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LADEE
Paolo
post Jun 28 2012, 03:25 PM
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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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Paolo
post Jul 21 2012, 03:47 PM
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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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Phil Stooke
post Jul 21 2012, 04:25 PM
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I thought Chang'E 3 was scheduled for October.

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Paolo
post Jul 21 2012, 05:11 PM
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I only saw it mentioned as "second half" of 2013
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Paolo
post Jan 4 2013, 06:19 AM
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now with solar panels attached http://www.nasa.gov/mission_pages/LADEE/ne...-03_update.html
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Explorer1
post Aug 22 2013, 06:52 PM
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LADEE briefing in a few minutes:
http://www.nasa.gov/multimedia/nasatv

EDIT: Grunsfeld's tie!
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belleraphon1
post Aug 23 2013, 11:50 AM
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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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John D. Pritchar...
post Sep 3 2013, 09:58 PM
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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
  • 10 -11:30 a.m. – NASA Social for LADEE Mission Live from the Wallops Flight Facility – HQ/WFF (Education Channel)

  • 3 p.m. – LADEE Prelaunch Mission Briefing – HQ/WFF (All Channels)
  • 4 p.m. – LADEE Mission Science and Technology Demonstration Briefing – HQ/WFF (All Channels)

September 6, Friday
  • 6-10 a.m. –Live Interviews on the LADEE Mission – HQ/WFF (All Channels)
  • 4-6 p.m. – Live Interviews on LADEE Mission – HQ/WFF (All Channels)
  • 9:30 p.m. – Live Launch Coverage and Commentary on LADEE Mission – HQ/GSFC/WFF (Public and Media Channels)
  • 9:30 p.m. – Simulcast of NASA EDGE Live Webcast of LADEE Mission and Launch – LARC/HQ/WFF (Education Channel)

September 7, Saturday
  • 2 a.m. – LADEE Post Launch News Conference –HQ/WFF (All Channels)
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Explorer1
post Sep 4 2013, 02:28 AM
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Welcome, John, and thanks for the comprehensive list!
All times are in Eastern, by the way.
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John D. Pritchar...
post Sep 4 2013, 03:21 AM
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QUOTE (Explorer1 @ Sep 3 2013, 09:28 PM) *
Welcome, John, and thanks for the comprehensive list!

Thanks for the welcome

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CryptoEngineer
post Sep 6 2013, 09:37 PM
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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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djellison
post Sep 6 2013, 11:01 PM
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QUOTE (CryptoEngineer @ Sep 6 2013, 02:37 PM) *
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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mcaplinger
post Sep 6 2013, 11:11 PM
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QUOTE (djellison @ Sep 6 2013, 04:01 PM) *
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


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Disclaimer: This post is based on public information only. Any opinions are my own.
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ChrisC
post Sep 7 2013, 02:50 AM
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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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Explorer1
post Sep 7 2013, 03:15 AM
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T-11 minutes...

EDIT: Liftoff! It shot up so fast!
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