cheap access to space - majority opinion

"Andrew Nowicki" wrote in message
...

{general discussion snipped}
________________________________________________

MY CONCLUSION

Space tethers and guns... {snip}

When the rocket reaches 6 km/s, it deposits its
cargo at the end of orbital sling (Robert Forward
called it bolo.)... {snip}

The sling has a built-in aluminum wire which
is used as an electrodynamic tether... {snip}

The system of Earth-to-orbit transportation
I have just described is not made of unobtanium.
All its technologies have been tested; they are
cheap and reliable...

Tested? Cheap?? Reliable?!?

Andrew, maybe I've missed something, but has *any* this actually been tested
on orbit? If so, would you mind identifying even _one_ Space Tether/Orbital
Sling in operation today? I thought this was all just drawing-board stuff..

Cameron:-)

Of all the exotic means of space transportation,
rotating space tethers are the most popular.
Tethers may be the most popular for nasa/institutional Big LEO systems but
not for CATS people. We want something doable by smaller corporations.
Something like -- SpaceShip1.
^
//^\\
~~~ near space elevator ~~~~
~~~members.aol.com/beanstalkr/~~~

(Allen Meece) wrote in message ...
Of all the exotic means of space transportation,
rotating space tethers are the most popular.
Tethers may be the most popular for nasa/institutional Big LEO systems but
not for CATS people. We want something doable by smaller corporations.
Something like -- SpaceShip1.

From what I can tell, 'corporate' interests aren't interested in
tethers either.

Query - what's the max level of investment that CATS people would
consider 'doable' by smaller corporations? What's the cut-off? Or is
it an attitutde on the behalf of the corporation in questions?

~er

Allen Meece wrote:
Tethers may be the most popular for nasa/institutional Big LEO
systems but not for CATS people. We want something doable by smaller
corporations. Something like -- SpaceShip1.

Speaking of SS1, does anyone have a guesstimate as to just how many
folks will be escending upon Mojave for June 21st?

rick jones
--
The computing industry isn't as much a game of "Follow The Leader" as
it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose."
- Rick Jones
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...

(Allen Meece) wrote in message ...
Of all the exotic means of space transportation,
rotating space tethers are the most popular.
Tethers may be the most popular for nasa/institutional Big LEO systems but
not for CATS people. We want something doable by smaller corporations.
Something like -- SpaceShip1.
^
//^\\
~~~ near space elevator ~~~~
~~~members.aol.com/beanstalkr/~~~

Well, if you want cheap, reliable and tested, you're talking about
modifying existing hardware. I was very impressed with the DC-X for
this reason. While I believe the SSTO-concepts were misguided at the
level of funding they received, I do believe the approach of taking
well proven high-performance engines that are in production and using
them to good advantage.

To this end I offer the following -

A seven element launcher built around a single RL-10 in each element.
Each of these elements are similar and they are arrayed as follows

(1) (2)
(3) (4) (5)
(6) (7)

With propellant flowing from

1 to 3
6 to 3
3 to 4
2 to 5
7 to 5
5 to 4

So, at launch all engines are firing and 1,2,5,6 are drained as the
'first stage'.

When these are empty they are dropped, they slow, and when travelling
subsonically, they deploy glider wings as in a cruise missile - or
perhaps a parachute. They re-enter downrange with no attempt to
return to the launch center. At their down-range entry point there
loiters a recovery aircraft. Thse craft snag the gliders - as did the
old discovery recovery craft did with camera film - and tow them back
to the launch center. There they are released to come to a gentle
horizontal landing at an airstrip associated with the launch center.
There they are refurbed and reloaded and relaunched.

The 'second stage' consists of tanks 3 and 5 - which are drained after
the first stage is dropped. This carries the vehicle until they are
dry. they are then dropped, they re-enter downrange, slow, and deploy
glider wings once subsonic speeds are reached. They are snagged by
recover aircraft downrange and are towed back to the launch center as
well.

The 'third stage' consists of tank 4 with the payload capsule atop.
This stage puts the payload into an orbit with perigee at Earth's
surface and apogee at orbital height -say 200 miles. The capsule has
a kick stage (engine to be determined) which circularizes the orbit
and released the payload. Meanwhile, tank 4 re-enters and is
recovered as in the other six tanks.

The orbiting kick stage is deorbited by the same kick stage engine
after it releases its payload. This stage is recovered by parachute
after a ballistic re-entry. It lands softly using its kick stage once
it cuts loose of the parachute. Since this stage is in orbit it can
come down at an open space near the launch center for a vertical
touchdown once its orbit brings it back over the launch center - which
could be a few days at most.

The payload is released from the carrier capsule and may have an upper
stage that is disposed of - especially if it is to carry a spacecraft
to MEO, GEO, or beyond!

A rough estimate of performance can be attained after examining the
engine performance and estimating other factors;

http://www.astronautix.com/engines/rl10a3a.htm

7480 kg Thrust
1.3 Gee Lift off
5753.84 kg Vehicle Element
0.12 Structural Fraction
690.46 kg Element Structure
5063.38 kg Element Propellant
400 Isp

2500 kg Payload

7 Elements At lift off so; 4 elements feeding engines

42776.92 kg GLOW
20253.53 kg Stage 1 propellant
0.473468801 u1
2519.594746 m/sec Stage 1

3 elements remain fed by 2 elements

19761.53846 kg Stage 2
10126.76923 kg Stage 2 propellant
0.512448424 u2
2821.714923 m/sec Stage 2
5341.309669 m/sec Stage 1+2

1 element remains feeding itself

8253.846154 kg Stage 3
5063.384615 kg Stage 3 propellant
0.613457596 u
3733.617825 m/sec Stage 3
9074.927494 m/sec Stage 1+2+3

2.5 metric tons is around 5,500 lbs... not too shabby.

The RL10 engine costs around $7 million. There have been versions
made that have been designed for low altitude operation (DC-X), there
have been versions that have been designed for low and high altitude
operation and I believe there have been versions designed for
aerospike type operations

http://www.yarchive.net/space/rocket/rl10.html

The RL10 is restartable, has a long firing life. At least 25 launches
would be possible without much trouble. As many as 75 may be doable
without a major upgrade.

A vehicle should cost around $50 million for engines and perhaps
another $100 million for airframe, and all the rest. A test program
can be started with a single element after spending only $25 million
of the total. As elements are added speeds can be increased. Add
another $15 million to develop the orbital capsule - and you have a
system costing $165 million.

For the cost of three Delta rockets you could have spare elements
built to help with turn around.

Also note, a reusable is more reliable than a throw-away. So, this is
important to insurance rates and total mission cost.

At a cost of $55 million per launch this system should be competitive
with a 5,500 lb payload.

Okay, so we can see the following;

$240 million - initial outlay - 3 year development cycle

With 1 flight per week for the system, and a recurring cost of $5
million per launch (looking at propellant, services, recovery costs,
refurb costs, etc.) we have $50 million gross margin per flight.

At 50 flights per year this system would earn $2.5 billion gross
margin per year - and each system would last about a year and a half -
earning $3.75 billion over its life cycle.

Of course, once you began booking flights, you'd order new reusable
elements to replace the worn out ones. You'd also research ways to
extend the life cycle of each element.

But, for the early investors, who might capture half the gross margin,
this would return $1.875 billion over four years for a $0.24 billion
investment. Providing a rate of return of 67% !!!

This rate of return could be made higher by use of bank financing.
That is, risk capital would be needed in the early stages and not
needed later on as critical mission elements were proved.

The DC-X was built and flown for less than $60 million. A few
elements could be built and flown for $60 million - and even place
stuff into orbit - check it out.

7480 kg Thrust
1.3 Gee Lift off
5753.84 Vehicle Element
0.12 Structural Fraction
690.461 kg Element Structure
5063.38 kg Element Propellant
400 Isp

300 kg Payload

Two Elements Fired Serially - with cross feeding

11807.69231 kg GLOW
5063.384615 kg Stage 1 propellant
0.428820847 u1
2199.885691 m/sec Stage 1

6053.846154 kg Stage 2
5063.384615 kg Stage 2 propellant
0.83639136 u2
7110.772149 m/sec Stage 2
9310.65784 m/sec Stage 1+2

This might be worth $10 million per launch, and this would provide
revenue as well as proof of concept. One launch per week would gen up
$520 million per year. Launc costs would be $3 million though. Thus,
profits might be down in the $5 million per launch range. This would
net $260 million per year - which with a good sales force and strong
sales, could be leveraged by well respected management - to finish the
development and construction program.

This would also help the US contain missile proliferation. If a
low-cost RLV of the type described here were operational by a US based
firm, it would undercut the rationale others in other nations have (as
in Korea) for building an expendable launch vehicle.

A single element could be used as a recoverable sounding rocket that
would cost perhaps $3 million per launch - but net only $1 million or
so. Again, it would put the company in business - even though the
sweet spot of operations with this vehicle would be as a 7 element
launcher.

A 3 element launcher could also be considered. This would be 3,4,5
configuration launched from the ground;

7480 kg
1.3 Gee Lift off
5753.846154 Vehicle
0.12 Fraction
690.4615385 Structure
5063.384615 Propellant
400 Isp
700 kg Payload
17961.53846 kg GLOW
10126.76923 kg Stage 1 propellant
0.563802998 u1
3258.909578 m/sec Stage 1

6453.846154 kg Stage 2
5063.384615 kg Stage 2 propellant
0.784553039 u2
6029.63917 m/sec Stage 2
9288.548748 m/sec Stage 1+2


Which would put 700 kg into the same orbit as the Space Shuttle.

This might cost $20 million with another $3 million for launch costs.
This would net $17 million per launch and 50 per year would gen up
$850 million in gross margins. Again not too shabby.

1 element recoverable sounding rocket - $5 million
2 element recoverable launcher - 300 kg LEO - $10 million
3 element recoverable launcher - 700 kg LEO - $20 million
7 element recoverable launcher - 2,500 kg LEO - $55 million

All with the development of a common cross-fed element costing $60
million to develop - and boot-strapped from there.

A 3-engine per element system would triple the size and payload (and
cost) - but once one had experience with the smaller system, then the
larger system should be supportable. 900 kg, 2,100 kg, 7,500 kg...

And then, if demand existed - we could use SSME per element systems -
which would be 30x bigger than the original one;

9,000 kg, 21,000 kg, and 75,000 kg...

Which would pretty much be a low cost manned space system.

Then, if demand existed we could use 7 SSME and something the size of
an ET per element - which would make things 7x bigger still...

63,000 kg, 147,000 kg, 525,000 kg

Which would pretty much be a low cost powersat launcher, tether
launcher, place manned bases on the moon, manned bases on Mars, and so
forth...

Rick Jones wrote in message ...


Speaking of SS1, does anyone have a guesstimate as to just how many
folks will be escending upon Mojave for June 21st?

rick jones

We're going. From Green Bay and Tampa Bay - anyone else going?

Of course the next question is - does anyone know what frequencies
they are (or have been) using for the chase aircraft and space ship
operations??

Joann Evans wrote in message ...
william mook wrote:

This would also help the US contain missile proliferation. If a
low-cost RLV of the type described here were operational by a US based
firm, it would undercut the rationale others in other nations have (as
in Korea) for building an expendable launch vehicle.

As a commercial satellite launcher for world markets, yes. Some
nations who can't build (or buy) RLVs will still look at ELVs to
maintain an independent launching capability, however.

And of course (espically in Korea's case), they will still want ELVs
as medium and long range weapons. The fact that the other guy operates a
fleet of RLVs won't affect that. (Except perhaps to the extent that he
knows that the other guy can get someone up there for recon on short
notice.)


The ability to orbit a payload with a rocket means that same rocket
can be adapted to send a payload to any point on Earth. Suborbital
flight is easier than orbital flight. The US used space as a means to
pay for the development of ICBMS and so did the USSR. So did every
nation who has long range missiles. That's why we have ELVs and not
RLVs. Movement toward RLVs will remove the connection between weapons
systems and space launchers. It will clarify things and give us a
sound basis on which to destroy launcher activity as soon as they're
detected. This won't happen right away for the reasons you state.
But, I can imagine a day when the US, or the collective power of a
group of nations along with the US, will destroy any ELV capacity at
first detection, since it is in effect a gun pointed at the US and its
allies - no matter what is said about it.

Joann Evans wrote in message ...
william mook wrote:

This would also help the US contain missile proliferation. If a
low-cost RLV of the type described here were operational by a US based
firm, it would undercut the rationale others in other nations have (as
in Korea) for building an expendable launch vehicle.

As a commercial satellite launcher for world markets, yes. Some
nations who can't build (or buy) RLVs will still look at ELVs to
maintain an independent launching capability, however.

Yes, absolutely. But, their motives will be clear to everyone, which
will make things easier for our State Department.


And of course (espically in Korea's case), they will still want ELVs
as medium and long range weapons.

But they won't have the fig leaf of space launch development. That's
the point. They will clearly be developing weapons systems to
threaten us and any coalation that we can assemble who is similarly
threatned. Again, this makes things easier geopolitically for the US
to contain missile proliferation.

The fact that the other guy operates a
fleet of RLVs won't affect that. (Except perhaps to the extent that he
knows that the other guy can get someone up there for recon on short
notice.)

Well, there are tactical issues and there are strategic issues.
You've got the tactical right. The strategic you are ignoring.
Consider a world where no RLVs exist and everyone still uses ELVs.
Any nation can build an ELV and say they're doing so to become space
capable. Its not as clear in this environment that they're building
weapons systems.

Now, consider a world where ELVs are a technology of the past and
everyone's using RLVs. Those who make, maintain, and operate the
RLVs, lack the capacity to mass produce the components on a scale
needed to create threatening weapons systems. In fact, RLV
manufacturers can be controlled in a way that still permits them to
operate, but also allows them to demonstrate through inspection and
whatnot that their systems are incapable of being converted to
long-range missiles. In such an environment, someone who set up an
assembly line to produce hundreds of ELVs would have a very hard time
of it geopolitically. They'd be asked what with all the aid and
incentives given by the US and its allies, why they chose the ELV
route? There would be a very clear sense of international threat and
as a result a very high probability of effective action to shut the
ELV system down - either through negotation and cooperation - or
through decisive limited military intervention - dropping a set of
precision guided tungsten KKV rounds from orbit onto the plant.

william mook wrote:

Joann Evans wrote in message ...
william mook wrote:

This would also help the US contain missile proliferation. If a
low-cost RLV of the type described here were operational by a US based
firm, it would undercut the rationale others in other nations have (as
in Korea) for building an expendable launch vehicle.

As a commercial satellite launcher for world markets, yes. Some
nations who can't build (or buy) RLVs will still look at ELVs to
maintain an independent launching capability, however.

And of course (espically in Korea's case), they will still want ELVs
as medium and long range weapons. The fact that the other guy operates a
fleet of RLVs won't affect that. (Except perhaps to the extent that he
knows that the other guy can get someone up there for recon on short
notice.)

The ability to orbit a payload with a rocket means that same rocket
can be adapted to send a payload to any point on Earth. Suborbital
flight is easier than orbital flight. The US used space as a means to
pay for the development of ICBMS and so did the USSR. So did every
nation who has long range missiles. That's why we have ELVs and not
RLVs. Movement toward RLVs will remove the connection between weapons
systems and space launchers.

Thhat distinction is already present. Aside from the fact that many
satellite ELVs are descended from ballistic missile weapons (such as
Atlas, Titan [Thor]Delta) and the Soyuz launcher) others (from Pegasus
to Saturn) never were employed as weapons.

It will clarify things and give us a
sound basis on which to destroy launcher activity as soon as they're
detected.

Not all ELVs are weapons, not all RLVs will be civil/commercial.

And even if not carrying weapons, they may still have military value.
Again and espically for reconnisance. Having humans present doesn't
change the equation. Not all pilotless aircraft are cruise missiles, for
example.


This won't happen right away for the reasons you state.
But, I can imagine a day when the US, or the collective power of a
group of nations along with the US,

Who decides? Who do you trust? Who trusts us?

will destroy any ELV capacity at
first detection, since it is in effect a gun pointed at the US and its
allies - no matter what is said about it.

At what threshold? Is high-power Amateur Rocketry okay? Sounding
rockets? Depending on how close your adversary is (remember the limits
on Iraq misiles?), some fairly small rockets are major threats. What's a
tactical weapon from the US-Russia point of view, is a strategic weapon
to India-Pakastan.

All that sounds like risking an act of war. (which might be carried
out by non-missile means) Or at least either encouraging clandestine
rocket development, or the legal develpopment/aquisition of RLVs and
modifying them for weapons.

--

You know what to remove, to reply....

william mook wrote:

Joann Evans wrote in message ...
william mook wrote:

This would also help the US contain missile proliferation. If a
low-cost RLV of the type described here were operational by a US based
firm, it would undercut the rationale others in other nations have (as
in Korea) for building an expendable launch vehicle.

As a commercial satellite launcher for world markets, yes. Some
nations who can't build (or buy) RLVs will still look at ELVs to
maintain an independent launching capability, however.

Yes, absolutely. But, their motives will be clear to everyone, which
will make things easier for our State Department.


And of course (espically in Korea's case), they will still want ELVs
as medium and long range weapons.

But they won't have the fig leaf of space launch development. That's
the point. They will clearly be developing weapons systems to
threaten us and any coalation that we can assemble who is similarly
threatned. Again, this makes things easier geopolitically for the US
to contain missile proliferation.

The fact that the other guy operates a
fleet of RLVs won't affect that. (Except perhaps to the extent that he
knows that the other guy can get someone up there for recon on short
notice.)

Well, there are tactical issues and there are strategic issues.
You've got the tactical right. The strategic you are ignoring.

As noted in the other message, that distinction depends partly on who
and where you are.

Consider a world where no RLVs exist and everyone still uses ELVs.
Any nation can build an ELV and say they're doing so to become space
capable. Its not as clear in this environment that they're building
weapons systems.

Now, consider a world where ELVs are a technology of the past and
everyone's using RLVs. Those who make, maintain, and operate the
RLVs, lack the capacity to mass produce the components on a scale
needed to create threatening weapons systems. In fact, RLV
manufacturers can be controlled in a way that still permits them to
operate, but also allows them to demonstrate through inspection and
whatnot that their systems are incapable of being converted to
long-range missiles.

And what happens once they leave the manufacturer's hands? We want
RLVs to ultimately be as common as, say, wide bodied jets. What stops
someone from modifying one of those for some military purpose? (Some
wanted the US to use modified 747s as long range cruise missile
carriers, rather than develop the B-1, for example.)

You can't really stop someone from customizing one of these. And if
they're willing to clandestinely pre-place nukes (or other weapons) in
orbit, it doesn't even take modification. Then you have the added issue
of demanding satellite inspection for everyone, when anyone can launch
anything on an RLV.

In such an environment, someone who set up an
assembly line to produce hundreds of ELVs would have a very hard time
of it geopolitically.

Mot everyone will care.

They'd be asked what with all the aid and
incentives given by the US and its allies, why they chose the ELV
route? There would be a very clear sense of international threat and
as a result a very high probability of effective action to shut the
ELV system down - either through negotation and cooperation - or
through decisive limited military intervention - dropping a set of
precision guided tungsten KKV rounds from orbit onto the plant.

Hmmm...acting pre-emptively has a bad reputation these days. and
similary, your intel had better be good.

--

You know what to remove, to reply....