OSP requirements

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

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"Flying, like the sea, is not inherently dangerous... just extremely
unforgiving"

"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.

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

I would not work it as a contract but as a prize / purchase.
Set a date along with performance and cost requirments and
announce that NASA will most definitely buy a certain
quantity of services or vehicles that meet the requirments
on that date from whichever company (or whichever two
companies perhaps) provides the cheapest and best.

Though it might be easier and better to work it as a prize.

On Wed, 27 Aug 2003 22:00:23 GMT, "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.



Which launch facilities will an OSP use? Is NASA going to use Pads 37
& 40 for an OSP, or will it be assembled in the VAB and ride the
crawler to Pads 39A & B? It's kind of the same dilemma that NASA faced
with the Saturn IB for the Skylab project.

Now where did that Milk Stool go? ;-)

I favor a capsule system. But I don't think any one vehicle type is
the complete solution to orbital access. There is a place for both
planes and capsules. Now if we only had the money for both.

With a capsule system you can start out simple and add complexity as
needed. A capsule is a basic Crew Return Vehicle. Add a Service Module
and you have a Crew Transfer Vehicle. Add an Orbital, Cargo or Boost
Module and you have a Space Station supply and reboost vehicle.

Start out with a parachute or parasail landing system. Later, add a
rotor or roton type landing system if possible or practical. Or as
Henry mentioned a hot air balloon!

A capsule launch escape system has already been designed, tested, used
and proven to work.

You just can't land on a runway or return large objects from orbit
with a capsule.

But, wings are not much use on the way to the moon or Mars. ;-)

"Rusty Barton" wrote in message
...
Which launch facilities will an OSP use? Is NASA going to use Pads 37
& 40 for an OSP, or will it be assembled in the VAB and ride the
crawler to Pads 39A & B? It's kind of the same dilemma that NASA faced
with the Saturn IB for the Skylab project.

That's the subject of several trade studies going on right now (and which
I'm lucky enough to participate in - seems that USA pad rat experience was
good for something, after all). A number of interesting options are in play,
involving SLC 37A & B, 39, 40, and 41. Imagine being asked to design a pad
that can handle two different launch vehicles - that's the challenge of the
Cx 39 study. Add to that the confusion of being given three generic shapes
for OSP and having to accomodate them in the design. Not knowing where the
crew hatch is going to be adds more uncertainty These are just studies,
providing ROM numbers and lots of ideas, but I don't know how the decision
process will flow after the studies are done.

But, wings are not much use on the way to the moon or Mars. ;-)

Chesley Bonestell thought they were!

-Kim-

I would not work it as a contract but as a prize / purchase.
Set a date along with performance and cost requirments and
announce that NASA will most definitely buy a certain
quantity of services or vehicles that meet the requirments
on that date from whichever company (or whichever two
companies perhaps) provides the cheapest and best.

Though it might be easier and better to work it as a prize.

I meant something kind of like this (just an example and I'm pulling numbers
out of my ass for this):

Carry 4 people plus 2000lb of supplies

Cross-range of 400mi

Launch escape for full flight profile, including standing on pad

Launchable on either EELV (not having to use heavy version a plus)

Vehicle-specific LV allowed

Capable of independent operation (like hubble repair) with reduced crew

600 ft/s delta-v

Most important:

No more than 4 years from issue of requirements to first orbital flight
(need not be manned for this)

Demonstrated flight rate of 2/month

Cheap

"Kim Keller" wrote in message m...
"Rusty Barton" wrote in message
...
Which launch facilities will an OSP use?

That's the subject of several trade studies going on right now (and which
I'm lucky enough to participate in - seems that USA pad rat experience was
good for something, after all). A number of interesting options are in play,
involving SLC 37A & B, 39, 40, and 41. Imagine being asked to design a pad
that can handle two different launch vehicles - that's the challenge of the
Cx 39 study. ...

With currently planned EELV launch rates averaging only 2
per year per vehicle and with neither EELV agressively
competing for commercial launches, an all-new launch pad
is the last thing NASA needs to pour money into, IMO.
When Shuttle is retired, NASA should scrap LC 39 to save
money.

- Ed Kyle

"Ian Woollard" wrote in message
...
Bob Martin wrote:

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

The only requirement that I see that is necessary is that the launched
payload be one person. Not two people, not atleast one person, not three
people. Exactly one person.

This has got to be one of the most radical and creative ideas I have seen in
a long time.


The reason that it should be one person is that that forces the launch
rate up by a factor of 7 or more.

Volume probably in terms of cost the biggest flaw of the shuttle.


Now, the cost of launch per person is very roughly independent of
vehicle size if the launch rate is the same (not quite, but near
enough,) but economies of scale mean that the cost per launch goes down
with launch rate. (Roughly 15% cheaper for each doubling). So launching
4x instead of 1 vehicle with 4 people in is only half the cost.


Not exactly.
First smaller vehicles do usually cost much more per pound then larger
vehicles.
Second the vehicles mass per person increases when you scale it down.
Third even if your 15% figure is correct that is closer to 3/4 not 1/2.


So, forcing the payload size down, forces the launch rate up by a the
same factor, which means that they have to put in facilities for
launching more quickly, production lines for handling it, and quality
control becomes much better because you get immediate feedback.

All true.

Now, there will be a lot of whining. "The space shuttle was better
because it could launch 7!". True, but the space shuttle is less
advanced because it could only launch once per month, whereas this
system will *have* to launch once a week or more.

Actually since you need cargo as well the number could be even a little
higher. 28 passenger flights, 20+ returnable experiment flights and 20-40
cargo flights totaling probably betterthen 70 flights

"We should use SSTO, TSTO, Orion and/or fully reusable" I don't care
what you use, as long as it works and is reasonably safe. With a payload
of one, you launch more, so whatever you use works out much cheaper.
Arguably fully reusable is not as appropriate at the launch rate we see
today; but if you launch more often then it will start to be more
appropriate.

True reusable only makes sense with high volume. With low numbers it is more
of a hindrance since each part becomes more or less unique without the
benefit of mass production.

"That will disrupt the operations at the ISS too much." True, it will be
more disruptive, but accepting more frequent visits also means that you
can send more people up there and more resources, since it is cheaper to
do so. So you get more resource on orbit to do stuff.

Where exactly do you plan on putting 7-10 capsules at any one time?



Overall, the ONLY sensible number of people to launch is One.

Summary:

- one is the only way to go
- it's not dumb pride it's dumb economics
- it cuts the cost by a factor of 2 or more
- it's safer
- staffing doesn't go down


A few points you missed.
1) This means everyone has to be a pilot.
2) What about emergencies? If each person has to pilot themselves a sick
person is in trouble.
3) We have no rocket that small. Even the base Delta II would be too large
4) The largest part of the savings is in the first few multiples.1-1,
2-0.85, 4-0.72, 8-0.61, 16-0.52, 32-0.44, 64-0.38...1024-.23. Once you get
over 32 the saving per launch is minor.

Three man capsules would give you almost the same savings with over 20
flights total but using a cheaper per pound rocket and a slight lighter per
person capsule.

Where this idea truly shines is cargo a weekly or bi weekly cargo launch
would create 26-52 launches a year more then enough for significant savings
to occur. While the rocket would only have to be attached to the station for
a short time.

Dholmes wrote:
"Ian Woollard" wrote in message
...
The only requirement that I see that is necessary is that the launched
payload be one person. Not two people, not atleast one person, not three
people. Exactly one person.

This has got to be one of the most radical and creative ideas I have seen in
a long time.

Thanks.

The reason that it should be one person is that that forces the launch
rate up by a factor of 7 or more.

Volume probably in terms of cost the biggest flaw of the shuttle.

I would say so.

Now, the cost of launch per person is very roughly independent of
vehicle size if the launch rate is the same (not quite, but near
enough,) but economies of scale mean that the cost per launch goes down
with launch rate. (Roughly 15% cheaper for each doubling). So launching
4x instead of 1 vehicle with 4 people in is only half the cost.


Not exactly.
First smaller vehicles do usually cost much more per pound then larger
vehicles.

True, but that's mainly for really small vehicles, and a lot of those
have low launch rates, and often use solid rockets and extra stages and
other problems.

Second the vehicles mass per person increases when you scale it down.

Not significantly at the ~250kg scale that is a person in a spacesuit,
and by the time you add on reentry mass it's not significant. It gets
pretty bad at 50-100kg. Besides, mass isn't the question, it's cost.

Third even if your 15% figure is correct that is closer to 3/4 not 1/2.

Yes, you're right, it's 70% or so. To launch 7-8 people is about half
the cost per person.

Now, there will be a lot of whining. "The space shuttle was better
because it could launch 7!". True, but the space shuttle is less
advanced because it could only launch once per month, whereas this
system will *have* to launch once a week or more.

Actually since you need cargo as well the number could be even a little
higher. 28 passenger flights, 20+ returnable experiment flights and 20-40
cargo flights totaling probably betterthen 70 flights

Yes. Although the cargo might be better off on different transport or a
different version of the same transport- cargo doesn't necessarily need
reentry equipment.

True reusable only makes sense with high volume. With low numbers it is more
of a hindrance since each part becomes more or less unique without the
benefit of mass production.

"That will disrupt the operations at the ISS too much." True, it will be
more disruptive, but accepting more frequent visits also means that you
can send more people up there and more resources, since it is cheaper to
do so. So you get more resource on orbit to do stuff.

Where exactly do you plan on putting 7-10 capsules at any one time?

It may be possible to scale the vehicle so that it launches with one
person, but can return with 2 people. That way you would only need to
keep half the number of capsules on orbit. The rest can reenter with
waste, or tethered nearby as backup.

A few points you missed.
1) This means everyone has to be a pilot.

Perhaps. However automatic control can be performed in an emergency.

2) What about emergencies? If each person has to pilot themselves a sick
person is in trouble.

That's never happened yet, and automatic control would very probably
work- the Shuttle mostly deorbits automatically anyway. Having two
return seats would solve the problem and add only a little mass.

3) We have no rocket that small. Even the base Delta II would be too large

Delta-II is not manrated however, so it's not totally clear that we have
that either.

4) The largest part of the savings is in the first few multiples.1-1,
2-0.85, 4-0.72, 8-0.61, 16-0.52, 32-0.44, 64-0.38...1024-.23. Once you get
over 32 the saving per launch is minor.

At some point, space tourism probably starts to take off... You may very
well get a few thousand people wanting to go to space at a million bucks
a trip. Even if not, the early reductions in launch price are worth having.

Three man capsules would give you almost the same savings with over 20
flights total but using a cheaper per pound rocket and a slight lighter per
person capsule.

It's still more expensive; the difference in mass is largely irrelevant.
There's also subtle advantages in that it's more flexible to launch
people one at a time.

Where this idea truly shines is cargo a weekly or bi weekly cargo launch
would create 26-52 launches a year more then enough for significant savings
to occur. While the rocket would only have to be attached to the station for
a short time.

That too.

Jim Davis wrote:
Are you comfortable with the notion of requiring all astronauts to be pilots
or do you intend to embrace remote or automatic piloting?

I don't see this as either/or.

I don't see that remote piloting is advisable, communication drop-outs
are not rare. But automatic piloting is more or less inevitable-
essentially all current space vehicles are fly-by-wire and capable of
landing autonomously.

Which is not to say that pilots are not needed, particularly test pilots.

Jim Davis