Talk:Manned resupply mission

Open issues

• What is the financial effort estimation of such a mission?

• Trying to keep the financial effort near that of a luanr mission.

• What is the advantage of such a mission over a research contract between terrestrial scientists and Martian colonists,

where only the scientific gauge is physically shipped to Mars, and the colonists take the measurements?

• This mission gives the colonists the chance to see new faces, meet new people, socialize, interact, etc. It also gives the chance for people to join or leave the colony.

• How does the lander work?

• I would think about the DC-X prototype vehicle.

• What parts of the lander are reusable?

The whole lander.

• How much fuel is required to launch/land the lander from/to the colony?

To land the lander, 15% of the landing weight has to be propellant. Less fuel would be needed to launch the lander from Mars then would be needed to launch a similar sized vehicle from Earth.

• How many persons are required to maintain the lander after the operation? How long would that take?

The scientist are there until the next launch window. There are two years to refit the lander. The DC-X needed a very small workforce to keep it running.

• How much energy is required for the life support systems on the transfer craft? It must be able to counteract the *metabolism of the crew.

• We have done this before, on Mir and the ISS. However, Mir and the ISS did not recycle CO2, water etc. We will need a fully self sufficient life support system. Because it recycles the waste, less mass will be required to replenish the loss.

• What is the mass of the transfer craft, including radiation protection and energy generation modules?

Trying to keep the mass of the hab less then a fully fueled LSAM. The habitat is inflatable, which means less mass for more volume (Am I correct?). Add to that the tether and radiation shielding. The hab wont protect against solar flares, the travelers would have to retreat to a storm shelter or the CEV, if it has enough shielding. The power generation systems are much smaller then those on the ISS because only the hab needs power, there is not an array of scientific instruments on board. T.Neo 08:21, 20 August 2008 (UTC)

Hi T.Neo, I admire your optimism. How far would we go without our dreams:-) Hopefully, all our dreams about manned missions to Mars come true one day. But to reach that goal we need clear figures. What a lunar mission would cost today is quite unclear. As a matter of fact the average cost to launch a Space Shuttle is about $450 million per mission ([1]). Now we can easily calculate the estimated effort of manpower with an average salary of $1000 per month: 450000 persons have to work one month for it, or 18750 persons have to work for two years to do everything that is needed to maintain and refuel the space shuttle. On Mars it will hardly be much cheaper. So, a Martian colony with 18750 colonists is entirely occupied to work for a periodic "manned resupply mission", which is taking place every two years. Well, it seems to be far beyond the abilities of a small colony. -- Rfc 20:17, 21 August 2008 (UTC)

One of the drawbacks with the shuttle is the intensive maintainance. The lander would not need such maintainance. See here:

Another focus of the DC-X project was minimized maintenance and ground support. To this end, the craft was highly automated and required only three people to man its control center (two for flight operations and one for ground support). In some ways the DC-X project was less about technology research than operations.

The lander will probably be larger then the DC-X, but smaller then a Earth-based launcher with the same payload capacity. How many colonists in an early colony? How many people does it take to, say, maintain a Boeing 737 aircraft?

Maintanance is not a show stopper. If it is totally impossible to maintain the lander on Mars, an expendable one could be brought to Mars for every mission by something like a direct cargo flight. The mission might cost more for Earth, but much, much less for Mars. T.Neo 07:14, 22 August 2008 (UTC)

The lander would definitely need maintenance and fuel. "minimized maintenance" does not mean zero maintenance. I do not know the exact figures, but optimistically, I would expect half of the Space Shuttle's maintenance effort. Even if it is a tenth (which is too optimistic), this still occupies 1875 persons entirely. On the other hand the settlers have to fight a daily battle just to keep themselves alive, due to the scarcity of energy. -- Rfc 17:33, 22 August 2008 (UTC)

As I said before, if it is prohibitive to maintain the lander on Mars, then it can be placed in Mars orbit by an unmanned rocket launched from Earth. The lander is expendable. I was being stupid, only thinking about the monetary cost to Earth, and thinking of the martian cost in resources as an aside. It might be cheaper in the whole scheme of things, to have three launches instead of one. My previous queastion: how many people does it take to maintain a medium sized airliner? We shouldn't be looking at the shuttle as a comparison to the Lander. A expendable lander would be much easier to make in the first place. Maybe all mission components could be mass produced, like car parts.

As for the scaricity of energy, one of the advantages of a semi-autonomous colony is that a nuclear reactor might be a possibility. The base would also be maximised to be energy efficient, and thus have plenty of energy from the reactor available. Solar concentrators and wind turbines could be packed up in a "safe" configuration, preventing damage from the sun, sand and corrosive environment. A Semi-autonomous base will be full of failsafes. T.Neo 09:43, 23 August 2008 (UTC)

Interesting concept. Sounds like a really big enterprise. -- Rfc 20:22, 23 August 2008 (UTC)

What is a really big enterprise, making expendable landers? Having a nuclear reactor at the colony? Mass producing mission archetecture? Having a settlement full of failsafes?

Other possibilities:

• Make the lander the habitat during the cruise phase. However, fuel will either be shipped from Earth to a depot in Mars orbit or made on Mars itself and shipped up in the lander for the departure phase.
• Ship the lander to Mars beforehand, fuel it using automated systems at the base, and use the transfer habitat as a one-way lander to the surface, and then use the previously shipped lander as an Earth return vehicle to return home (That is mars direct.)

T.Neo 07:13, 25 August 2008 (UTC)

Big is the whole mission. Okay, you think in big scales, and this is possibly the only way of building an autonomous colony. My thinking is rather small scales, with respect to the small budget of NASA, ESA, etc. Maybe private equity is the key to do the big scale approach.

And a nuclear reactor is an extraordinary big thing. What size do you have in mind? There is probably a minimum size for ecological viability.

You have mentioned a whole bunch of concepts. How about filling a special article with a systematic overview of all the mission concepts, making them easy to compare? -- Rfc 18:51, 25 August 2008 (UTC)

Small nuclear reactors exist, they are used on nuclear submarines. Plus, if I am correct, the Soviets used nuclear reactors in some spy satillites. The reactor would be minaturized, and would be encased in heavy shielding (Graphite, Boron, etc.). This shielding would act as a heat shield if in any disater with the launch vehicle the reactor dropped into the sea it would not contaminate the environment. On arrival to Mars, the reactor will be placed in an undergroud bunker, connected to other systems and activated. One little reactor isn't so bad, considering some ideas for Mars transit ships have 3 (!), and the aldrin cycler concept also includes a reactor. These lightweight reactors will be vital if we ever want to explore or settle the outer solar system (The other day I thought of an autonomous colony one the moons of Saturn. I felt sorry for the imaginary colonists, realised how in comparison Mars is a piece of cake.)

Multinational cooperation will probably be needed, and I see the private sector playing a big role as well. Something like a mission archtecture article would be a good idea. T.Neo 06:19, 26 August 2008 (UTC)