Proposed Viable Mars Colony

[MentalAvenger]

IMO, the only practical way to send humans to Mars is with a large initial group, possibly 200 individuals, one way. Sending 7-8 astronauts on a round trip is pointless. It dramatically increases the energy requirements, limits the time on surface, and doesn’t really accomplish anything.

Start by sending orbiters capable of very high resolution imaging of the surface.

Send several large rovers to Mars to find the best place to start a colony. I suggest SUV sized rovers, capable of high speed travel, 10 meter deep core drilling, and onboard sample processing. I call these rovers Big AL.

Using information from the orbiters, land the rovers in the most promising areas. Once the rovers have found the best site, send robotic supply ships via the economy route and land them at that site. The robotic supply vessel hulls can be pre-fitted with electrical wiring, plumbing, and other fixtures so they can be used as habitats when emptied. Enough supply vessels should be sent to ensure sufficient habitats and supplies for the proposed colony size, and for at least 5 years.

Then send in the first 200 colonists. All these missions will be one way, maximizing the amount of cargo and people they can carry. The 200 colonists will cover every possible area of expertise, and all will be cross trained in at least two other areas, with additional general training.

The colony can be built by moving the cargo vessel/habitats into nearby ravines and interconnecting them. If no ravines are available, trenches can be dug into the surface. Supplies can temporarily be stored in tents on the surface. Included regolith moving machines or Big Al can be used to cover the habitats with sufficient regolith to shield inhabitants from radiation. Another option is to send a nuclear tunnel boring machine and bore into rocky hillsides or the walls of natural canyons. We might even get lucky and find networks of natural caves.

[Ara Pacis]

Sounds about right by my estimation. I've always said we should send an initial mission of a few hundred: certainly no less than 20-50.

I don't think they'll need a nuclear tunnel borer right away, but maybe by the second or third trip, they'll better know their needs and where and how to establish a city-sized colony. But if they have the surplus mass allowance, maybe they should.

[Glom]

10 meter deep core drilling? That's one hell of a bit to load onto an SUV!

[MentalAvenger]

Mars is much smaller than Earth, so meters there are shorter.

[MentalAvenger]

Drill stems usually come in sections. Use as many as required. I suggested 10 meters because, initially, it would be impractical to go deeper to mine materials.

[Glom]

You're talking about depth? I thought you were talking about diameter.

10m is a standard length for drill pipe (well 30ft actually). So if you intend to go down 10m, you will probably be drilled with your kelly alone.

[MentalAvenger]

You're talking about depth? I thought you were talking about diameter.

I don’t think so, Tim. Typical core samples on Earth might be 4-6 inches in diameter. For testing down to 10 meters on Mars, core samples of perhaps 1-2 inches might be sufficient, since the samples would be limited to chemical and composition analysis onboard. It could be carried as three 3.3 meter sections outside Big Al.

The initial Big Al rover survey would be used to search for sites relatively rich in resources the colony might need, such as metals or subsurface water or ice.

[Ara Pacis]

But the pipe's not large enough for Bruce Willis to fit a nuke through.

[MikeMcc]

Pretty much what Kim Stanley Robinson laid out (though he started with 100 colonists). I doubt you could do this mission in the present political climate (NASAs hyper safety culture) without having some escape means, so you might need to pre-position return vehicles even if the trip is intended as one way. They can be returned with samples or returnees anyway (once the populations grown to produce a reasonable number of them).

[swampyankee]

But the pipe's not large enough for Bruce Willis to fit a nuke through.

A pipe with a 155mm ID would fit a nuke. Of course, Bruce could just order the anti-matter bomblets.

[MentalAvenger]

Pretty much what Kim Stanley Robinson laid out (though he started with 100 colonists). I doubt you could do this mission in the present political climate (NASAs hyper safety culture) without having some escape means, so you might need to pre-position return vehicles even if the trip is intended as one way. They can be returned with samples or returnees anyway (once the populations grown to produce a reasonable number of them).

Return trips would be impractical and extremely expensive. Since all supplies would initially have to come from Earth or the Moon, the fuel for a round trip would be more than three times the fuel used in a one way mission. Using conventional propulsion for the entire trip, that would increase to four times as much fuel. If you include liftoff from Mars, that could be 5-6 times as much fuel.

A Mars colony would not be a resort or a tourist destination. There would be no reason to return samples to Earth. All analysis could be done on Mars.

[MikeMcc]

I wasn't saying it was sensible, only politically expedient (probably as a reason to kill off the idea quickly!)

[kamaz]

Return trips would be impractical and extremely expensive.

Not true in general:

[Mars Direct] sums up to 64.28 tons. Going one way amount to doing away with return vehicle and consumables for the return trip, bringing the total mass budget to 49.34 tons. That's only 23% reduction in weight. Next, such mission profile requires 3.6 tons of consumables to be send every opportunity (2 years) so the crew can survive another 2 years on the surface. So the mass budget breaks even after 4 supply missions, i.e. 8 years. And that does not include spare parts or new equipment, which will need to be replaced as well.

The only situation one-way mission profile would make sense is when sending large groups of people (hundreds) together with hydroponic greenhouses, machine shops etc. But this is off the table for a long time to come.

Since all supplies would initially have to come from Earth or the Moon, the fuel for a round trip would be more than three times the fuel used in a one way mission. Using conventional propulsion for the entire trip, that would increase to four times as much fuel. If you include liftoff from Mars, that could be 5-6 times as much fuel.

That problem has been solved by Zubrin 20 years ago by producing propellant from Martian atmosphere. Plus, there is hope that Phobos may contain ice, which would allow refueling there.

In short, you really want reusable Mars<->Earth shuttles and in situ propellant to keep costs down. And once you have these, you suddenly have seats on return trips.

And having a return option does not preclude staying on Mars.

[MentalAvenger]

Not true in general:

I disagree. The facts show otherwise.

That problem has been solved by Zubrin 20 years ago by producing propellant from Martian atmosphere. Plus, there is hope that Phobos may contain ice, which would allow refueling there.

There is no practical way to be set up to produce propellant before the colony is set up. Also, that propellant would then have to be lifted into orbit. It would be even longer, if ever, before there would be any fuel production on Phobos.

In short, you really want reusable Mars<->Earth shuttles and in situ propellant to keep costs down. And once you have these, you suddenly have seats on return trips.

You quoted Mars Direct, which is a radically different concept than the proposal I suggested here. The robotic supply ships would all be used, intact, as habitats. It would be foolish to send all that hardware back where it came from when it would be so useful on Mars. We already deliberately burned up all the STS external tanks, which could have been left in orbit to build space stations or supply depots. Should we continue such wasted effort?

[Ara Pacis]

There is no practical way to be set up to produce propellant before the colony is set up. Also, that propellant would then have to be lifted into orbit. It would be even longer, if ever, before there would be any fuel production on Phobos.

Sure there is, send the fuel manufacturing one or two oppositions ahead of the first colonization wave. It may not be part of your plan, but I suppose we're not going to be starting ASAP, so we have some time. There's no really good reason not to send them ahead and if anything, it will test out high-mass landing strategies.

You quoted Mars Direct, which is a radically different concept than the proposal I suggested here. The robotic supply ships would all be used, intact, as habitats. It would be foolish to send all that hardware back where it came from when it would be so useful on Mars. We already deliberately burned up all the STS external tanks, which could have been left in orbit to build space stations or supply depots. Should we continue such wasted effort?

If the STS ETs burned up, then perhaps they weren't in orbit. IIRC, it's still too low and slow and not just circularization issues, but I could be wrong. Anyways, why use material that is probably better as a spacecraft. I think it would be easier to bring along lightweight panels, fabrics and I-beams to use as structural material as cargo than try to create an orbital chop-shop.

[Glom]

If the STS ETs burned up, then perhaps they weren't in orbit. IIRC, it's still too low and slow and not just circularization issues, but I could be wrong. Anyways, why use material that is probably better as a spacecraft. I think it would be easier to bring along lightweight panels, fabrics and I-beams to use as structural material as cargo than try to create an orbital chop-shop.

An empty ET doesn't weigh a lot. Circularisation with it still attached shouldn't be an issue. The ET is deliberately burnt up to get rid of it so it doesn't continue hurtling around the planet for the next couple of years.

[MentalAvenger]

The STS External Tanks weigh about 58,000 lbs. At 153 ft long and 27 ft in diameter, they have an internal volume of about 80,000 cubic feet. The combined volume of the LOX tank and the LH2 tank is about 72,400 cubic feet. Assuming ET from 120 shuttle missions, that would be 9,600,000 cubic feet of enclosed space, equivalent to a habitat about 27 feet in diameter and 16,800 feet, or 3 miles long.

Imagine the space station they could have built with that for a tiny fraction of the cost.

[MentalAvenger]

If the STS ETs burned up, then perhaps they weren't in orbit. IIRC, it's still too low and slow and not just circularization issues, but I could be wrong. Anyways, why use material that is probably better as a spacecraft. I think it would be easier to bring along lightweight panels, fabrics and I-beams to use as structural material as cargo than try to create an orbital chop-shop.

STS mission profiles include a dip maneuver which sends the ET back down into the atmosphere.

[IsaacKuo]

An empty ET doesn't weigh a lot. Circularisation with it still attached shouldn't be an issue. The ET is deliberately burnt up to get rid of it so it doesn't continue hurtling around the planet for the next couple of years.

I'm a big lover of ET recycling concepts, but The Jim pointed out a serious problem with them--the ET is covered in foam which popcorns off. Left in orbit, an ET would turn into a major space junk generator.

[Glom]

STS mission profiles include a dip maneuver which sends the ET back down into the atmosphere.

What dip maneuver are you referring to? On MECO, without further intervention, the spacecraft, orbiter and ET, will reenter after the best part of an orbit. I'm not aware the spacecraft actually lowers its orbit with the OMS to put the ET on a reentry trajectory.

[MentalAvenger]

What dip maneuver are you referring to? On MECO, without further intervention, the spacecraft, orbiter and ET, will reenter after the best part of an orbit. I'm not aware the spacecraft actually lowers its orbit with the OMS to put the ET on a reentry trajectory.

The STS does not lower its orbit. It dips the orbiter nose downward, using the RCS engines to hold that attitude while the ET is ejected. Then the RCS reorient the orbiter for insertion into orbit. I don’t have a link to the NASA article where it was referred to as a “dip” maneuver.
”There are 38 primary Reaction Control System (RCS) engines and six vernier RCS engines located on the orbiter. The first use of selected primary reaction control system engines occurs at orbiter/external tank separation. The selected primary reaction control system engines are used in the separation sequence to provide an attitude hold for separation. Then they move the orbiter away from the external tank to ensure orbiter clearance from the arc of the rotating external tank. Finally, they return to an attitude hold prior to the initiation of the firing of the Orbital Maneuvering System (OMS) engines to place the orbiter into orbit.”
http://spaceflight.nasa.gov/shuttle/...uirements.html

[MentalAvenger]

I'm a big lover of ET recycling concepts, but The Jim pointed out a serious problem with them--the ET is covered in foam which popcorns off. Left in orbit, an ET would turn into a major space junk generator.

”There is concern that the Spray-On-Foam Insulation (SOFI) could erode in orbit and cause annoying and potentially dangerous debris (Fitch, 1997). Tom Abbott suggests his solution. “After the ET reaches orbit, it can be held in a 170 mile high orbit while the SOFI is scrapped off. One study predicts it would take less than a week to strip the SOFI, and debris would deorbit in from hours to a couple of days, depending on the size of the piece. Another is to leave the ET in a 160 mile orbit for about a month and all the SOFI would oxidize off of it” (Fitch, 1997, p. 4).”
http://aeromaster.tripod.com/paper1.htm#Problems

[Ara Pacis]

The STS External Tanks weigh about 58,000 lbs. At 153 ft long and 27 ft in diameter, they have an internal volume of about 80,000 cubic feet. The combined volume of the LOX tank and the LH2 tank is about 72,400 cubic feet. Assuming ET from 120 shuttle missions, that would be 9,600,000 cubic feet of enclosed space, equivalent to a habitat about 27 feet in diameter and 16,800 feet, or 3 miles long.

Imagine the space station they could have built with that for a tiny fraction of the cost.

I'm not against the idea, I just thought there was a prohibitive delta-v penalty involved.

I'm a big lover of ET recycling concepts, but The Jim pointed out a serious problem with them--the ET is covered in foam which popcorns off. Left in orbit, an ET would turn into a major space junk generator.

Would that happen with a painted ET? Couldn't it be wrapped so that the foam doesn't come off or escape?

[IsaacKuo]

Would that happen with a painted ET? Couldn't it be wrapped so that the foam doesn't come off or escape?

The paint had no significant effect on popcorning. Wrapping could be done, but it would have to somehow be done after launch, in orbit. If you tried to wrap it before launch, this would involve deal-killing problems with icing.

[MentalAvenger]

I'm not against the idea, I just thought there was a prohibitive delta-v penalty involved.

That would depend upon where you want the ETs to end up. For instance, if you used only ETs which were in the same orbital plane, you wouldn’t have to expend energy changing orbital plane. That would save a lot. It seems wasteful to throw away 58,000 lbs of good hardware that is already traveling at very near orbital velocity. Of course it would require an orbital tug to nudge them into place. But when it wasn’t towing ETs, it could be used to clean up some of the space junk in the orbital path.

[Ara Pacis]

That would depend upon where you want the ETs to end up. For instance, if you used only ETs which were in the same orbital plane, you wouldn’t have to expend energy changing orbital plane. That would save a lot. It seems wasteful to throw away 58,000 lbs of good hardware that is already traveling at very near orbital velocity. Of course it would require an orbital tug to nudge them into place. But when it wasn’t towing ETs, it could be used to clean up some of the space junk in the orbital path.

That seems like an anachronism. If we can have orbital tugs at hand, then why bother with converting fuel tanks. Besides, the shuttle is retiring and we may not use a shuttle derived launcher, so the point may be moot.

[Commodore]

Whats the biggest thing we can land on Mars with a pair of Falcon 9h launches, assuming one is all payload, and the other is a chemical propulsion/aerobrake/decent?

What if we add a 3rd, a dedicated EDS, that is included as payload once spent?

[MaDeR]

I am sorry, but for me, talking about Mars colony, when we cannot even put boots on Moon again, is just sadly hilarious. Anyone heard about "learn to walk before running"? Manned flight to Mars is suicidal with current tech. Case in point: often breaking machinery on ISS. Other argument: Moon is generally easier than Mars by orders of magnitude for anything that we would want to do with it involving manned spaceflight. Fact that Moon have different challenges than Mars does not change this.

So, in summary: no, just... no. Forget it. Focus on return on Moon. Otherwise, we will never fly anywhere.

[samkent]

You seem to have thought of most everything, except one.

How would my Ipad connect to the web?? I'm not going to Mars with out Facebook and Twitter!! Just how Hicksville do expect us to be?

[ravenhill]

IMO, the only practical way to send humans to Mars is with a large initial group, possibly 200 individuals, one way. Sending 7-8 astronauts on a round trip is pointless. It dramatically increases the energy requirements, limits the time on surface, and doesn’t really accomplish anything.

Start by sending orbiters capable of very high resolution imaging of the surface.

Send several large rovers to Mars to find the best place to start a colony. I suggest SUV sized rovers, capable of high speed travel, 10 meter deep core drilling, and onboard sample processing. I call these rovers Big AL.

Using information from the orbiters, land the rovers in the most promising areas. Once the rovers have found the best site, send robotic supply ships via the economy route and land them at that site. The robotic supply vessel hulls can be pre-fitted with electrical wiring, plumbing, and other fixtures so they can be used as habitats when emptied. Enough supply vessels should be sent to ensure sufficient habitats and supplies for the proposed colony size, and for at least 5 years.

Then send in the first 200 colonists. All these missions will be one way, maximizing the amount of cargo and people they can carry. The 200 colonists will cover every possible area of expertise, and all will be cross trained in at least two other areas, with additional general training.

The colony can be built by moving the cargo vessel/habitats into nearby ravines and interconnecting them. If no ravines are available, trenches can be dug into the surface. Supplies can temporarily be stored in tents on the surface. Included regolith moving machines or Big Al can be used to cover the habitats with sufficient regolith to shield inhabitants from radiation. Another option is to send a nuclear tunnel boring machine and bore into rocky hillsides or the walls of natural canyons. We might even get lucky and find networks of natural caves.

Google 'Mars holes'. First step for me would be to put a probe in one of those.