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November 30, 2007

A review my favorite space launch and propulsion systems

Accelerating future had reviewed systems for getting into space in 2006

I had covered the EM drive but is definitely one of the long shots with a lot of unknowns in the science (ie. I seriously doubt that it will work).

My preferences are for:


Bussard IEC fusion earth to orbit spaceship. Credit: Tom Ligon and EMC2fusion

Fusion propulsion if Bussard IEC fusion or Trialpha energy colliding beam fusion or laser fusion or Z pinch fusion work. The fusion systems would have a superior version for getting from ground to orbit. However, as we have experienced fusion technology could disappoint and take longer than we would like to develop.


Laser launch concept


Laser mirror concept for station keeping. For laser mirror propulsion, there would be an array of large (100+ kw solid state) lasers firing at one of the mirrors and the other non-moving mirror would be on the moon or the earth.

Mirror Laser array launches Solid state high power lasers are progressing far faster in power and efficiency than many people realize. I think convergence of technology could make this happen far quicker than many would expect. It would bring the cost of launches down to about the cost of electricity (even better with mirror systems)



I would really like it if people would become rational and allow nuclear rocket launches. The liberty ship is one that could luanch 1000 tons at a go and would not release radiation into the atmosphere I think nuclear rocket systems would be safer than chemical and space planes because there is so much safety margin to play with.

Project Orion definitely made sense. It would be cheaper than the space elevator. The launch cost for the largest Orions was 5 cents per pound (11 cent/kg) to Earth orbit in 1958 dollars. In 2005 dollars, the cost would be 32 cents/lb or 70 cents.


Minimag Orion and other external nuclear pulse propulsion systems One thing to note is the pussy footing around with sub-critical explosions is stupid if we have technology for achieving 10+% of the speed of light and have 20+GW laser arrays. 10 kiloton TNT equivalent bombs would be like hand grenades.

What seems like a cheap system for bringing the cost of gravity hardened systems and cargo into space for less than 25% of current costs is ram accelerators (big guns)

nuclear electric rocket
A nuclear powered vasimr might look more like this nuclear electric vehicle. Replace the MPD thrusters with vasimr engines, replace the Brayton units with advanced thermoelectric devices.


Image of a vasimr rocket

Nuclear powered Vasimr for getting around from orbit to other places

My issues with the space elevator is that it will take longer than I would like to make it happen. It brings the goal of bringing the cost of getting to space to approach the cost of the electricity to lift mass to the right height. The mirror laser array system seems like something that could come together faster than the space elevator. I also prefer a longer space pier over the space elevator. However, I still support the space elevator project because other approaches might have development delays as well. Capturing mind share and imagination are useful things for making something happen.

high altitude winds

I am also concerned about the performance of the recent contest climbers when they could not climb because of wind. The actual climbers will have to go through high winds at higher altitudes. I do not think this is a show stopper but a possible show delayer.

J Storr Hall's space pier seems like a better approach than the space elevator. One design would lift 10-ton payloads up a 100 km elevator and then accelerating it to 8.2 km/s would only consume about 5,000 US dollars (USD) worth of electricity, working out to about half a dollar per kilogram.

A description of the space pier is here.


The space pier is 100 kilometers tall and 300 kilometers long.

FURTHER READING
Island one survey of earth to orbit launch systems

Space fountain at wikipedia

Launch loop at wikipedia

Orbital rings at wikipedia

7 comments:

Dezakin said...

You might want to have a look at skylon actually for a very plausible SSTO without utilizing esoteric technology.

bw said...

I have looked at Skylon.
http://en.wikipedia.org/wiki/Skylon

http://en.wikipedia.org/wiki/SABRE

I do like it. I am not sure why it does not get better funding.

Jim Baerg said...

The 'space pier' has some resemblances to the launch loop.
http://www.launchloop.com/
However, the launch loop requires less in the way of unobtanium. The launch loop acceleration path is held up by centrifugal force of moving parts of the system rather than by towers made of materials with enormous compressive strength.

bw said...

I had seen the smaller launch ring

http://advancednano.blogspot.com/2007/08/cheaper-space-launch-500kg-or-less-ram.html
http://www.launchpnt.com/Space_Launch.32.0.html

but not the larger launchloop.

The launchloop looks good. I will take a closer look at it.

bw said...

As large as the space pier is, the launch loop is a lot bigger. It also has more complicated track parts throughout.

capital costs for magnetic levitiation trains are $40 - $60 million per dual-track mile are typical for simple, longer routes and up to $80 - $100 million per dual-track mile are typical for shorter, more complex routes.

Personal skypod magnetic track has claimed that it will only cost
one million dollars per mile

The launchloop is for heavier and faster objects, so it will be at higher end of the range. 100 million per mile. 4000 miles. $400 billion.

We need to lower the cost of magnetic levitation

I was hoping to sidestep the costs of true magnetic rail levitation costs by trying to enhance a superconducting system to the point it could ground launch. I do not know if this will work.

Most of the space pier has simpler construction (assuming the necessary materials are available).

bw said...

I will note that spending 400 billion to 1 trillion on a launchloop that worked would be a better use of funds than 150 billion for a spaceplane.

Thomas Gail Haws said...

I agree that a launch loop looks better. It's massive, but not exotic.