O'Neills vision: Mars instead of moon.

Antius · 2016-10-23 06:18:25

O'Neill's original vision involved installing electromagnetic catapults on the moon and firing lunar materials to a Lagrange point on the moon's orbit. Here they would be used as feedstock for construction of solar power satellites to supply Earth with electrical energy.

Many technical issues remain to be resolved before this scheme can be enacted. My question is, could SPS be produced on Mars or in Mars orbit and transported to Earth orbit? Does Mars offer any advantages over the moon in this capacity?

RobertDyck · 2016-10-23 07:05:05

We have discussed solar power satellites many times. They're a bad idea. Solar panels on the surface of the Earth can produce power, no need for a satellite. Earth has night on average 50% of the time, in summer less than 50%, in winter more. Solar panels don't produce power in dark. Earth also has clouds, and UV is blocked by the ozone layer. Solar panels can convert UV to power too. However, the highest efficiency anyone has ever achieved for microwave power transmission is 30%, and that is over short distance. Geostationary orbit is 36,000km above the surface, power loss is much greater at that distance. So just in terms of efficiency, solar panels on Earth deliver power power to the grid for a given size solar panel. Then there's the issue of safety. If you have a multi-megawatt microwave beam aimed down at Earth, what happens if aim is off just a little bit? You microwave cook an entire city! Or if an aircraft flies through the beam. Then there's cost: maintenance and repairs in space require a spacecraft to fly a technician in a spacesuit, but maintenance on the ground can be done by a guy in normal clothes delivered to the site with a pickup truck. Pickup truck is a lot less expensive than a Space Shuttle or Orion spacecraft.

I'm all for mining precious metals from metallic asteroids, and delivering bullion to Earth. The heat shield and aeroshell to drop the bullion from space can be made with "leftovers" from the asteroid. NASA devised an alloy as a metallic heat shield: Inconel 617. It's mostly nickel-chrome, with a little cobalt, molybdenum, aluminum, carbon. Extracting metal from the asteroid required hydrogen and carbon monoxide, which can be harvested from a carbonaceous chondrite asteroid along with propellant. CO or CO2 brought to the metal asteroid would be source of carbon for the heat shield.

However, solar power satellite is a bad idea.

Void · 2016-10-23 09:59:03

Antius and RobertDyck,

Robert Posted this under Human Missions:
http://msnwllc.com/space-propulsion

The Electrodeless Lorentz Force Thruster
The ELF-250 thruster, funded by the NASA NextSTEP program, utilizes Rotating Magnetic Field (RMF) and pulsed-inductive technologies that promise radical advances in space propulsion. The ELF creates, forms, and accelerates field-reversed plasma toroids to high velocity. It has demonstrated the ability to efficiently utilize complex propellants such as Martian Air, Liquid Water, and Hydrazine . The ELF-250 is a 100 kW class thruster for deep space missions.
The ELF enables a broad range of high-power propulsion missions. Fundamentally, this technology has significantly greater thrust and power densities than any realizable propulsion technology. The ability to operate on in situ propellants will enable very eccentric orbit propulsion, re-fuelable orbital transfer vehicles, deep space return missions, and even direct drag makeup for extremely low orbits. At current power levels, this thruster technology minimizes system mass, size, and cost, while increasing overall mission flexibility. Finally, extending this technology to higher densities and powers that have been demonstrated in the laboratory, there are mission applications in high-altitude, air-breathing, hypersonic flight and beamed-energy upper stage propulsion that are not feasible with traditional technologies. Please see technical publications below for a complete description of experiments, thruster specifications, and results.

More reading from Roberts post:
http://msnwllc.com/propulsion-publications

So, if you could obtain Martian atmosphere to go to asteroids and fetch metals back to Earth, then you might have a viable Martian economy, I would think.

Antius Said:

Many technical issues remain to be resolved before this scheme can be enacted. My question is, could SPS be produced on Mars or in Mars orbit and transported to Earth orbit? Does Mars offer any advantages over the moon in this capacity?

This would come later if at all, but if you built power satellites from materials of Phobos and Demos, you could of course use them for purposes on Mars, with relatively less risk to humans.

But the real payday would be if you could use the satellites to power spacecraft harvesting Martian atmosphere without having to land.
That atmosphere would then allow travel to and from the asteroid belt, and who knows maybe even the Trojans, and the delivery of a payment of metals to Earth to pay for actions on Mars.

Eureka?

Last edited by Void (2016-10-23 10:09:42)

Void · 2016-10-23 10:14:52

Psyche (Just for fun, a metal asteroid)
http://www.space.com/24289-metal-astero … mages.html
http://www.space.com/24288-strange-meta … ssion.html

https://en.wikipedia.org/wiki/16_Psyche

16 Psyche is one of the ten most-massive asteroids in the asteroid belt. It is over 200 kilometers in diameter and contains a little less than 1% of the mass of the entire asteroid belt. It is thought to be the exposed iron core of a protoplanet.[5] It is the most massive metallic M-type asteroid.

http://www.space.com/24284-asteroid-psy … aphic.html

So, a significant magnetic field as well....

Does that indicate that Tom could build his giant machines and have them orbit Psyche and not need that much radiation shielding?

I know of a mine where the iron is so pure that supposedly you can weld to the rock (Actually the Soudan mine).

What if you could dig into this asteroid, and weld parts to the tunnel walls, so creating a very strong habitat?

But of course Mars is the main feature here, but a payday is a big thing as well. We want a payday for the Mars effort.

Hope I have not gone too far with this.

Last edited by Void (2016-10-23 10:28:52)

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#1 2016-10-23 06:18:25

O'Neills vision: Mars instead of moon.

#2 2016-10-23 07:05:05

Re: O'Neills vision: Mars instead of moon.

#3 2016-10-23 09:59:03

Re: O'Neills vision: Mars instead of moon.

#4 2016-10-23 10:14:52

Re: O'Neills vision: Mars instead of moon.

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