Questions tagged [optical]

Questions involving optical components, such as lenses, filters, and mirrors

Filter by
Sorted by
Tagged with
5
votes
1answer
219 views

Why is there no microscope on the Mars 2020 rover?

Good magnification microscopes seem both light and cheap. As far as I could find out, there hasn't ever been one on any Mars rovers. The closest I could find is the Mars Hand Lens Imager (MAHLI) which ...
4
votes
1answer
748 views

What is the “space grease” used to lubricate the ISS robotic arm? What are the material considerations for it?

Space.com's Spacesuit Gloves Contaminated During Friday's Historic Spacewalk quotes NASA astronaut Christina Koch (Wikipedia, NASA): "And so," she continued, "of course, a mechanical component like ...
1
vote
1answer
59 views

Why was the central obstruction in Galileo's Solid State Imager (SSI) so large? Was the secondary mirror flat?

According to Wikipedia's Galileo Solid State Imager (SSI) The SSI was an 800-by-800-pixel solid state camera consisting of an array of silicon sensors called a charge-coupled device (CCD). Galileo ...
5
votes
1answer
446 views

What's the largest optical telescope mirror ever put in space?

As a follow-on question to What's the largest optical lens put in space? I'd like to ask about mirrors this time. Question: What's the largest optical telescope mirror ever put in space? Optical ...
4
votes
1answer
166 views

What's the largest optical lens put in space?

While star cameras and wide angle cameras in space are built from glass lenses, large aperture optical systems generally use reflective optics. For some large ones see answers to What's the largest ...
14
votes
2answers
357 views

How fast do optical surfaces get dirty or damaged in space?

These answers: (1, 2) to Do things get dirty in space? mention the Hubble Space Telescope but if I understand correctly refer to the outside of the telescope rather than its optical surfaces. Answers ...
5
votes
0answers
229 views

Why is the Aeolus space laser losing power so quickly?

The BBC News article Aeolus: Wind-mapping space laser is losing power says that Europe's Aeolus satellite was launched last year to gather data to improve weather forecasts, and its observations ...
1
vote
1answer
58 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 ...
1
vote
2answers
199 views

Have optical zoom systems been used in space exploration?

Here, 'optical zoom' means an optical system that changes magnification (angle subtended per pixel). It would not mean for example switching from one camera to another on Hubble, or changing to ...
5
votes
0answers
80 views

What are the space-based optical satellite sensors?

I was looking at a products page for Numerica Corp, and under their product MFAST it said (emphasis mine): Tracks objects in all regimes of space (e.g., LEO, MEO, HEO, GEO) using radar, ground-...
0
votes
2answers
171 views

How does the camera make the exhaust of the Electron's RP-1/LOX exhaust transparent?

In this 20-Nov-2018 Tweet from Rocket Labs XXX Peter Beck there is an image of the nine Rutherford engines of an Electron rocket burning. What is unusual is that the exhaust is luminescent but at the ...
1
vote
1answer
73 views

What optical design is used by the GEDI's receiving telescope and how is the secondary held in place?

GEDI is a sophisticated LIDAR instrument now on its way to the ISS. Once installed, it will use powerful laser pulses (10 mJ, 242 Hz) from several lasers to map height in 3D, collecting multiple ...
5
votes
2answers
543 views

How does the thin gold film in the glass of spacesuit helmets block thermal IR but transmit visible? What's the property?

Comments below this answer suggest that there is a thin gold coating on the glass of spacesuit helmets that blocks thermal IR (say roughly about 10 to 30 microns) but is mostly transparent to visible ...
3
votes
0answers
51 views

What would be the equivalent camera performance specification of Earth-imaging satellites, compared to consumer DLSRs?

In order to better understand what Earth imaging cameras are like (as seen in Google Earth) from the point of view of a photographer, I've asked the following. Consumer-grade cameras like DSLRs, ...
43
votes
3answers
12k views

Is pinging the Moon with a laser as shown on “The Big Bang Theory” possible?

In an episode of season 3 of The Big Bang Theory, the cast sends a laser pulse to the Moon. This seems to be a real thing: What Neil & Buzz left on the Moon (2004). My questions are: Could ...
4
votes
1answer
161 views

Why do the LAGEOS' satellites have four germanium corner cube reflectors out of over 400?

When I was writing this answer about the LAGEOS satellites, I noticed that only four of the over four hundred corner reflectors are made of optical germanium rather than fused silica. Fused silica (...
7
votes
1answer
199 views

How could the laser from Earth to a spacecraft be used other than to propel its light sail?

The Starshot Breakthrough Initiative, sponsored by Yuri Milner, now finances the attempt to use a huge laser on Earth to propell a tiny spacecraft to huge velocity. Not having to carry the energy for ...
13
votes
1answer
244 views

What are the “crossing beams of light” in the Cassini images taken during Enceladus plume flyby?

Whilst checking the latest images of the E-21 flyby returned by the Cassini probe, I've noticed that some of them show interesting optical phenomena that I'm not sure I can explain; For example, on ...
14
votes
1answer
568 views

Accumulated environmental damage to Hubble main mirror

I'm interested in understanding what effect does long-term radiation and microdust exposure would do to the surface roughness of a high-precision mirror like the one on the Hubble. Since it has been ...
36
votes
5answers
12k views

Is photography from a satellite good enough to make out a person on the ground?

When I first saw Google Maps satellite view many years ago, I remember being greatly impressed (and somewhat surprised) with the image quality, considering the photographs came from up there in space. ...
14
votes
4answers
7k views

Was Hubble really related to spy satellites?

Around the launch of the Hubble Space Telescope, I remember comments in the media that the Hubble may be related to certain espionage satellites. The Hubble was designed and built around the time that ...
8
votes
1answer
289 views

What will the new Iranian satellites be imaging?

Iran is soon to launch two satellites which will reportedly take images "with a high degree of accuracy of less than 10 meters" (azernews). What will these satellites be imaging?
8
votes
1answer
978 views

Can you have a rainbow on any bodies in the solar system besides Earth?

We know from Flying on dense atmosphere planets & moons that many bodies in our solar system have sufficient atmosphere for at least the concept of flying to be considered. What about the ...