# How does the HST 'aim' or 'steer'? **URL:** \ **Category:** Factual Questions\ **Created:** [August 17, 2007, 4:06pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954 "2007-08-17T16:06:59Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![MrFloppy](https://avatars.discourse-cdn.com/v4/letter/m/43a26b/32.png) [@MrFloppy](https://boards.straightdope.com/u/MrFloppy)\ **Post date:** [August 17, 2007, 4:06pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/1 "2007-08-17T16:06:59Z")
My googling abilities seem somewhat flawed today. I was having a moon landing hoax debunking discussion with a few ill-educated morons on another site and the HST came up. Of course we all know that it should be able to se the Apollo landing sites lol. But anyway I digress. When called to point at a certain part of the sky, how does it manouver? Can it turn in any direction? To any position? Thanks ---
**Author:** ![Bagistan](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@Bagistan](https://boards.straightdope.com/u/Bagistan)\ **Post date:** [August 17, 2007, 4:34pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/2 "2007-08-17T16:34:11Z")
The _Hubble Space Telescope_ uses gyroscopes to manouver. Their flywheels is spun up to high speeds and by turning the gimbals inertia makes the spacecraft move. All this is powered by electricity which the HST gets from its solar panels. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [August 17, 2007, 4:35pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/3 "2007-08-17T16:35:51Z")
[Hubble Site: Pointing](http://hubblesite.org/the_telescope/nuts_.and._bolts/spacecraft_systems/pointing/) > [@](#): > > Reaction wheels are Hubble’s “steering” system. The reaction wheels spin one way, and Hubble spins the other. Flight software commands the reaction wheels to spin, accelerating or decelerating as needed to rotate the telescope toward a new target. Hubble could be pointed at the moon. However, IIRC there’s an old thread on this, the resolution at that distance is about 100 yards per pixel. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [August 17, 2007, 4:52pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/4 "2007-08-17T16:52:38Z")
What about the _Harry S Truman?_ I suppose she just has a rudder. In port she would use tugs rather than bow-thrusters. ---
**Author:** ![Barrington](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Barrington](https://boards.straightdope.com/u/Barrington)\ **Post date:** [August 17, 2007, 5:00pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/5 "2007-08-17T17:00:54Z")
And I thought the OP was asking about the [High Speed Train](http://en.wikipedia.org/wiki/InterCity_125). That would have been an odd question. 🙂 ---
**Author:** ![MrFloppy](https://avatars.discourse-cdn.com/v4/letter/m/43a26b/32.png) [@MrFloppy](https://boards.straightdope.com/u/MrFloppy)\ **Post date:** [August 17, 2007, 5:08pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/6 "2007-08-17T17:08:22Z")
[QUOTE=Squink] [Hubble Site: Pointing](http://hubblesite.org/the_telescope/nuts_.and._bolts/spacecraft_systems/pointing/) Hubble could be pointed at the moon. However, IIRC there’s an old thread on this, the resolution at that distance is about 100 yards per pixel. [/QUOTE] Believe me, I understand resolution and Dawes Limits. And I thought HST was the accepted acronym. Thanks fellas. ---
**Author:** ![pravnik](https://avatars.discourse-cdn.com/v4/letter/p/8edcca/32.png) [@pravnik](https://boards.straightdope.com/u/pravnik)\ **Post date:** [August 17, 2007, 5:17pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/7 "2007-08-17T17:17:15Z")
Hunter S. Thompson? ---
**Author:** ![picker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/picker/32/13969_2.png) [@picker](https://boards.straightdope.com/u/picker)\ **Post date:** [August 17, 2007, 5:43pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/8 "2007-08-17T17:43:14Z")
[QUOTE=pravnik] Hunter S. Thompson? [/QUOTE] Hell, he could barely steer when he was alive! ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [August 17, 2007, 7:47pm UTC](https://boards.straightdope.com/t/how-does-the-hst-aim-or-steer/415954/9 "2007-08-17T19:47:26Z")
I thought to myself, “Hypersonic Transport? they _built_ one of those?”