IPB

Welcome Guest ( Log In | Register )

3 Pages V   1 2 3 >  
Reply to this topicStart new topic
LADEE
Paolo
post Jun 28 2012, 03:25 PM
Post #1


Senior Member
****

Group: Members
Posts: 1581
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
Go to the top of the page
 
+Quote Post
Paolo
post Jul 21 2012, 03:47 PM
Post #2


Senior Member
****

Group: Members
Posts: 1581
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?
Go to the top of the page
 
+Quote Post
Phil Stooke
post Jul 21 2012, 04:25 PM
Post #3


Martian Cartographer
****

Group: Members
Posts: 7087
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.
Go to the top of the page
 
+Quote Post
Paolo
post Jul 21 2012, 05:11 PM
Post #4


Senior Member
****

Group: Members
Posts: 1581
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
Go to the top of the page
 
+Quote Post
Paolo
post Jan 4 2013, 06:19 AM
Post #5


Senior Member
****

Group: Members
Posts: 1581
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
Go to the top of the page
 
+Quote Post
Explorer1
post Aug 22 2013, 06:52 PM
Post #6


Senior Member
****

Group: Members
Posts: 1394
Joined: 13-February 10
From: British Columbia
Member No.: 5221



LADEE briefing in a few minutes:
http://www.nasa.gov/multimedia/nasatv

EDIT: Grunsfeld's tie!
Go to the top of the page
 
+Quote Post
belleraphon1
post Aug 23 2013, 11:50 AM
Post #7


Member
***

Group: Members
Posts: 809
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


Go to the top of the page
 
+Quote Post
John D. Pritchar...
post Sep 3 2013, 09:58 PM
Post #8


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
  • 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)
Go to the top of the page
 
+Quote Post
Explorer1
post Sep 4 2013, 02:28 AM
Post #9


Senior Member
****

Group: Members
Posts: 1394
Joined: 13-February 10
From: British Columbia
Member No.: 5221



Welcome, John, and thanks for the comprehensive list!
All times are in Eastern, by the way.
Go to the top of the page
 
+Quote Post
John D. Pritchar...
post Sep 4 2013, 03:21 AM
Post #10


Newbie
*

Group: Members
Posts: 2
Joined: 3-September 13
From: Leonardo, NJ, US
Member No.: 6999



QUOTE (Explorer1 @ Sep 3 2013, 09:28 PM) *
Welcome, John, and thanks for the comprehensive list!

Thanks for the welcome

Go to the top of the page
 
+Quote Post
CryptoEngineer
post Sep 6 2013, 09:37 PM
Post #11


Junior Member
**

Group: Members
Posts: 34
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
Go to the top of the page
 
+Quote Post
djellison
post Sep 6 2013, 11:01 PM
Post #12


Administrator
****

Group: Chairman
Posts: 13987
Joined: 8-February 04
Member No.: 1



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
Go to the top of the page
 
+Quote Post
mcaplinger
post Sep 6 2013, 11:11 PM
Post #13


Senior Member
****

Group: Members
Posts: 1560
Joined: 13-September 05
Member No.: 497



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


--------------------
Disclaimer: This post is based on public information only. Any opinions are my own.
Go to the top of the page
 
+Quote Post
ChrisC
post Sep 7 2013, 02:50 AM
Post #14


Junior Member
**

Group: Members
Posts: 41
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
Go to the top of the page
 
+Quote Post
Explorer1
post Sep 7 2013, 03:15 AM
Post #15


Senior Member
****

Group: Members
Posts: 1394
Joined: 13-February 10
From: British Columbia
Member No.: 5221



T-11 minutes...

EDIT: Liftoff! It shot up so fast!
Go to the top of the page
 
+Quote Post

3 Pages V   1 2 3 >
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 26th April 2017 - 12:07 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.