IPB

Welcome Guest ( Log In | Register )

CEV Design Q&A
nprev
post Oct 6 2007, 02:45 AM
Post #1


Merciless Robot
****

Group: Admin
Posts: 8783
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Starting this thread in hopes that we'll all have some detailed insight into the next generation of MSF engineering.

Noble goal, eh? rolleyes.gif Truth of the matter is that I was just looking at one of the innumerable 'CEV enroute to the moon' artist conceptions, and I realized that the solar arrays as depicted meant that the vehicle almost certainly has to remain in a fixed attitude with respect to the Sun for them to operate at maximum efficiency. IIRC, the Apollos had to spin a bit in order to maintain thermal equilibrium & avoid localized heating and/or freezing.

Am I missing something here in terms of trade-offs? Seems unwieldy at best to have the arrays mounted to a sort of slip-ring assembly (with mast articulation) to maintain solar lock while the main body rotates. Likewise, seems as if an extensive--and in terms of power & volatile requirements/risk, expensive--ECS would be needed to avoid the temperature differential problem if the S/C is intended to maintain a continuous power-positive attitude during transit.

Sure that there's a simple answer I've missed; would very much like to hear it! smile.gif (Let me guess: LOTS of heat pipes?)


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
 
Start new topic
Replies
dvandorn
post Jan 19 2008, 06:27 PM
Post #2


Senior Member
****

Group: Members
Posts: 3419
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



Problem is, the CEV has been redesigned and made smaller once already, based on performance projections for the Stick. We're now at the raw edge of the Stick's current ability to orbit Orion as currently designed. Any reduction in performance will result in a further redesign that will severely limit the CEV's ability to perform its design mission.

I think we may be looking at the potential for changing over to an Atlas V or a Delta IV (in their Heavy configurations) as the first stage for Orion. Any such decision has to be made *very* soon, though.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post

Posts in this topic
- nprev   CEV Design Q&A   Oct 6 2007, 02:45 AM
- - ElkGroveDan   I have a CEV DVD that the PIO at Dryden gave me. ...   Oct 6 2007, 03:13 AM
|- - nprev   QUOTE (ElkGroveDan @ Oct 5 2007, 08:13 PM...   Oct 6 2007, 03:36 AM
- - dvandorn   Y'all have painted the Apollo thermal problem ...   Oct 6 2007, 07:58 AM
|- - Jim from NSF.com   I disagree. There wasn't a difference in the ...   Oct 6 2007, 03:08 PM
|- - dvandorn   QUOTE (Jim from NSF.com @ Oct 6 2007, 10...   Oct 7 2007, 03:16 PM
- - nprev   Aha! I was hoping that MSF sensei oDoug would ...   Oct 6 2007, 12:02 PM
- - ElkGroveDan   Here's a compressed version of the CEV demo vi...   Oct 6 2007, 06:31 PM
|- - ugordan   How old is that video? I might be out of loop, but...   Oct 6 2007, 06:43 PM
|- - ElkGroveDan   QUOTE (ugordan @ Oct 6 2007, 10:43 AM) Ho...   Oct 6 2007, 07:13 PM
|- - simonbp   QUOTE (ugordan @ Oct 6 2007, 12:43 PM) Ho...   Jan 2 2008, 10:10 PM
- - Jim from NSF.com   http://history.nasa.gov/SP-4011/ makes no mention...   Oct 8 2007, 12:26 AM
- - lyford   Nasa Constellation Program Draft Environmental Imp...   Dec 28 2007, 03:14 AM
- - PhilCo126   Check out this Orion 1/48 scale model: http://www....   Jan 15 2008, 10:18 AM
- - nprev   Apparently, a significant resonant vibration issue...   Jan 19 2008, 05:10 PM
|- - ugordan   From what I've read on nasaspaceflight.com thi...   Jan 19 2008, 05:34 PM
|- - nprev   QUOTE (ugordan @ Jan 19 2008, 09:34 AM) S...   Jan 19 2008, 06:04 PM
- - dvandorn   Problem is, the CEV has been redesigned and made s...   Jan 19 2008, 06:27 PM
|- - nprev   QUOTE (dvandorn @ Jan 19 2008, 10:27 AM) ...   Jan 19 2008, 06:42 PM
||- - Jim from NSF.com   QUOTE (nprev @ Jan 19 2008, 01:42 PM) esp...   Jan 20 2008, 02:00 PM
|- - ugordan   I don't think the problem can be adressed by c...   Jan 19 2008, 06:52 PM
|- - nprev   QUOTE (ugordan @ Jan 19 2008, 10:52 AM) I...   Jan 19 2008, 07:13 PM
- - Greg Hullender   Great opportunity for those SpaceX guys to get the...   Jan 20 2008, 04:50 PM


Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 28th March 2024 - 06:16 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 funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.