LADEE |
LADEE |
Jun 28 2012, 03:25 PM
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#1
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
I thought it was time to start a new topic on NASA's next Moon mission
incidentally, there is a new mission update out today |
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Jul 21 2012, 03:47 PM
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#2
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
LADEE launch is now expected in August 2013 http://msdb.gsfc.nasa.gov/change_log.php
so who will launch first? LADEE or Chang'e 3? |
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Jul 21 2012, 04:25 PM
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#3
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Solar System Cartographer Group: Members Posts: 10151 Joined: 5-April 05 From: Canada Member No.: 227 |
I thought Chang'E 3 was scheduled for October.
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 PD: 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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Jul 21 2012, 05:11 PM
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#4
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
I only saw it mentioned as "second half" of 2013
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Jan 4 2013, 06:19 AM
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#5
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
now with solar panels attached http://www.nasa.gov/mission_pages/LADEE/ne...-03_update.html
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Aug 22 2013, 06:52 PM
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#6
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Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
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Aug 23 2013, 11:50 AM
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#7
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
LADEE briefing from 08/22/2013 on Youtube in case folks missed it.
LADEE briefing 08/22/2013 http://www.youtube.com/watch?v=hTzo0Lq1-T4 Craig |
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Sep 3 2013, 09:58 PM
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#8
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Newbie Group: Members Posts: 2 Joined: 3-September 13 From: Leonardo, NJ, US Member No.: 6999 |
LADEE launch window 6 SEP 2013 23:27 EDT for 4 minutes
Launch windows analysis results (pdf) Citizen Science http://www.nasa.gov/mission_pages/LADEE/ma...ml#.UiYoMd-m0ak Looking for telescopic lunar impact flashes and Earth meteor counts for LADEE mission duration. Twitter coverage NASA TV coverage September 5, Thursday
September 6, Friday
September 7, Saturday
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Sep 4 2013, 02:28 AM
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#9
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Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
Welcome, John, and thanks for the comprehensive list!
All times are in Eastern, by the way. |
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Sep 4 2013, 03:21 AM
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#10
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Newbie Group: Members Posts: 2 Joined: 3-September 13 From: Leonardo, NJ, US Member No.: 6999 |
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Sep 6 2013, 09:37 PM
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#11
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Junior Member Group: Members Posts: 39 Joined: 5-June 06 Member No.: 803 |
I look forward to LADEE's launch tonight.
One of the more intriguing bits of new kit is the LLCD - a laser based communication system. It has a number of advantages over radio; smaller size & power, greatly improved data rates, and it doesn't require exclusive use of a chunk of radio spectrum. But there are still things I wonder about. 1. How do the two ends find each other? At lunar distance the 'spot' illuminated by the laser is only a few miles across. 2. There are three ground sites - one in California, one in New Mexico, and one in Tenerife; how does it know where to look? 3. The laser operates in the near infra-red. To what extent can it deal with cloud? I presume there's some beacon mechanism to indicate 'look more closely here', but its not described. To what extent can it deal with slew? Would this mechanism be useful for Earth-orbit-to-ground communications? CE |
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Sep 6 2013, 11:01 PM
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#12
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Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
1. How do the two ends find each other? No different to radio - you need to know where you are, and where the station is. MRO has to know where the Earth is. Goldstone has to know where MRO is, for example. QUOTE 2. There are three ground sites - one in California, one in New Mexico, and one in Tenerife; how does it know where to look? Same as radio - by programming in the appropriate information. It's a simple geometry problem. QUOTE 3. The laser operates in the near infra-red. To what extent can it deal with cloud? I don't believe it can. Higher freq radio struggles with rain. The increase in bandwidth more than makes up for the times when you can't communicate (i.e. 10x faster, but maybe you drop 1 day in 10 is still a 9 fold increase) QUOTE To what extent can it deal with slew? Would this mechanism be useful for Earth-orbit-to-ground communications? No different, again, to radio - you just need slightly tighter pointing control. Spacecraft-to-Spacecraft laser has already been tested, as has orbiter to ground with Alphasat and ESA intends to use it in their version of TDRS. LRO has received data via laser into LOLA. Doug |
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Sep 6 2013, 11:11 PM
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#13
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Senior Member Group: Members Posts: 2511 Joined: 13-September 05 Member No.: 497 |
No different to radio... Actually, I think the spot size is small enough that a separate wider-field (or scanned, maybe, not clear) acquisition beam has to be sent by the ground station so that the flight system can adjust its pointing dynamically -- see http://dspace.mit.edu/openaccess-dissemina....1/61673 -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Sep 7 2013, 02:50 AM
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#14
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Junior Member Group: Members Posts: 59 Joined: 4-July 08 Member No.: 4251 |
Oh, it's definitely different from radio alright. About 4-5 orders of magnitude different. The far higher frequencies of light mean a far smaller beamwidth than a typical radio link, so they have to use spatial searching algorithms. See this video (cued up to the right moment) for a very brief discussion of this. https://www.youtube.com/watch?v=03BN7_4N0yQ&t=38s
More info here: http://www.nasa.gov/sites/default/files/ll...final_.web_.pdf |
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Sep 7 2013, 03:15 AM
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#15
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Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
T-11 minutes...
EDIT: Liftoff! It shot up so fast! |
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