands And so, the JWST is still considered near earth and can't use the deep space bands. https://deepspace.jpl.nasa.gov/dsndocs/810-005/201/201C.pdf https://deepspace.jpl.nasa.gov/dsndocs/810-005/201/201C.pdf

naikrovek 5y ago
why is the exact frequency used important? what's different about near space bands versus deep space? they look arbitrary to my idiot eyes. (I'm asking why the band used is significant in any way)
- dn3500 5y ago
  It's not a technical restriction, it's a regulatory one. Like how parts of the UHF spectrum are allocated to TV and parts to radio. They don't want near earth communication going on in the deep space band because it will swamp the weaker signal.
  - naikrovek 5y ago
    right but the bands are not far apart, and the comment I originally replied to seemed to imply that there was significance that it was in the near space category rather than deep space. like it enabled something or was important in some unmentioned way. it was the whole (unspoken) point of the comment and I'm not "in the know" enough to already know the unspoken part. I'm asking what the unspoken part is.
    - jessaustin 5y ago
      According to the wiki link above, the bands are similarly sized and adjacent, so this wouldn't have much to do with "physics". Perhaps the "near" bands are just more congested?