Plan a Lunar Mission

[Ki11aWi11]

Moon, like Earth's moon. Not Mun.

There are also some significant problems with a Moon base, primarily water, and secondly power. The lunar night is half a month long, so solar panels and batteries probably won't cut it. You'll need a nuclear power source, ideally thorium as anything that needs water as a coolant won't be useful at all.

With the parameters you've given me, I'd launch large automated rovers that have heavy duty cables running to a thorium powerplant and some empty modules, the rovers are basically construction equipment that simply land and begin connecting modules together. They also cover the modules with dirt to shield them from solar wind when the moon is exposed. Once the base is largely complete and shielded I'd begin sending my astronauts out to settle inside the modules. The base would probably be dug into the side of a crater, with a launch site in the center of the crater and then all the communications equipment on the edge of the lip.

[Titan Space Agency]

Ok ten I will plot out my moon base.

Edited July 28, 2013 by Titan Space Agency
already ansered

[Titan Space Agency]

What if we use them only in space?

[NGTOne]

What if we use them only in space?

No, I mean not even a test model was ever built (again, with good reason) - Orion-style nuclear pulses were a paper project, and nothing else. At least they static-fired the NERVAs.

[metaphor]

There are also some significant problems with a Moon base, primarily water, and secondly power. The lunar night is half a month long, so solar panels and batteries probably won't cut it. You'll need a nuclear power source, ideally thorium as anything that needs water as a coolant won't be useful at all.

I was assuming the base to be near one of the poles, where there are deposits of water ice in permanently-shadowed areas of craters, and also peaks of eternal light which could be useful for solar power.

Actually now that I think of it, that would make the delta-v needed to land and return from the Moon larger since you need a plane-change maneuver, maybe by about 0.2 km/s. That makes a pretty big difference in the mass that can be carried down or up. The problem with a Moon base or having a reusable "Moon shuttle" is that it takes so much delta-v to go from LEO to LLO and back, a lot of designs are just impossible due to the tyranny of the rocket equation.

Edited July 28, 2013 by metaphor

[Fox62]

Actually now that I think of it, that would make the delta-v needed to land and return from the Moon larger since you need a plane-change maneuver, maybe by about 0.2 km/s. That makes a pretty big difference in the mass that can be carried down or up. The problem with a Moon base or having a reusable "Moon shuttle" is that it takes so much delta-v to go from LEO to LLO and back, a lot of designs are just impossible due to the tyranny of the rocket equation.

Hence why the Moonshuttle uses NERVA engines.

[metaphor]

Hence why the Moonshuttle uses NERVA engines.

It looks like your design has a 25.6 ton NERVA engine with 25 tons of cargo. Even with the 850s Isp of the nuclear engine, it would take 100 tons of fuel to go from LEO to LLO and back. Also I'm not seeing how people/cargo would go from lunar orbit to the Moon's surface in your plan.

[Fox62]

The personnel would use modified Altair landers that are, after personnel delivery, flown back up to the station remotely and refuelled. They have been modified so that they only use reusable and replaceable droptanks during descent, and an internal fueltank during ascent and rendevouz manuevers. The cargo would use conventional Altair Cargo Landers. Also, the Moonshuttle was assembled in orbit.

[metaphor]

So where does the fuel to refuel them come from? If you use chemical engines, anything you put into Moon orbit has to use at least 1.5 times more fuel when it's in Earth orbit. That's what I was talking about with the rocket equation being so harsh. Like if you want to put something that's 20 tons into Moon orbit with chemical engines, you need to lift 50 tons to Earth orbit. And that 20 tons in Moon orbit can only take 10-13 tons to the Moon's surface.

The Altair lander together with a command pod would take an entire Saturn V-size rocket to get to the Moon.

[Thaniel]

I remember reading a quick study that if the VASIMR or basic ion propulsion where used, and transfer from LEO to LLO could take weeks or months, then the propulsion stage could possibly be around half the weight of the cargo. But that would require either lots of solar panels or high efficiency nuclear engines in orbit. Nice for unmanned bulk freight though.

[Fox62]

So where does the fuel to refuel them come from? If you use chemical engines, anything you put into Moon orbit has to use at least 1.5 times more fuel when it's in Earth orbit. That's what I was talking about with the rocket equation being so harsh. Like if you want to put something that's 20 tons into Moon orbit with chemical engines, you need to lift 50 tons to Earth orbit. And that 20 tons in Moon orbit can only take 10-13 tons to the Moon's surface.

The Altair lander together with a command pod would take an entire Saturn V-size rocket to get to the Moon.

Who said that the landers came here on their own? And the fuel comes from Artemis Station, if you had actually been paying attention you would have guessed that! The landers were brought to the Moon by the Moonshuttle, which was assembled in orbit. Therefore bypassing the need to launch a massive spacecraft. Also, if that's the case, then how the hell would Constellation have worked? Your understanding of the rocket equation is invalid.

Edited July 29, 2013 by Fox62

[rpayne88]

Yes, NERVAs are fine, as long as they're of a reasonable size (i.e. roughly equivalent to the ones tested in the 60s, adjusted for technological advance - let's say a 20% decrease in mass over that period). Also, due to environmental and nuclear-safety regulations, you're not allowed to deorbit them into Earth's atmosphere, or fire them in it.

What if you deactivate them and de-orbit them in such a way as to allow them to land safely and be recovered?

[NGTOne]

What if you deactivate them and de-orbit them in such a way as to allow them to land safely and be recovered?

They're still radioactive, and you don't know exactly where they'll end up.

[Fox62]

What about de-orbiting them into a specified bit of ocean? or having a metric **** ton of parachutes on the NERVA.

[NGTOne]

What about de-orbiting them into a specified bit of ocean? or having a metric **** ton of parachutes on the NERVA.

The landing envelope for non-gliding deorbit isn't exactly small - most "capsule"-type spacecraft require (or at least they used to) a couple of days of search before they're recovered. If you're splashing the NERVAs, you have no idea how long you have until it sinks (and you've left an active radiation source at the bottom of the ocean). As for landing them on land, you can't run the risk that someone might find it and irradiate themselves - look up the Goiana accident.

[Fox62]

Okay, what about attaching an aeroshell that allows it to perform a Curiosity type re-entry?.

[NGTOne]

Okay, what about attaching an aeroshell that allows it to perform a Curiosity type re-entry?.

I think we've missed the bigger question - why would you WANT to deorbit a NERVA?

And there are alternatives to deorbit for debris disposal - you could send it up to a so-called "graveyard orbit" (a non-useful orbit where space junk is sent to float). That might even be easier, during most parts of a lunar mission, than deorbit.

[metaphor]

Who said that the landers came here on their own? And the fuel comes from Artemis Station, if you had actually been paying attention you would have guessed that! The landers were brought to the Moon by the Moonshuttle, which was assembled in orbit. Therefore bypassing the need to launch a massive spacecraft. Also, if that's the case, then how the hell would Constellation have worked? Your understanding of the rocket equation is invalid.

Where does the fuel in the Artemis Station come from?

Constellation at first would do Apollo-style moon landings, needing more than a Saturn V-sized rocket to get a four-person lander to the Moon and back. As for a lunar outpost, you can take more mass to the lunar surface if you're not planning on bringing it back. Even then, it would take two flights of an Ares V (with a capacity of 188 tons to LEO) to put a 35 ton module on the Moon's surface (that's about the size of a four-person habitat). For comparison, the Saturn V could only take 120 tons to LEO. That's partly why Constellation was cancelled from being too expensive, because you need a lot of rocket to land something on the Moon.

What Constellation was presumably going to do after setting up an outpost was to start ISRU (In-Situ Resource Utilization) to make fuel on the Moon. That would significantly decrease the mass needed to be lifted from Earth.

[metaphor]

I think we've missed the bigger question - why would you WANT to deorbit a NERVA?

And there are alternatives to deorbit for debris disposal - you could send it up to a so-called "graveyard orbit" (a non-useful orbit where space junk is sent to float). That might even be easier, during most parts of a lunar mission, than deorbit.

If you're on a Earth-Moon transit, you can send the NERVA on an escape trajectory using either a Moon or Earth slingshot depending on which way you're going. That's what they did with some of the used stages in the Apollo program.

[NGTOne]

If you're on a Earth-Moon transit, you can send the NERVA on an escape trajectory using either a Moon or Earth slingshot depending on which way you're going. That's what they did with some of the used stages in the Apollo program.

And now, 50 years later, they're mistaking them for asteroids

[nhnifong]

1. You are limited to present-day (and historical) launch vehicles and technologies. No VASIMRs or SABREs, no SSTO spaceplanes. Space Shuttles and Saturn Vs are fine, though. NERVA engines are OK, but you're not allowed to fire them in Earth's atmosphere, or deorbit them onto Earth (due to environmental and nuclear-safety regulations).

2. Your development, testing, and launch budget is near-unlimited, and certainly not the shoestring NASA has to put up with these days. However, you are limited to one launch every 50 days for a Saturn V-scale launch vehicle (due to limited launch and production facilities). Smaller vehicles can launch more frequently.

3. Your goal is to put a colony of no less than 100 people on the Moon by 2023. This colony should satisfy the following conditions:

i. As self-sustaining as possible

ii. Provides some entertainment facilities to prevent the colonists from taking a walk out the nearest airlock

iii. Provides some justification for its existence (scientific/economic/spaceport/whatever else you can think of)

4. In the event of a major decompression/radiation/whatever else emergency, the entire colony is capable of surviving for up to 3 weeks before rescue arrives (it can be assumed that they will all be evacuated at the end of the 3-week period).

So, have at it! I'm curious to see what kind of real mission the KSP community can come up with

Alright, to begin, I'm going to have a fleet of machines designed and built. None will exceed 20 metric tons individually. Each will have a standard load bearing docking mechanism at the top, and be delivered to LEO using a Delta 4 Heavy, then rendezvous with a standard lunar transfer stage delivered on a suitable American vehicle. The transfer stage will take it to lunar orbit. In lunar orbit, I will have a re-usable lander which refuels from the transfer stage. It will take the remaining fuel and the payload, land it at the work site, then launch itself back to orbit. This process will run once every 18 days until all modules have been landed at the work site, a crater near the southern hemisphere.

* a large 4-part landing platform to be assembled on top of the entrance to the main cave. one quad features an airlock and elevator.

* 10 electric lunar regolith tunneling machines with deployable conveyor belts for moving material

* 2 20 ton liquid salt battery banks.

* 1 sq. kilometer of unrollable solar panels and standoff pins for laying them over rocky terrain.

* 10 generic electric tractors with 2 industrial robotic arms each. Run on tank treads and recharge from stationary battery banks, strong enough to lift their own weight.

* Shovel, gripper, welder, blower, and cutter attachments for the robotic arms.

* 2 large flatbed trailers with cranes. (capable of moving any of the 20 machines that don't move themselves.

* 10 hopper trailers for moving regolith dust.

* 5 kilometers of combined power/data cabling and 200 generic router-couplers.

* 10 standard vehicle charging stations.

* 2 regolith processing facilities that electrolyze the regolith dust into hydrogen, oxygen, silicon, etc.

* 4 fluid storage tanks and 10 km of pipeline, gas and liquid pumps

* 100 assemblable pressurizable raw material and goods storage boxes.

* A machine that makes water and electricity from the hydrogen and oxygen.

* A machine that makes some kind of airtight insulating foam cement from regolith.

* A tool that the tractors use to spray that stuff all over the walls.

* 50 large fans for air cirulation

First, a tractor will be landed with built in deployable solar collectors. Driven by pilots on Earth, the tractor will be used to assemble the 4 landing pad components. further components will be landed on it and moved with the tractor. The solar panels will be laid out and connected to the battery banks. They will then connect a few vehicle charging stations and other key equipment to the power/data network. The tunneling machines will tunnel into the side of a hill and slant down until they are 100 meters below the surface, then fan out and build concentric rings divided into sectors. The regolith will be hauled out via hopper carts and dumped near the entrance. All the other machines will be carried into the tunnels and connected to power/data. The processing machines will begin producing gases and water and storing them in tanks. Insulating foam cement will be produced and used to seal the walls and build a rectangular frame at the entrance. A large airlock will be installed at the door along with piping and pumps for reclaiming atmosphere. At this point, the machines will begin filling the facility with gasses and heating it up to 20° C.

Dragon capsules will begin launching from Earth with 7 people each, and landing on the launchpad at the moon, once per week. In tandem with this, lights, clothing and bedding, drywall, furniture, nonperishable food, seeds, vegetables, fruits, mushrooms, and small machines will be delivered and the inside of the caves will be furnished and dedicated to various purposes by the inhabitants. Soil and essential nutrients will be shipped from Earth and used to begin farming vegetables to supplement periodic supply ships. The purpose of the outpost will be to study lunar agriculture. They will attempt to design a stable self-contained ecosystem which can produce a varied diet for the inhabitants while requiring minimal nutrients and water from Earth. All inhabitants are entitled to a one-way return to Earth once each year, during the same month they arrived, as long as there are at least 107 able-bodied people present to operate the facility. Upon announcing their return, a sufficient quantity of fuel will be sent to the moon (or produced on site if possible) and used to refill one of the dragon capsules on-site. All inhabitants wishing to return home will board it and it will fly back to earth and soft land at the launch center.

Estimated up front cost: $100 Trillion

Estimated upkeep cost: $5 Trillion per year

Edited July 30, 2013 by nhnifong

[DerekL1963]

The landing envelope for non-gliding deorbit isn't exactly small - most "capsule"-type spacecraft require (or at least they used to) a couple of days of search before they're recovered.

Only if by "used to" you mean "for a really short period back in the 1950's" or "later, under unusual circumstances". At any rate, nowadays there's no particular reason a capsule can't have a CEP < 1 mile or so. Anything under five or ten miles works for an open ocean landing.

If you're splashing the NERVAs, you have no idea how long you have until it sinks (and you've left an active radiation source at the bottom of the ocean).

Just like we had no idea how long it was until the Apollo capsules sank... oh, wait. We have these people called engineers nowadays who can design stuff and run tests so we *do* know.

As for landing them on land, you can't run the risk that someone might find it and irradiate themselves - look up the Goiana accident.

Which is why they wouldn't be targeted to land where some random person can wander across them. Plenty of wide open spaces with controlled access in the US alone. Not to mention the ability to track them as they come down, and deploy support personnel via helicopter. (As was done with Genesis.)

Seriously, where do you get this stuff?

[NGTOne]

Only if by "used to" you mean "for a really short period back in the 1950's" or "later, under unusual circumstances". At any rate, nowadays there's no particular reason a capsule can't have a CEP < 1 mile or so. Anything under five or ten miles works for an open ocean landing.

Just like we had no idea how long it was until the Apollo capsules sank... oh, wait. We have these people called engineers nowadays who can design stuff and run tests so we *do* know.

Which is why they wouldn't be targeted to land where some random person can wander across them. Plenty of wide open spaces with controlled access in the US alone. Not to mention the ability to track them as they come down, and deploy support personnel via helicopter. (As was done with Genesis.)

Seriously, where do you get this stuff?

Fair arguments on all counts. However, I'm still of the belief that the world's governments wouldn't appreciate radioactive space debris coming crashing down (on purpose or by accident).

[Fox62]

Then what about the government launching the stupid thing bringing it back on their own turf?

[Thaniel]

Why bring it back down the gravitywell again at all? Make it modular, leave it in orbit, and land using conventional systems. That way the engine can be used for other trips later on.

Edited July 30, 2013 by Thaniel