Questions tagged [hubble]

The Hubble Space Telescope (HST) is a space telescope in low Earth orbit with a 2.4 meter main mirror capable of observing near ultraviolet, visible, and near infrared light. It was launched in 1990 and remains in operation (following five servicing missions) as of 2015.

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17
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3answers
3k views

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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How is the Hubble main mirror protected from debris?

The Hubble Space Telescope recently hit 25 years in space. It orbits at ~550 km altitude (limited by the altitude the shuttle could reach to service it) and has sustained minor/trivial exterior ...
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Why did the frequency of TLEs for the Hubble Space Telescope drop by a factor of 3 in 2009?

I noticed that the TLEs for the Hubble Space Telescope (HST) are posted almost twice a day. Then I looked back in time and saw that this rate varies quite a lot! The plot shows the time interval ...
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451 views

Hubble's one-gyro mode; how does it work for attitude control, stabilization, and slewing?

Space.com's Hubble Space Telescope Apparently in 'Safe Mode' After Gyroscope Failure says: "It’s true. Very stressful weekend. Right now HST is in safe mode while we figure out what to do. ...
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Would it have been cheaper and/or faster to put a James Webb-like Space Telescope on a balloon instead of a rocket?

I've just noticed the following items: CNET: NASA to send stadium-size balloon skyward to study the cosmos JPL/NASA News: NASA Mission Will Study the Cosmos With a Stratospheric Balloon Even in 2020 ...
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What were the relative orientations of the Hubble Space Telescope's three star cameras, six rate gyros and four reaction wheels optimized for exactly?

Table 3. in paper Hubble Space Telescope Reduced-Gyro Control Law Design, Implementation and On-Orbit Performance; AAS 08-278 found in @OrganicMarble's answer seems to give the unit vectors where the ...
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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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760 views

Hubble gained weight while in space; Which components account for this extra mass?

NASA lists hubbles masses: At launch: 11,110 kg After the last service mission: 12,247kg. That's a 1137 kg increase, about 10%! Which parts are responsible for this increase ? And is there a ...
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What were Hubble's jerk and jounce limits? Did JWST have the same?

From Wikipedia: In physics, jerk is the rate of change of acceleration; that is, the derivative of acceleration with respect to time, and as such the second derivative of velocity, or the third ...
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Why do these two Hubble Space Telescope star cameras point in nearly the same direction, and what's the other window for?

The article in Forbes Former Astronauts Share Ways To Cope With Social Distancing & Isolation includes the following image of the Hubble Space Telescope. Question: I believe that those three ...
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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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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 ...
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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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Could Hubble observe the night side of the Moon?

IIUC the Hubble space telescope cannot observe the Sun lit side of the Moon. And Hubble is never pointed closer than 90 degrees towards the Sun. But this still allows for observing the night side of ...
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If we used Hubble, or the James Webb Space Telescope, how good image could we get of the Starman?

I know that this is never going to happen, because those telescopes have much more important things to look for ... But I was just wondering if we still did it, what would the best result look like? ...
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Why is there a lid on the Hubble Space Telescope?

What is the lid on the Hubble Space Telescope for?
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Does Hubble need to dump momentum of its reaction wheels?

Hubble has no thrusters, but it is large enough to have nontrivial gravity gradient and tidal forces acting on it. This would induce a torque that has to be cancelled by its reaction wheels. If I ...
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Has Hubble ever focused on something close enough that it had to move away from being focused at infinity?

Hubble wouldn't have to change focus for Pranksat to work because Pranksat is cleverly designed to present a virtual image with a focus at infinity. But if the diffraction-limited Hubble wanted to ...