Re: Modest Proposal - Common Interplanetary Booster

On Sep 3, 7:31 am, Ian Parker <ianpark...@xxxxxxxxx> wrote:
I feel that we should concentrate on low cost to LEO for the following
reason. Once you are in space you can use the highly efficient ion
propusion motor.

Recall, that high specific impulse on orbit, translates to more
payload on high orbit for a given launcher size.

Given our current capabilities in space, apogee kick motors and
perigess kick motors are nearly all solid propellant. They are also
all expendable. This means they're low performing and high cost.

I am proposing here that they be replaced with a reusable hydrogen/
oxygen system that is more than twice as efficient when compare to
solids, and less than 1/50th the cost when compared to expendables..

These two improvements increase payloads to deep space and lowers
their cost already.

Now, increasing specific impulse beyond that of hydrogen/oxygen and
lowering costs below reusable chemical propellants will occur along
the lines I've described elsewhere. It will be done as part of a
continuing chain of commercial development.

Low cost to LEO is achieved by building fully reusable systems,
operating from adequately maintained infrastructure, having sufficient
operating rates and process automation to end the need for standing
armies of technicians to fly them.

Anyone who has paid a premium for a swiss watch knows that smaller can
mean more expensive - depending on the details. An appropriately
sized vehicle can do much to reduce costs as well.

Yet, there is something to be said about smaller systems built around
existing engine sets with modern airframes and avionics.

The smallest vehicle I have analyzed involves building an annular
aerospike nozzle around an Pratt&Whitney RL-10 pumpset. Last time I
looked this it cost $5 million. A flight element, when you include
avionics and airframe, cost $12 million for the flight article.

The engine is capable of 4.5 km/sec exhaust speed and 20,000 lbs
thrust. It is attached to a flight element that has 15,384 pounds
mass, carrying 14,000 pounds of propellant - massing 1,384 pounds
emtpy - using SSTO technology

This vehicle with 750 pounds payload,is capable of attaining orbit.
More importantly it is capable of being tested through all flight
regimes before being put into service.

Ganging together 3 flight elements, the two outboard elements
operating as first stage, feeding propellant to the central element,
which operates as second stage, along the lines already described for
the larger vehicle, puts 4,500 pounds into orbit.

The vehicle masses 50,000 pounds a lift off and produces 60,000 pounds
of thrust. When the two outboard elements separate, the system is
flying at 5.47 km/sec - less air and gravity drag losses. The upper
stage adds another 3.63 km/sec - again without air and gravity drag
losses.

This system costs $36 to build, another $14 million for non-recurring
engineering charges. Add another $50 million for launch center and
operations center. This is $100 million - and it the minimum you can
do.

A 4,500 pound payload is about the size of a Gemini capsule or Soyuz
orbital module. With modern avionics and structures, and best
engineering practices, it should be possible to put 3 to 5 astronauts
aboard - if that's the direction you want to go.

The piloted stage - is likely to add another $100 million to the
overall costs - and add another $100 million to build a fleet of 3
launchers for a reasonable flight rate of once per month trending with
learning curve effects to 2 per month.

So, we're talking $300 million minimum cost - in this sort of program
- to prove out the various ideas I'm putting forth here.

Putting in a couple of expendable kick stages like TE-473 at perigee
and TE-416 at apogee - both from Thiokol - gives you a capacity to
take 500 pounds or so to GEO - at several million dollars added cost
per launch.

In short, for $300 million gets you into the launch business - at the
same scale most others are in these days.

But with the exception of expendable upper stages, you've dramatically
lowered the launch costs. A flight rate of one launch per month is
maintained, and about $60 million per year is earned - $5 million per
flight - trending to $120 million per year for your $300 million
invested.

Insurance costs are extra.

Increasing the size of the vehicle is easily achieved by increasing
the number of pumpsets per aeropike engine. Six to eight seems to be
the practical limit - with 160,000 pounds thrust topping out the
system using these pumps. This is about 1/70th the size of the M1
based system I've described elsewhere and miniscule compared to the
super-heavies needed to develop the moon and mars and asteroids
industrially.

Since payload to orbit scales with launch weight, a 8 pump system
launches 31,500 pounds into LEO - and vehicle elements are twice the
linear dimension of the 'starter rocket'.

Costs are 6x larger as well. We're talking a $1.8 billion program
now. But, we can use the smaller vehicles as high energy reusable
upper stages!

Two of the flight elements described above can carried aloft the
larger system, fired in parallel to put 9,000 pounds into GEO with
recovery of ALL stages.

Alternatively, the two flight elements can be fired in series, and
place 4,500 pounds on the moon and return it to Earth. Also, 4,500
pounds can be landed on Mars and returned to Earth.

This achieved with RL-10 pumps configured as described.

This replicates what we're doing now in space, and doesn't
substantially advance the art - though it does apply some technology
that has been developed over the past 20 years.

Once I have the money to treat rockets like sportscars or race planes,
I'd build the following $30 million sportscar;

Two RL-10 pumpsets feeding an annular aerospike engine can be tweaked
to produce 44,000 pounds of thrust. This is 1/500th the thrust of the
ROMBUS

http://www.astronautix.com/lvs/rombus.htm

Cutting all the numbers back by 500 - and the dimensions back by the
cube root of 500 - you have micro-m-bus haha..

Mirco-moon bus.

LEO Payload: 1,980 lb to: 185 km Orbit. at: 28.00 degrees.
Liftoff Thrust: 36,000 lbf
Total Mass: 28,000 lbf
Core Diameter: 9.82 ft
Total Length: 12 ft

Eight tanks,

Gross Mass 575 lbs
Empty Mass 80 lbs
Length: 12.61 ft
Diameter: 3.14 ft
Propellants: Lox/LH2.

Stage1: 1 x Rombus.

Gross Mass: 22,500 lbs
Empty Mass: 1,350 lbs
Motor: 1 x Plug-Nozzle Rombus.
Thrust (vac): 45,800 lbf.
Isp: 455 sec.
Burn time: 215 sec.
Length: 12 ft.
Diameter: 6.55 ft
Propellants: Lox/LH2.

This puts 1,980 pounds into orbit - this is a 1 person capsule -
integrated atop the micro-Rombus vehicle.

The interesting thing is that any launcher that can put 22,000 pounds
of propellant on orbit next to the micro-rombus, can cause it to carry
out the mission profiles described in the associated missions

Project Selena,
Project Deimos

- all done on a micro scale.

http://www.astronautix.com/craft/proelena.htm
http://www.astronautix.com/craft/proeimos.htm

The 3.14 ft diameter 12.61 ft long hydrogen tanks are a bit small for
habitats - perhaps individual sleeping compartments on the moon or
mars.

The vehicle that is 8x larger than the minimum vehicle - the one that
puts up 31,200 pounds - is fully capable of supporting the micro-
rombus.

So, you either put it as the upper stage aboard the vehicle, or you
launch both separately and refuel on orbit. The latter is useful if
the launcher is not man-rated.

These smaller systems as you can see do not lower the cost to LEO on a
per kg basis, as far as the larger systems. Nor do they increase the
mass flow rate to orbit to absorb the increase in demand caused by
lower costs.


No, I will correct myself LEO and high energy weight solar systems.

As I said, putting a reusable hydrogen oxygen kick stage to work is a
vast improvement over current art and the addition of laser
propulsion, (thermal, detonation, electric, light sail) is premature
until laser costs are in line with other rocket costs.

If
an objective is SSP what will be needed is just that. Let us think in
terms of a squae kilometer of aluminium 1 micron thick. Weight 2.7T.
This can be used for reflectors. Potentially 2GW is falling on that
sqare kililometer. OK you will need silicon cells struts to give some
degree of mechanical stability. You will only get a limited efficiency
too.

Use gas pressure - see Echo -

http://www.astronautix.com/craft/echo.htm

a transparent top *** and a reflective back *** - heating is an
issue - this is starting to sound like my low mass powersat.

This will be developed after laser power sats are operating - when it
makes sense to do so. The effect will be to raise the payload to
high orbit by a factor of 2 to 3.

The problem is the thrust to weight versus power and mission times.

If you could get 500MW for 10 tons you would be well placed not only
to have a good ion drive system, but also a stepping stone to SSP.

Making a lightweight laser powersat along the lines I've described
elsewhere, and launching it aboard a large launcher - provides a means
to directly enter a powersat program where the launcher and satellite
and everything else is developed in one program and paid for by power
sales.

To get to LEO only rockets are really feasible.

No, once you have substantial power on orbit, available by laser or
maser beam - you have a variety of rocket propulsion elements to
consider;

laser thermal - 10 km/sec 44.5 MW/tonne
laser detonation - 20 km/sec 89.0 MW/tonn
laser electric - 50 km/sec 222.5 MW/tonne.
laser light sale - 300,000 km/sec 1,470 MW/kg

Reducing oxygen aboard to cover only early ascent, and then relying on
laser thermal rockets to be used at the tail end of launch, and then
switching to laser detonation on the ascent stage, and then, to laser
electric on the orbital stage, provides adequate thrust throughout the
flight cycle, and optimizes vehicle performance so that payload on GEO
per launch is maximized.

This requires the development of a few dozen technologies and the
successful resolution of nearly 100 open issues - AFTER the powersats
are operating.

Putting a powersat program at the tail end of resolving all this - is
just a way of saying you're not going to be doing it anytime soon.


From LEO to wherever
there are a lot of other concepts that should be explored.

I have looked at nearly everything out there, what I propose here is
the first step in the direction I need to go following the success of
my early coal-to-liquid projects. I have sponsored 8 projects around
the world - and intend to do 50 to 60 projects over the next 10
years. Upgrading each of these terrestrial solar arrays with bandgap
matched light sources - provides a means to provide ALL the world's
PRESENT energy supplies from space. This generates $4 trillion per
year - with high margins. Given the EBITDA I've projected for the
system, it will have a market capitalization - assuming no further
fuel price increases - of about $80 trillion. 1/3 of that will be
owned by me. This will provide sufficient capital to acquire all the
space launch assets of the planet and organize them to do something
interesting in space. This will include;

1) global wireless internet - telerobotics
2) global beamed power from space
3) industrial development of the moon and mars
4) capture of NEAs and industrial development on Earth orbit
5) telerobotic factory satellites
6) personal ballistic transport
7) personal spaceship, space home.

Then I will retire.

  - Ian Parker

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