Questions tagged [optical]
The optical tag has no usage guidance.
34
questions
1
vote
1answer
47 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
434 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
139 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 ...
2
votes
1answer
82 views
Are new precision gyroscopes used in spaceflight pretty much all optical?
Gyroscopes are used in spaceflight as parts of inertial systems to monitor spacecraft attitude. They are not absolute, they will drift slowly over time and so need occasional calibration via other ...
4
votes
0answers
72 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 ...
3
votes
0answers
149 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 ...
0
votes
0answers
13 views
How exactly is asteroid composition determined using spectral data from key regions not observable through Earth’s atmosphere?
@LocalFluff's answer to the question How does one spacecraft best visit multiple asteroids? mentions the proposed CASTAway Asteroid Spectroscopic Survey mission proposal and links to the conference ...
3
votes
0answers
159 views
Have the Starlink precursor Tintin satellites been talking to each other? If so, how?
Tintin A and B are the first two exploratory and testing spacecraft for SpaceX's Starlink program.
It looks like they are in very similar orbits in both space and time, and are probably that way so ...
1
vote
2answers
188 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
73 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
145 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
59 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
410 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, ...
3
votes
1answer
194 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
vote
1answer
195 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 ...
41
votes
2answers
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 ...
3
votes
1answer
140 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 (...
2
votes
1answer
91 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 (...
3
votes
0answers
240 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 ...
3
votes
2answers
241 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 ...
4
votes
0answers
307 views
All Optical Global Network - how does the space-to-ground link avoid clouds?
I just saw the news item in Lightwave's online website: Laser Light to leverage free-space optics in space for Optical Satellite as a Service.
All Optical Hybrid Global Network (or HALO, as laser ...
3
votes
2answers
586 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 ...
6
votes
2answers
254 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 ...
7
votes
1answer
194 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 ...
4
votes
3answers
218 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 ...
13
votes
1answer
233 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
541 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
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. ...
14
votes
4answers
6k 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
285 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?
10
votes
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 ...
8
votes
1answer
939 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 ...
