A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Policy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

HST repair delayed; Ares 1-X launch slips



 
 
Thread Tools Display Modes
  #11  
Old November 1st 08, 12:37 AM posted to sci.space.policy,sci.space.history
Pat Flannery
external usenet poster
 
Posts: 18,465
Default HST repair delayed; Ares 1-X launch slips



Rick Jones wrote:
Wish I fully understood it I wonder what is done in
Merlin-1C/Falcon[19] wrt the issue?


It will make your scrotum vibrate painfully; that's all I had to
understand to rule out any flights on a large rocket for me. :-D
Seriously, it generally occurs with larger engines or clusters of
engines; so Falcon 9 would probably be more prone to it than Falcon 1,
as all nine engines firing at once could generate interesting harmonic
effects among them.
Saturn I apparently didn't have many pogo problems though, and that's
probably about the closest analogy to Falcon 9 in design, at least as
far as clustered engines go.

Pat
  #12  
Old November 1st 08, 07:03 AM posted to sci.space.policy,sci.space.history
Jorge R. Frank
external usenet poster
 
Posts: 2,089
Default HST repair delayed; Ares 1-X launch slips

Fred J. McCall wrote:
Ian Parker wrote:
:
:I have just read an article in the Times which says that Apollo/saturn
:veterans are being drafted in to sort out the Ares problems.
:

Which "Times" and could we have a real cite to that?


Regardless of which Times, it's partially true.

Apollo/Saturn veterans are involved in Constellation, but they've been
involved since the beginning, not just "to sort out the Ares problems."

You do realize that "Apollo/Saturn veterans" would be in their 80's or
older by now, right?


Not all of them. Some are in their late 60s and early 70s. Some never
even retired. Al Pennington (Apollo INCO and shuttle flight director) is
working Constellation, for example. So are John Young and T. K. Mattingly.
  #13  
Old November 2nd 08, 02:15 AM posted to sci.space.policy,sci.space.history
Brian Thorn[_2_]
external usenet poster
 
Posts: 2,266
Default HST repair delayed; Ares 1-X launch slips

On Fri, 31 Oct 2008 17:37:37 -0600, Pat Flannery
wrote:

Saturn I apparently didn't have many pogo problems though, and that's
probably about the closest analogy to Falcon 9 in design, at least as
far as clustered engines


I wonder if that had something to do with all the different prop tanks
in Stage 1.

Brian
  #14  
Old November 2nd 08, 03:57 AM posted to sci.space.policy,sci.space.history
Pat Flannery
external usenet poster
 
Posts: 18,465
Default HST repair delayed; Ares 1-X launch slips



Brian Thorn wrote:
I wonder if that had something to do with all the different prop tanks
in Stage 1.


The odd design of the Saturn I first stage was due to the fact that they
wanted it to be built as quickly as possible and at low cost.
They already had the tooling to make Redstone and Jupiter missile
tankage, so the first stage consisted of a stretched Jupiter tank
surrounded by eight stretched Redstone tanks. The Jupiter tank and four
alternating Redstone tanks held LOX; the other four held kerosene.
Although clunky from a weight versus propellant capacity way of doing
things, it really sped up the development time of the booster and cut
R&D costs a lot.
The initial versions of Saturn I were ready to go in such a hurry that
NASA didn't have any payloads designed to put on them at first.

Pat
  #15  
Old November 3rd 08, 12:51 AM posted to sci.space.policy,sci.space.history
Brian Thorn[_2_]
external usenet poster
 
Posts: 2,266
Default HST repair delayed; Ares 1-X launch slips

On Sun, 02 Nov 2008 09:56:23 -0600, OM
wrote:


I wonder if that had something to do with all the different prop tanks
in Stage 1.


The odd design of the Saturn I first stage was due to the fact that they
wanted it to be built as quickly as possible and at low cost.


...Actually, what I think Brian was referring to was the lack of
severe pogo, which IIRC was worked out to have been due to all that
tankage acting as dampeners for the harmonics that otherwise would
have had more free range had the Saturn I first stage been, say, two
big wide tanks instead of nine smaller, thin ones.


Yes, that's what I was after. But I don't know if that is actually
true.

Brian
  #16  
Old November 3rd 08, 01:15 AM posted to sci.space.policy,sci.space.history
Pat Flannery
external usenet poster
 
Posts: 18,465
Default HST repair delayed; Ares 1-X launch slips



Brian Thorn wrote:
Yes, that's what I was after. But I don't know if that is actually
true.


I don't know if multiple propellant tanks would help or not, it would
certainly cut down propellant sloshing a great deal, but that problem
was already addressed many years ago around the time that the Jupiters
started going out of control as their propellants started shifting
during launch.
From the article on pogo, it seems to imply that the root problem is
pressure spikes in the turbopump plumbing.
Here's a image of the pogo suppressor on the SSME:
http://www.engineeringatboeing.com/a...ges/pogo5.jpeg
(That's from here, BTW:
http://www.engineeringatboeing.com/articles/pogo.htm )
I've been looking at photos and drawings of the Merlin engine showing a
similar structure, but haven't spotted one yet.

Pat
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Ares-1 delayed 1 year? Pat Flannery History 30 January 23rd 08 01:42 PM
Ares-1 delayed 1 year? Rand Simberg[_1_] Policy 25 January 22nd 08 10:05 PM
Ares I already delayed? apozo Policy 3 October 11th 06 04:34 AM


All times are GMT +1. The time now is 12:05 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.