72 M-1 Combustor Aerospike Engine

We start with the engine

The M-1 engine is the largest hydrogen oxygen engine ever conceived.
The M-1 approached 2 million lbf, the injector was large - 42"
diameter feeding a 47" diameter combustor.

So, imagine an aerospike engine consisting of 72 injector/combustor
segments joined in a ring 183 ft in diameter and producing 144 million
lbf thrust. A 183 ft diameter sphere of liquid hydrogen massing 14
million pounds combined with eight smaller tanks nestled below the
larger sphere within a gently tapering cone aeroshell. The eight
tanks each 65 ft in diameter hold a grand total of 84.5 million pounds
of liquid oxygen.

This is the first stage.

The second stage consists of a smaller version of the first stage. It
has only 15 injector/combustor segments joined in a ring only 37 ft in
diameter and produces 30 million lbf thrust. A 37 ft diameter sphere
of liquid hydrogen carrying 2.8 million pounds sits atop the smaller
engine and beneath that larger sphere another eight smaller spheres
each 13 ft in diameter hold a grand total of 17 million pounds of
liquid oxygen.

This is the second stage.

The payload is housed in a 37 ft diameter cylinder that is 120 ft long
capped by a 30 ft tall cone and carries 9 million pounds of payload to
orbit within. In this way 9 million pounds is carried through an
ideal delta-vee of 20,750 mph to attain an actual delta-vee of 16,000
mph after air-drag and gravity losses.

This is the payload capacity.

The booster rocket re-enters tail first using its aerospike as a heat
shield. Then re-starting a fraction of the engines to land tail first
at a second launch center down range from the first. A total of three
launch centers encircle the Earth to maintain a fleet of 9 launchers.
A vehicle operates once a day from each of the launch centers. After
three launches, a booster returns to its point of origin. The
orbiter descends and lands where it originated from after deploying
its 9 million pound payload on orbit. In this way 27 million pounds
of payload are placed on orbit every day.

A 22 GW high temperature nuclear reactor at each of the three launch
centers turns 20 million gallons of sea water into sufficient hydrogen
and oxygen to fuel the great ships and power the launch center and the
industrial base that supports it.


On orbit

Five NERVA rocket engines, producing 375,000 lbf thrust together -
with one bimodal system capable of producing 100 MW on orbit - once
thermal radiators are deployed - using empty hydrogen tank as
radiator.

They sit beneath an interplanetary stage that consists of three tanks
of liquid hydrogen each 37 ft in diameter. The 8.4 million pound of
propellant with 600,000 lbs tankage and engine - 1/48th gee when
carrying another 9 million pound payload- and when full - which
increases to 1/24th gee when empty. The system can impart an
additional 11,722 mph to 9 million pounds of payload. Enough to send
9 million pounds to the moon, or Mars, or GEO.

Beyond orbit

The Moon

The booster executes a lunar free return trajectory and returns to
Earth to re-enter and land using chemical rocket engines. The system
is refurbished and reused. Since it takes 9 days for this journey and
another 9 days to process each stage, a total of 20 stages are in
inventory to support this lunar operation.

The 9 million pound payload consists of two 37 ft hydrogen tanks and a
cluster of 25 NERVA engines - carrying another 3 million pounds to the
lunar surface. The vehicle soft lands on the surface and deposits the
3 million pounds of payload. Without refueling, it may accept 1
million pounds of material to return to Earth. In most typical usage,
2,200 people per day cycle to and from the moon, along with 1,000 tons
of materiel. Since water and hence oxygen and hydrogen are available
on the moon, using a space borne variation of the 22 GW nuclear
reactor, enough materiel is brought by this operation to support 3.6
million people on the lunar surface.

Mars

The interplanetary stage separates and returns to Earth along a 2 year
cycling orbit. At Earth the stage re-enters the Earth's atmosphere
and lands using chemical propellants in a manner very similar to that
used by the Lunar stage. A salvo of 9 stages are launched every 2.15
years - and returned in 2 years - to be reprocessed for the next
synodic period. A total of 10 stages are used for this purpose.

A 9 million pound payload along with a nearly empty upper stage
executes an aerobraking maneuver after separating from the
interplanetary stage. Chemical rockets are used to touchdown after
entry into the Martian atmosphere. 9 million pounds of payload are
off loaded from each arriving vehicle. A small nuclear reactor
processes martian air to process it into water and then to hydrogen
and oxygen to refuel the upper stage with 19.7 million pounds of
propellant. Another 2 million pounds of payload and 2,200 people are
loaded aboard after refueling - which takes an entire synodic period -
and the vehicle is launched off Mars to dock with the departing
interplanetary stage.

With 9 vehicles 19,800 people are cycled to and from Mars every 2.15
years and 72 million pounds of materials are brought every 2.15
years. A total of 168,000 people may be supported in this way on
Mars - assuming they get oxygen and water from the Martian
environment.

Establishing a large 22 GW nuclear reactor on Mars provides an
expansion of the industrial base there and allows 30 ships to arrive
every 2.15 years - allowing 571,000 people to live on Mars at a high
standard consuming 220 lbs of material per person per year made on
Earth with the balance made on Mars.

This is what was possible to do in the 1960s with spending at 3x the
1966 peak between 1966 and 1996. It involved no unknown technologies
or radical improvements beyond the technology developed up to that
time.

Radical improvements beyond this vision are possible in engine
performance. This includes;

(1) laser beam propulsion;
(2) nuclear pulse propulsion;
(3) gas core nuclear pulse propulsion;

These are all simultaneously high specific impulse and high thrust.

Other advances include;

(4) MEMS rocket technology
(5) high thrust laser light sail (ultra-reflector technology)

The last requires very large solar pumped laser systems - which appear
to be possible.

A private initiative that takes over the aerospace assets of this
planet and organizes them to solve our energy problems and create a
global wireless hotspot - can actually pay for a development program
that develops assets and resources off-world to solve other resource
problems by mining the asteroids.

Larger Still!

The same lift x7 in a three stage system similar to the one shown here

http://www.scribd.com/doc/30943696/ETDHLRLV

Only 7.751x larger in all dimensions and 59.5x heavier!

By doubling the number of combustors at every position, we have 36
doublets to obtain the same 72 combustors as pairs of combustors
around a ring that's only 99 ft in diameter. This lifts an external
tank looking hydrogen oxygen tank pair that's 108 ft in diameter and
600 ft tall - massing 100,000,000 lbs - with 144,000,000 lbf engine
beneath it. A single SSTO lifts 7,500,000 lbs into orbit. Seven of
these large elements lift 91,600,000 lbs into orbit!

Applied to power satellites this larger system allows a 25 mile
diameter collector to be launched capable of producing 595,000 MW of
power at GEO beaming power from a 3,300 ft diameter emitter to mobile
users on the ground. The Rayleigh Criterion means larger optics on
orbit allow smaller optics on Earth.

Alternatively a satellite pair can be launched consisting of emitter
hardware only that's 2.3 miles across and when one is operating at GEO
and the other operating 2.2 million miles from the Sun beaming energy
to the first one - the pair produces for nearly the same cost as the
concentrator based system over 14,000,000 MW of laser energy -
reducing energy costs further.

Only two pairs of satellites this size are enough to supply all our
energy needs today.

One of these operating a laser light sail can generate 22,000 lbf of
thrust from an efficient mirror! Lifting a 66,000 lb payload at 1/3
gee for 1 year gets it up to 1/3 light speed. Applying the same light
to light sails in the asteroid belt retrieves 170,000 tons per year
without any expenditure of propellant.

A similar satellite orbiting a target star slows the same payload in 1
year and reorganizes that star system at the same rate.

A sail 2200 square feet produces 'lift' of 10 lbs per square foot is
large enough to provide the thrust needed for the missions just
described. Light intensity is 6,360 MW per square foot. A light sail
that is 99.999999% reflective (which have been built) absorbs only 64
Watts per square foot. Radiating this across both sides of the film
32 Watts/sq ft is radiated away in vacuum - which raises the
temperature to a little less than the boiling point of water!

One satellite retrieves 170,000 tons per year from the asteroids.
One satellite dispatches 11 tons per year to nearby stars.

On Oct 19, 11:45*pm, William Mook wrote:
We start with the engine

So, imagine an aerospike engine consisting of 72 injector/combustor
segments joined in a ring 183 ft in diameter and producing 144 million
lbf thrust

Snipped other state derived from Aerospike

You are aware are you not that their a some significant issues still
be resolved with a Aerospike engine for orbital launch. Some say
insurmountable issues but not all are as pessimistic.

Just as one example how would you handle the transonic issues in such
a beast?

On 10/30/2010 8:10 PM, Tulley wrote:

You are aware are you not that their a some significant issues still
be resolved with a Aerospike engine for orbital launch. Some say
insurmountable issues but not all are as pessimistic.

Just as one example how would you handle the transonic issues in such
a beast?

I was quite surprised to see they actually did get one running for the
Air Force's canceled spaceplane program:
http://www.picturetrail.com/sfx/album/view/8379229
It was the AMPS-1:
http://pic100.picturetrail.com/VOL56.../245214005.jpg

Pat