From: jamesoberg@aol.com (JamesOberg)
Newsgroups: sci.space.shuttle
Subject: STS Performance Penalty of Russian Partnership
Date: 8 Feb 1999 00:20:17 GMT

Just to revisit this topic, since a friend asked me to summarize and I figured
I'd share the answer with everybody...

1. STS performance to SS Freedom at 28 degrees, standard altitude, was
baselined at 36,000 lbs.

2. Switching to 51 degrees reduced payload about 8,000 lbs, to 28,000 lbs.

3. Performance enhancements (super lightweight tank, others) boosted
performance to 51 degrees back to 36,000 lbs, the same as Freedom had at 28
degrees.

NASA story stops here. "NO IMPACT of plane change".

True story has more lines.

4. Applying the same performance enhancements to a theoretical space station
launch to 28 degrees gives about 48,000 lbs, still within the envelope of abort
landing safety.

5. One caveat is that often a payload becomes volume or CG limited before it
becomes weight limited. It will hit such a limit sooner at 28 than at 51
because the weight limit ceiling is higher. Moving the station back to 28
degrees would not result in every flight being able to carry 10-12,000 lbs
more.

But most would.

The ratio I talk about in public is for every three flights to carry
station-bound cargo to 28 degrees, going to 51 degrees requires THOSE three
PLUS a fourth flight to carry the cargo bumped off the first three by the lower
max weight ceiling.

A station assembly and exploitation manifest involving, say, 60 shuttle flights
to 28 degrees over the lifetime of the program would require about 20 MORE
flights to 51 degrees. At a half billion per flight, that dominates any 'cost
savings' of having the Russians aboard.

No wonder NASA scrupulously does not tally launch costs as part of total
program costs!

Last October when I raised this very issue at my congressional testimony,
Goldin -- sitting two places to my right at the witness table -- launched into
a diatribe about how I was personally insulting him and every employee of NASA
by accusing NASA of covering up the extra costs associated with the Russian
partnership. I figured that was an implicit endorsement of the validity of my
computations.

These ratios are not nearly as vicious for expendable vehicles -- there's maybe
a 2% performance penalty going from 28 to 51 degrees, so for Skylab and even
ASTP it really was only a minor factor. But that 2% or so applies to EVERYTHING
inserted into orbit, and for the shuttle, that includes the humongous orbiter
(and ET) -- so the payload is the only really 'negotiable' item, once you've
shaved the SWL tank to a minimum.

Newsgroups: sci.space.shuttle
From: henry@spsystems.net (Henry Spencer)
Subject: Re: STS Performance Penalty of Russian Partnership
Date: Mon, 8 Feb 1999 01:56:22 GMT

In article <hDqv2.20940$b8.9542956@hme2.newscontent-01.sprint.ca>,
Ali Hammoud <ali@NOhammoud.net> wrote:
>As I understand it, the ISS will overfly a much bigger area than a 28
>degrees Freedom Space station.  Has anyone tried to compute the
>benefits for Earth Sciences?  Or is the observation of the earth not
>one of the main science objectives?

I believe it's basically a secondary objective.  The higher inclination
permits more of it, which is nice, but by itself, that wasn't enough to
justify the change of inclination.  And reasonably so, too -- the station
has only modest advantages over unmanned camera platforms for this
purpose, and most of those could be eliminated by design revisions to the
unmanned platforms if people cared enough.  Snapping pictures is one thing
we know how to do perfectly satisfactorily by remote control.
--
The good old days                   |  Henry Spencer   henry@spsystems.net
weren't.                            |      (aka henry@zoo.toronto.edu)

From: jamesoberg@aol.com (JamesOberg)
Newsgroups: sci.space.shuttle
Subject: Re: STS Performance Penalty of Russian Partnership
Date: 8 Feb 1999 03:21:53 GMT

<<As I understand it, the ISS will overfly a much bigger area than a 28
degrees Freedom Space station.  Has anyone tried to compute the
benefits for Earth Sciences?  Or is the observation of the earth not
one of the main science objectives?>>

There never were any, until we were forced into the orbital inclination. And
NASA does brag about the possibilities but doesn't fund any instruments.
Surprised?