OSP requirements

Joann Evans wrote:
Dholmes wrote:

"Bob Martin" wrote in message
...

I'm interested in seeing what you guys would come up with if you were
writing the requirements for the OSP. Any takers?


I am kind of torn between large and small.

A simple capsule would require over a dozen launches a year giving some
needed volume.

A larger space plane would need only 3 or 4 launches a year but help to
develop heavy lift.

A capsule should be both cheap and quick to develop.

A large space plane while more expensive to develop has better follow on
when a reusable first stage is developed.



Most of those questions are the same ones we asked at the beginning
of shuttle development.

We ended up settling for a system that was (allegedly) cheaper to
develop, but more expensive to operate. Not that NASA didn't want the
TSTO all flyback stage designs that would have been the reverse, but it
soon became clear that Congress wouldn't pony up the higher up-front
costs, and there was much controversy over what the expected traffic
models were most realistic. The more traffic to orbit you expect, the
more a vehicle with lower operating costs (in spite of higher
development costs) make sense.


I will point out that it was necessarily Congress' fault. NASA
deliberately underestimated the costs and expected Congress to
pony up the funds later.

NASA had a number of projects they could have gone with. A much
smaller Shuttle, such as Faget's proposal, were fundable. And
a number of proposals for leveraging off the Saturn V line would
have been partially expendable, but would have kept the US Heavy
launch capability.


However, one of the opposing arguments was that a Mars mission would
be one of the projects for which this shuttle would be used for (NASA
would still be only user, after all), and this was a way of pulling the
rug from beneath the idea.

Similarly, you have to ask what an OSP will be used for. Mostly ISS
servicing? Do you dare suggest it might have the capacity of also
supporting another large manned project? (Moon/Mars/Near Earth Asteroid,
take your pick) Some people still don't want to hear that....

And are its payload capacity (volume and weight) and operating costs
such that there might be a commercial interest? NASA has long said it
wants a vehicle that is a convergence of the two. Others say (and I'm
strongly inclined to agree) that the needs are so different that such a
one-size-fits-all convergence may not be possible.

"Brian Thorn" wrote in message
...
On Fri, 29 Aug 2003 09:56:17 GMT, "Dholmes"
wrote:

Interestingly a 6 man OSP would weight about 20 tons and require a heavy
lift vehicle so it would really use three rockets.

I think you're over by a factor of two. the Apollo capsule (13,000
lbs) was rated for five crew (SkyLab rescue) six was easily possible,
and nine was an option if they really worked hard at reconfiguring the
cabin. A Service Module for ISS transport will weigh much less than
30,000 lbs. I don't see a capsule OSP variant for six crew being
anywhere near 20 tons.


The 13,000 lbs figure is for the reentry portion only.
You need maneuverability, power and other features in space and this
increases mass quite a bit.

If NASA goes for a big version they will IMO go for a plane.
I was actually basing my estimate on Orbitals proposal.
It weights 48,000 lbs and carries 5 up and 7 down plus some cargo.

You are correct that a capsule version would be lighter. Almost certainly
under 15 tons including extra safety features.

"Dholmes" wrote in message ...
"Mike Chan" wrote in message
om...


I am not sure about this, but it appears to me that Navstar IIF and
DMSP 5D could have used 7925 for launch. Instead, they are using
EELV's. An EELV program goal was to reduce launch cost to less than
50% of heritage LV's, so maybe they have reached that goal and a Delta
4M or Atlas V 401 is as cheap to buy as a 7925. That would allow
phasing out the Delta II 7900 LV's.

I am not sure but the IIR version needed the original 7295 and the IIF
according to most reports is 45% heavier and twice as wide. The new Delta 2
7925 heavy only lifts 15% more the original so I do not think it could
launch a IIF. It seems as if it was designed for the Delta 3. The Delta 4 is
probably a little over what is needed and will still be able to launch the
next version and probably with solids even the one after that.

I had thought Navstar IIF was only slightly heavier and larger than
the IIR. I did a google and found the numbers on

http://www.losangeles.af.mil/SMC/PA/.../gps/gpsfs.htm

So I was mistaken in thinking that a Delta IIH could launch a Navstar
IIF.

I'd better give Roman numeral designations a break for a while.

"Dholmes" wrote in message ...
"ed kyle" wrote in message
om...
OSP you add 10-25 launches a year.
15 rockets a year for each launcher would be a good jump start.

It would be, but I don't think we'll see it. Since 2000,
inclusive, the combined total of all Atlas, Delta, Titan, and
Shuttle launches have averaged 19.7 launches per year.

A lot will depend on what method is chosen for shuttle replacement. One for
one is not possible the shuttle carries seven people and 12.5 tons of cargo
to ISS and 25 tons to LEO.
The largest OSP I have seen is 5 people and less the 2 tons of cargo.
On the small size is 3 people and less then 1 ton of cargo.
You also need an ATV to send cargo, experiments and supplies.
In total for 4 shuttle flights, less then the average number you need
almost 6 of the large and 9+ of the small just for people.
....
In reality you are talking about just under 3 to as many as 7 flights to
replace a shuttle launch with 4 being the most likely.

There are also 10 medium to heavy American rockets planned over the next
year.

So you have a minimum of 21 launches and a max of 32 while still flying
one to two shuttle mission and absolutly no growth in the market. I could
see 40 by 2010-2020.

We need to adjust our thinking to the reality of our times -
an era for space that is more like the barren 1970s than the
interesting 1990s. ISS became irrelevant the instant that first
airliner attacked the North Trade Center tower. Now the priority
is finding the 10s of billions needed for the Southwest Asia/Middle
East Wars. Some of it will come out of NASA's hide, the way it
did during Vietnam when the Apollo program shrunk first to two
missions per year, and then *no* missions per year. Once a basic
ISS is assembled, NASA will simply not need to fly so many
missions - and Congress won't be able to provide funds for anything
beyond the basics. Russia supported Mir for years with only two
crewed flights and two to three Progress missions. Expect NASA to do
the same. Expect shuttle to be retired much earlier than currently
planned to save funds (it may have already flown its last flight).
Expect a modest CTV that flies 2-3 times per year, launched on
existing EELV rockets, Expect 2-3 cargo flights. Expect many
thousands fewer ground-support employees, and a smaller astronaut
corps. If things really go bad, expect *no* U.S. human space
flight program for awhile.

- Ed Kyle

Dholmes wrote:
"Brian Thorn" wrote:
"Dholmes" wrote:
Interestingly a 6 man OSP would weight about 20 tons and require a heavy
lift vehicle so it would really use three rockets.

I think you're over by a factor of two. the Apollo capsule (13,000
lbs) was rated for five crew (SkyLab rescue) six was easily possible,
and nine was an option if they really worked hard at reconfiguring the
cabin. A Service Module for ISS transport will weigh much less than
30,000 lbs. I don't see a capsule OSP variant for six crew being
anywhere near 20 tons.


The 13,000 lbs figure is for the reentry portion only.
You need maneuverability, power and other features in space and this
increases mass quite a bit.

If NASA goes for a big version they will IMO go for a plane.
I was actually basing my estimate on Orbitals proposal.
It weights 48,000 lbs and carries 5 up and 7 down plus some cargo.

You are correct that a capsule version would be lighter. Almost certainly
under 15 tons including extra safety features.

Please explain why you need twice the mass of the British Aerospace
Multi Role Capsule design, for the same mission?


-george william herbert

"George William Herbert" wrote in message
...
Dholmes wrote:
"Brian Thorn" wrote:
"Dholmes" wrote:
Interestingly a 6 man OSP would weight about 20 tons and require a
heavy
lift vehicle so it would really use three rockets.

I think you're over by a factor of two. the Apollo capsule (13,000
lbs) was rated for five crew (SkyLab rescue) six was easily possible,
and nine was an option if they really worked hard at reconfiguring the
cabin. A Service Module for ISS transport will weigh much less than
30,000 lbs. I don't see a capsule OSP variant for six crew being
anywhere near 20 tons.


The 13,000 lbs figure is for the reentry portion only.
You need maneuverability, power and other features in space and this
increases mass quite a bit.

If NASA goes for a big version they will IMO go for a plane.
I was actually basing my estimate on Orbitals proposal.
It weights 48,000 lbs and carries 5 up and 7 down plus some cargo.

You are correct that a capsule version would be lighter. Almost certainly
under 15 tons including extra safety features.

Please explain why you need twice the mass of the British Aerospace
Multi Role Capsule design, for the same mission?

For several reasons.

First I am trying to be conservative because IMO NASA will be.
Second I am comparing the capsule to existing and proposed capsules. Suyoz,
Apollo, Gemini and Big Gemini among others.
Third I am trying to meet what NASA has said they wish to accomplish which
includes some maneuverability.
Fourth I was giving a max figure not a lower end.
Fifth the capsule you refer to is more of a lifeboat then something that
NASA would call a space plane.
The Multi Role is very light with low maneuverability, low cargo capacity
seats 4 comfortably and is designed with no additional safety features.
NASA has said at least 4, moderate to high manuvarabity, some cargo
capability and extra saftey features.