Author Topic: Zubrin writes piece advocating mining the moon for propellant  (Read 3372 times)

Offline QuantumG

  • Senior Member
  • *****
  • Posts: 7972
  • Australia
  • Liked: 2672
  • Likes Given: 652
Every space station ever launched has had thrusters on it.
Jeff Bezos has billions to spend on rockets and can go at whatever pace he likes! Wow! What pace is he going at? The slowest possible.

Offline ncb1397

  • Full Member
  • ****
  • Posts: 678
  • Liked: 316
  • Likes Given: 3
Every space station ever launched has had thrusters on it.

Take ISS as an example. ISS is 400 mT and Zarya/Zvezda provide about 10 mT of hypergolic propellant capacity. Less than 100 m/s of orbital maneuvering there. Not enough to go anywhere and meant for station keeping.

Offline QuantumG

  • Senior Member
  • *****
  • Posts: 7972
  • Australia
  • Liked: 2672
  • Likes Given: 652
Take ISS as an example. ISS is 400 mT and Zarya/Zvezda provide about 10 mT of hypergolic propellant capacity. Less than 100 m/s of orbital maneuvering there. Not enough to go anywhere and meant for station keeping.

Which, if you read Robotbeat's post, is exactly his point when it comes to this station. Ya need a tug to move it anywhere.

Jeff Bezos has billions to spend on rockets and can go at whatever pace he likes! Wow! What pace is he going at? The slowest possible.

Offline gbaikie

  • Full Member
  • ****
  • Posts: 1628
  • Liked: 48
  • Likes Given: 5
around the 3 minute mark, he says that if you can refuel a vehicle in orbit it's a very valuable thing to do.

Okay, but so refueling in orbit doesn't really contradict the idea of having your base and propellant manufacturing on the lunar surface, does it? You'd manufacture on the surface, and then send it up to an orbiting depot (lagrange point?) for others to dock with and refuel off of.

I support idea of exploring the Moon, first. Well, actually making a depot in LEO to re-fuel LOX and exploring the Moon, first. I don't support idea of manned spacestation in high earth orbit- unless it's related to using ISS [boosting ISS to higher orbit, so as to keep ISS indefinitely or don't favor de-orbiting ISS] But also don't favor NASA building a lunar base in near term.
I think NASA can explore the Moon without spacestation in high orbit, or a lunar base.

Zurbin says: "If the goal is to build a Moon base, it should be built on the surface of the Moon."

And I don't think the goal should be to build a Moon base, rather I think the goal should to determine whether there is minable water at lunar poles.
After one determines whether there is minable lunar water, and someone is commercially mining it, then one could consider building a Moon base.
I don't want a government "trying to make" lunar water [or iron oxide or whatever] minable.
It would be similar but worse then a government "trying to make" solar panels a viable source of global electricity.
And other than costs, we lack the time to do this.
I want to NASA to explore the Moon, and then immediately thereafter start exploring Mars.
So I want NASA to develop an operational depot in LEO and explore the Moon and be finished within 10 years. If start now, be exploring Mars [manned] by 2027.

It's quite possible that after NASA explores the Moon, no one is actual mining lunar water by 2027, but they would have the results of NASA lunar exploration to determine whether they make the choice of mining lunar water [and get the investment dollars to do it].

NASA lunar exploration would be finding lunar water, and would start and continue with robotic exploration and finish with manned exploration of lunar surface [with lunar sample return being a part of manned lunar exploration]. And depot at LEO refuels LOX for robotic and manned mission to the Moon [and any other robotic mission which going other places other than the Moon].

Purpose of Mars exploration is also not to build a Mars base, the purpose is to determine whether and how future Mars settlement can be viable. Part of this, would also include whether Mars has minable water. The difference between Lunar and Mars minable water is the amount of water which needs to be available at some site. And related to this aspect of quantity of water is the cost to mine it. Roughly the more water needed over a time period [say 10 years] lower to per kg/ton cost of water.
A mars settlement needs a large amount of water and a cheap cost per ton. Say more than million tons and less than $100,000 per ton. With the Moon one needs a site to have about +10,000 tons and cost of about  1/2 million dollars per ton. One doesn't really need lunar water to be less than $500,000 per ton and it help a lot if Martian water was much less than 100,000 per ton and have much more than 1 million tonnes available at one site on Mars.
One can say that the Moon requires the least amount of water, as compared to any other destination in space [Mars, Mercury, and/or space rocks]. And any destination which starts water mining in space requires that one does have to have a large market for rocket fuel [As there is no market at the moment in space].
Or the first year of production of lunar rocket fuel could begin at about 50 tons per year- though one would plan to roughly double production each following year. Or unless there is existing market, one has to start small and grow the market [and you want to grow it fast though one should expect  there will be some kind of limit to it's growth- or somewhere around 1000 tons, it might double every 2 or 3 years [though it could instead, double every 6 months]. Also with lunar water mining you want to start with lunar surface market and build to Lunar orbit, than build to high earth orbit [and Mars orbit or anywhere other then LEO], and then do LEO.
Mars doesn't follow these rules- it doesn't have a shortage of market, it's problem is having enough and it cheap enough for settlers to buy. One will basically **make** a Mars settlement if one has billions of tonnes of water and water is say is only 100 times to cost of water as water is on Earth. And it's possible that Mars water if using billion of tonnes per year, is about same cost as water on Earth- if you are merely pumping it from a fairly shallow well. But not going to happen if digging [or blasting] permafrost and processing it into water or turning briny water into fresh water.

Anyways, NASA would need a mars base to explore Mars to determine if and how Mars settlement could be viable. Or it's not strictly speaking only about launch cost from Earth to Mars.
Or with both Moon and Mars it not dependent on launch cost- certainly helps to have lower cost and if lunar water is minable and/or Mars is viable to settlement [and is settled] the launch cost would reduce in costs- or market tend to drive down costs.
« Last Edit: 05/29/2017 11:18 AM by gbaikie »

Tags: