Questions tagged [space-telescope]

A telescope placed in space, typically for the purpose of avoiding atmospheric distortion, background light, and attenuation of light by the atmosphere.

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Why are so many space telescopes placed in LEO instead of at Lagrange Points? And why do we hear about Hubble more than any Langrange-orbit telescope?

Here is the list of every space telescope launched by different space agencies - List of space telescopes. Most of the listed telescopes are placed in Lower Earth Orbit (about 95% of them). It's ...
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Why should the James Webb Space telescope stay in the unstable L2?

We all know that James Webb Space telescope is planned to be launched in 2018. It has been decided that the orbit of JWST will be elliptical around the Lagrange point L2, which has been declared as ...
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Why is it hard to take a high quality image of far away objects (like Pluto) using a high-tech space telescope?

Why did NASA send a probe so close to Pluto instead of using a high-tech telescope to capture images of its surface? The Icy Mountains of Pluto. Image credit: New Horizons / Johns Hopkins Applied ...
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Could a spy satellite in orbit be recommissioned to do astronomy?

Since the National Reconnaissance Office offered NASA a left-over Hubble sized mirror that might be used for the WFIRST space telescope, I wonder if the NRO has satellites in operation that could do ...
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The JWST - What happens if/when it breaks?

The James Webb Space Telescope (JWST) project could be fantastic, It has the promise of seeing farther than Hubble, almost to the beginning of our space/time. But, orbiting at L2 - while closer by ...
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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 ...
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Would a lunar telescope provide a significant improvement over terrestrial based equipment?

As I understand it, the moon makes for an ideal location for a telescope because it offers environmental factors that are unlike anything achievable on earth: A lack of atmosphere, light pollution, ...
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What's the largest aperture telescope sent beyond the Earth-Moon system?

The question and answer about telescopes sent to different planets got me wondering. There are so many solar system bodies that have been photographed by deep space spacecraft, planets, dwarf planet(s?...
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Are space camera sensors usually round, or square?

A series of round lenses produces a round image on some sort of sensor or sensor array. When it comes to cameras and telescopes out in space, are the sensors also round? It seems like most of the ...
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Why do some space telescopes require cooling (sometimes down to 3K)?

Space is already cold, so why do some space telescopes require cooling? Ex: infra-red telescope What kind of cryocoolers are used, and why?
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Aren't the mirrors of the James Webb Space Telescope too unprotected?

I've looked at the design of the James Webb Space Telescope and I got curious about something, some years ago, it seems that the international space station was hit by micro-meteorites. I'm wondering ...
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JWST observing cherry red Tesla roadster

Assuming both launches are successful, if JWST tries to solve Tesla's cherry red body paint light spectrum, what would it tell about it's composition? Could it be confusing if it was an unknown object?...
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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 ...
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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 ...
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Could we see someone walking on Mars from Earth?

Can any telescope be capable to see some one walking on Mars? How much time dilation would there be? What is the theoretical best resolution?
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What caused the JWST Instrument Radiator temperature to start cooling faster on day 34?

As shown on the temperature plots, the D-Instrument Radiator temperature was slowly dropping after sunshield deployment. Around day 34, however, the temperature started to decrease faster than before....
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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 ...
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Why does the Gaia space telescope have two main mirrors

The Gaia space telescope has two main mirrors that look in different directions, 106⁰ apart. The light of both is focused on a single CCD. Why does it have two main mirrors? Is it only to have more ...
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Why Orion can't be used to service JWST?

Hubble Space Telescope is a marvel of astronomical tools - particularly judging by how much it moved the science. It took a lot of fixes along the way, which certainly prolonged its useful life. Its ...
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Could JWST operate with failed or partial wing mirror deployment?

I have not found any information about contingencies for failed wing mirror deployment. Could JWST operate, and at least partially fulfill its scientific mission, with only the center core mirror, ...
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What are the current state in plans to put a liquid telescope on the moon or in space?

The utility of using liquid metals or ionic salts to automate casting of a telescope mirror could offer a cheap way to build a massive telescope on the moon or in space. The image above, along with ...
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Why did the Herschel Space Telescope need helium coolant?

Inspired by answering this question The Wikipedia entry says this On 29 April 2013, ESA announced that Herschel's supply of liquid helium, used to cool the instruments and detectors on board, had ...
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What was the average temperature of space near the Spitzer Satellite Telescope?

The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003, to be retired in January 2020. The temperature of space near ...
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Why haven't telescopes been sent to other planets?

Why haven't we sent telescopes to other planets? Wouldn't we be able to see further? Aren't we interested in seeing further without having to send a probe that will take years to get to where it's ...
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What are the advantages and disadvantages of sending a telescope into deep space? [closed]

When I first heard of the Voyager missions I thought this: why not do the same, only make it a telescope? I thought it would surely see a lot of things we can't see from Earth or the inner Solar ...
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Interesting diffraction pattern on JWST composite false-color image released today (July 11) at Biden preview - how does this arise?

There was an earlier question on the diffraction pattern in the Mar 16 test image that was mainly explained by the hexagonal shape of the individual mirror segments. Today's image has similar ...
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What might the first deep space telescope using the Sun or Jupiter as a gravitational lens be like?

@SteveLinton's nicely written and sourced answer about using strong gravitational lensing by the Sun or even Jupiter as a kind of telescope to resolve the surfaces of exoplanets is really interesting, ...
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Why the thermal imaging of Mercury's surface requires a telescope on a jet flying through an eclipse?

The NASA News Feature Chasing the Total Solar Eclipse from NASA’s WB-57F Jets describes two telescope-equipped NASA jets that will fly fast enough to spend about 7 minutes in the Umbra (totality) of ...
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How would NASA confirm the James Webb Space Telescope is undamaged after the clamp release incident?

Would NASA point a space telescope at something far enough away in a clean room to confirm that the telescope is functioning correctly before launching it into space? Is there some optical technique ...
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Would an interstellar exoplanet telescope make sense?

Since the transit method of detecting exoplanets requires perfect alignment of orbits, would a Kepler-type telescope yield more exoplanet detections if sent out of our solar system even to relatively ...
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Folding structures in space - What are the potential benefits and problems?

I wonder what the most important potentials and problems are with folding out structures in space. The basic idea is to achieve large structures in space while reducing launch mass and launch volume, ...
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Is it possible to create a geostationary surveillance telescope?

Is it possible to create a telescope in geostationary orbit, with real-time video from any country or area? Some applications could be: Monitoring of burning and deforestation; Residential/industrial ...
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8 votes
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Could the spherical aberration of Hubble have been solved using only software techniques?

When the Hubble space telescope was originally launched, there was a significant error in the way the main lens was ground, causing major spherical aberration. A repair mission was scheduled and the ...
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Why have JWST in a Sun-Earth L2 halo orbit?

What is the main reason JWST will be in a halo orbit around the Sun-Earth L2 LaGrange point? There have been questions on this site that ask Why won't JWST deploy in LEO where it is potentially ...
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Why aren't off-axis reflector telescopes more popular for space telescopes? Have there ever been any?

It seems that: The light gathering capabilities would be slightly better without the blocked aperture (clear aperture is a premium for fairing-limited space telescopes) The diffraction patterns from ...
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How did scientists put forth or create the images of milky way galaxy

I understand telescopes were used to observe and capture images of other galaxies. But, by risking the question sounding pretty ordinary, may I know how did we take the pictures or photographs of our ...
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7 votes
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Can we make super-massive Telescopes to image exoplanets?

This question has already been partly addressed here: When will we have the technology to directly observe an exoplanet with significant clarity? However, my question is focused more on the ...
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7 votes
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What exactly gives a larger field of view to the donated "spy" telescopes that NASA may send to Mars? How much larger?

This answer to Could one of the interstellar probes discover Planet IX by accident? links to Space.com's NASA May Launch Donated Spy Satellite Telescope to Mars which says: An unexpected gift The two ...
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Do crew movements or movement of other objects ever affect space or Earth observation experiments staged on the outside of ISS?

The ISS serves as a platform for both Earth and astronomical observational instrumentation. Do routine movements of the crew or other objects ever cause problems for these observations through ...
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How was the Moon's first telescope used? (Apollo 16)

From Gizmodo's There's Poop on the Moon list of things left on the moon: This gold-plated telescope that was the first tool used to make astronomical observations from the surface of another ...
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Can mirrors be made from fabric?

I was recently listening to a talk about JWST and other future astrophysics missions when the speaker talked about many of the size limitations associated with mirrors etc. I then thought perhaps one ...
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Why would the James Webb Space Telescope need adaptive optics outside the atmosphere?

Adaptive Optics is generally used with ground telescopes to correct for atmospheric distortions or seeing. Right now it is used mostly in the infrared but is starting to be used in longer visible ...
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How would the Apollo telescope have worked in the Apollo command module? Where would it be located and how would it be operated?

In the Vintage Space video episode Missions we Lost When Apollo was Cancelled, there is discussion of the Apollo Telescope and the Block 3 command module after about ...
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What "improvements in technology" allowed the primary mirror of RST (WFIRST) to be less than 1/4 the weight of Hubble's?

The recent NASA press release Primary Mirror for NASA’s Roman Space Telescope Completed states: While it’s the same size as the Hubble Space Telescope’s main mirror, it is less than one-fourth the ...
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Why isn't the JWST mirror bigger?

What's behind the choice of not designing the largest possible folding mirror for the James Webb space telescope, since something like a 13m diameter mirror could also fit in Ariane's fairing?
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What will happen to JWST after its 10 year mission?

JWST launched recently. https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Orbit JWST needs to use propellant to maintain its halo orbit around L2, which provides an upper limit to its designed ...
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Could a 21 meter space telescope detect the nearest exoplanets?

For reference, Hubble's mirror is 2.4 meters wide, the upcoming James Webb's 6.5 meters, and the proposed ATLAST 8 or 16 meters. Let's assume a mirror nearly ten times Hubble's size, 21 meters, is ...
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Curvature of the JWST mirrors

The JWST has four mirrors. The large primary mirror made of 18 hexagonal mirrors The secondary mirror The fixed tertiary mirror The flat fine steering mirror I found very little information about ...
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RIP Kepler, how shall we call your orbit? Does this cyclic flip-flop process have a name?

So long, and thanks for all the Fish Planets The captions in the NASA Ames Research Center video What Will Happen to NASA’s Kepler Spacecraft? read as follows: NASA’s Kepler space telescope found ...
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How do spacecraft reach Lagrange points?

As I understand, to reach a Lagrange point the spacecraft would need to slow down. Also, can spacecraft passing nearby Lagrange points get captured within the point?
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