Questions tagged [optical]

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5
votes
2answers
519 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 ...
6
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2answers
280 views

How is long-distance optical communications coming along in space?

I remember there was a test of optical communication and some data transfer from lunar orbit to earth, and I think the ISS uploaded (or downloaded-up? which is correct here?) a movie from earth. In ...
3
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0answers
250 views

Could multimode (polymer) optical fiber Gigabit Ethernet be a better choice than WiFi inside future satellites?

In this answer the recent question Are and should satellites use wireless communication internally, rather than cables? it is stated that: This is actually an open research area and despite ...
14
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2answers
352 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
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0answers
225 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
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2answers
197 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 ...
10
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1answer
1k views

Long range laser communication beam divergence angle values?

NASA has been working on demonstrations of laser communication with satellites. The motivation is simple, in that lasers see less power loss because they spread over a smaller angle. That raises the ...
14
votes
1answer
564 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 ...
5
votes
1answer
444 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
161 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 ...
3
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1answer
211 views

Are there plans or a program for an optical relay pathfinder for deep space?

In Glenn Research Center's Richard Reinhart's slides Space Communication and Navigation TestbedCommunications Technology for Exploration for the 2013 ISS Research and Development Conference I saw an ...
1
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1answer
226 views

Yet another OSIRIS! Has the DLR/GOM Space test of the cubesat optical communications link happened yet?

Speaking of "all things OSIRIS" I just ran across the OSIRIS optical communications system for cubesats and smallsats. OSIRIS (Optical Space Infrared Downlink System) highly compact optical ...
36
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5answers
11k 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. ...
4
votes
3answers
241 views

Would plasma sheathes from reentry heating block optical/UV communications as well as radio?

During reentry, it's routine for the ionized atmosphere surrounding the spacecraft to cut off radio communications for a certain period. As far as I know, this can't be avoided, except perhaps by ...
4
votes
1answer
155 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 (...
3
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2answers
257 views

Have amateur satellites ever experimented with optical communications?

I meant to include the more recent amateur satellites such as cubesats, and also amateur radio satellites - where the heritage of amateur satellite building (mostly) has its roots. Have amateur ...
3
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2answers
593 views

Characteristics of the inter-satellite optical link

I'm currently diving into this topic and as I understand from the brief search there are two main types of inter-satellite link: radio and optical. As I can see, one of the main distinction of optical ...
2
votes
1answer
108 views

What GEO relay satellite will the ISS use for end-to-end optical communication with a ground station?

This LEMNOS page on NASA's Explorations and Space Communications site says: The Integrated Laser Communication Relay Demonstration (LCRD) Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (...
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 ...
0
votes
2answers
168 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 ...