Is it possible to manage the placement of the telescope mirror in a specific location through the operator, or do we have to randomly view the data reflected to the telescope ?

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    $\begingroup$ Are you asking if the telescope is left uncontrolled and tumbling and we only take random shots? $\endgroup$
    – Polygnome
    Commented May 10, 2020 at 17:40
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    $\begingroup$ space.stackexchange.com/search?q=%5Bhubble%5D+attitude $\endgroup$
    – uhoh
    Commented May 10, 2020 at 18:14
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    $\begingroup$ @Polygnome Well a layperson might assume that the Hubble telescope is simply static in space or static in orbit (so not "uncontrollably tumbling") and because there aren't any visible rockets or jets or ion-drives on the Hubble that it must therefore require some astronauts to physically go out there and manually adjust it by-hand. (In reality it uses Reaction Wheels and Magnetic Torquers - but I imagine most people in the world have no idea how RWs and MTs work because rotational movement without a reaction-mass in-space is not something most people think about, I assume). $\endgroup$
    – Dai
    Commented May 11, 2020 at 4:03
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    $\begingroup$ This is a pretty weak question. Do you really think a billion-dollar project would be left to random chance operation? $\endgroup$ Commented May 11, 2020 at 12:12

1 Answer 1


Yes, Hubble is actively controlled from the ground.

See this NASA page on Hubble Mission Operations

Examples include monitoring and adjusting the spacecraft’s subsystems (e.g., power, thermal, data management, pointing control, etc.), flight software development, sustaining engineering of the control center hardware and software, and systems administration of the network and ground system components.
(Highlight mine)

Images taken with Hubble are carefully planned. The telescope must be pointed in the right direction and hold this attitude for a prolonged time.

Compare for example the Hubble Deep Fields.

The first Deep Field, the Hubble Deep Field North (HDF-N), was observed over 10 consecutive days during Christmas 1995. The resulting image consisted of 342 separate exposures, with a total exposure time of more than 100 hours, compared with typical Hubble exposures of a few hours

The telescope does hold the programmed attitude on its own. A good overview over the way the Hubble holds attitude is given here:

Hubble - Observatory - Pointing Control

Basically, the desired attitude for an image is carefully calculated on the ground. The attitude is then sent up to the telescope, as well as the instruction for what images to take and how long. The telescope then controls itself, rotates to the programmed attitude and takes the pre-programmed shots. It has fail-safes to ensure that it never points at the sun, which could damage the telescope.

  • $\begingroup$ Thank you for your beautiful and complete explanation, for example, can we point it to Mars and see the curiosity of the Curiosity Rover through it ? $\endgroup$
    – Merlin
    Commented May 10, 2020 at 17:59
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    $\begingroup$ That would make a great new question, @Merlin. $\endgroup$ Commented May 10, 2020 at 18:02
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    $\begingroup$ @Merlin No, we can not. We can#t even see stuff left on the moon with Hubble, see this Q&A: space.stackexchange.com/questions/12347/… $\endgroup$
    – Polygnome
    Commented May 10, 2020 at 18:18

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