SMART-1 impact, September 2006 |
SMART-1 impact, September 2006 |
Mar 16 2006, 05:26 PM
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Solar System Cartographer Group: Members Posts: 10226 Joined: 5-April 05 From: Canada Member No.: 227 |
Emily posted a very nice article in her blog on the SMART-1 lunar impact in September this year. Here's a map of the targeted point:
But as Emily explained, the actual point may be off because of uncertainties about topography. I'm starting this thread to have a place for news and opinions on it, and - I really hope - maybe some observations at the time from any amateur astronomers out there. This event will be the last event to make it into my atlas. I've left a space for it, and I will make the final maps and fit them in, and then send the stuff off to the publisher. Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PDF: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jun 29 2006, 02:29 AM
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Senior Member Group: Members Posts: 1870 Joined: 20-February 05 Member No.: 174 |
It's "nice" but not always "necessary" to have balanced attitude control jets, with two jets on opposite sides of a spacecraft's center-of-gravity firing in perfect opposition to rotate the spacecraft without any change in velocity. For a spacecraft doing fine attitude and translational maneuvers in close proximity to another spacecraft, like an Apollo rendezvouis and docking, yes, it's necessary, but often, it's not.
That, of course, is what killed Mars Climate Orbiter. The spacecraft was assymetrical, with one solar panel, and offloaded solar light pressure which slowly spun up the momentum wheels with weekly attitude thruster firings. The firings also imparted a small velocity change on the spacecraft that needed to be included in trajectory calculations. It was.. in the wrong units (english vs metric) throwing off the trajectory models in a particularly insidious way. |
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Lo-Fi Version | Time is now: 22nd September 2024 - 10:53 PM |
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