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As for Elderflower solutions, bringing any amount of fuel to Mars orbit or even worse as you need to land it - to surface, scales costs of the missions in very bad way. The choices are no return or make fuel on site for the landed cargo to make the way home. This is why the return trips should be reduced to minimum.
Hello.
As you may know I want to answer what it is that stops mankind from going to Mars. The only solution that currently may bring us to another planet is Spacex's BFR, yet their design is being disputed as inefficient for dead cargo transportation. The other option that can compete in terms of efficiency with direct payload transport to Mars is disconnecting one-way one-shot lander with cargo at Mars orbit as this solution makes the landed part of vessel lighter. This way the transporting spacecraft may also be lighter (no need to sustain heavy loads on ascent), can be designed with high Isp engines and does not need a heavy heat shield.
I cannot find reason to discard this proposal so I created a page where such design will be evaluated: spacetechs.ovh.
Currently the problem with this design is the dv needed to park in LMO. This may be solved by aerobraking maneuver, so based on data from internet i written a simple calculator that simulates this procedure. Simulation was calibrated with data on mars reconnaissance orbiter and shows good results.
The periphrasis altitude that allows to park heavy (250t+ mass) ship in orbit in 5+ months seems to be somewhere between 65km to 70km (30 km lower than in MRO mission). Now, the next step is designing proper heat protection and here is the subject.
Does anyone know a proper software or person that can calculate the temperature on the spacecraft surface given model (shape), velocity and the Mars(!) atmosphere density?
Hello.
I am creating this topic in hope of finding an open source space projects. By "projects" i mean a real attempts at creating stuff in space with calculations and drawings, not just campaigns and initiatives to improve support for space industry.
I myself started to work on such project (as a hobby), did some initial calculation and idea of unmanned cargo transport vessel (space tug) seems quite feasible. Since this is probably the "easiest" (if there exists the "easy" in rocket science) possible construction that can be designed to fly in space i think that there might be some ongoing works that could use support or halted attempts that can pushed a bit forward. Any idea where things like that can be found?
Damn.. this is slowly evolving into theoretical discussion without the numbers and facts, the only thing that i would like to avoid.
The BFR will most likely be useless for any other mission than trip from Earth surface to Mars surface and back. The fuel used in design and versatile engines capable of lifting and space travel are not efficient for space mission.
The BFRs data: dry weight: 85t, payload: 150t, fuel: 1100t. This gives the delta-v equal to 6.51 km/s.
The simple spacecraft designed with 4xRL-10B-2 (1t) engines + SLWT tank (26.5t for 600t of fuel) + constr (added to compare) + payload 150t needs 755t of fuel to get the same delta-v. That is 345t less mass to LEO, assuming lifting with current best solution (Falcon Heavy $1411/kg) we have $486,795,000. Furthermore the construction weight added to compare the solutions will be much smaller, since no landing gear is required (or the landing gear may be attached to "droped cargo" so constructions becomes payload in "drop" mission). Again, this does not work for humans and delicate cargo needs proper landing gear, but everything else (food, construction materials, lander, space station)? yes, also may be used in missions to other objects, not only mars, plus gets more efficient with better lifting to LEO solutions (perfect fit for LEO reusable Spacex vessels).
Louis,
It is just my bad english understanding. I assumed that Mars surface is "near" mars (like mars + moons) and i think that you too agree that at least one of those places needs fuel production site.
The Deimos production plant + mars fuel production (in next step) in my opinion is better since you do not need to lift fuel from Mars to go back to Earth (you can refuel again in orbit). I did not look at fuel production tech on mars yet so I am very worried about the mars refinery efficiency - can it product enough fuel in time?
Most of the crafts will carry one way cargo, not humans, so they actually do not need to land, rather just "drop" the cargo, refuel in orbit and go back. I am working on concept of such craft like that right now actually, as the figures are really promising.
The greatest improvement compared to BFR is the possibility to use better engines, since atmospheric starts are not required (Isp-v = 4.53 vs 3.75 in BFR). This difference can compensate for taking the fuel for empty ship return, but that is no the best thing i like in that design.
Spacecraft like that would work with, and not against the BFR. Great reduction in LEO costs would also reduce ITV refuel needs so this always will be the least expensive option for "bulk" cargo, but only BFR can land with humans.
May I ask for the contact to GW to double check my calculations?
Sorry. I did not state clearly that I am suggesting unmanned prepare mission, that should confirm the presence of the water and next expand into automatic production plant on Deimos.
The goal is self sustaining colony on mars surface, not just landing and returning like in the spacex mission. The question to be more precise is: what infrastructure should be placed before mars manned mission and in what order (actually the single next thing, not the all pices). Regarding my research I found some data and did some math, that needs to be checked (the option with "truck" spacecraft that would go back and forth between mars and earht orbits, variant without resupply on mars). Can I post it here to get verification?
LEO→LMO: 4.697 km/s
LMO→LEO: 2.75 km/s
Engine Isp: 4.53km/s
Trip to mars
Fuel 250.00t
Ship 12.39t
Cargo: 100.00t
Return needs: 23.39t
Total (no fuel): 135.77t
Total: 385.77t
ln(m1/m2) 1.04
dv needed 4.70km/s
dv provided 4.73k m/s
Retrun To Earth
Fuel 11.00t
Ship 12.39t
Cargo 0.00t
Total (no fuel)12.39t
Total 23.39t
ln(m1/m2) 0.64
dv needed 2.75km/s
dv provided 2.88km/s
Hello.
I am doing some research on mars missions and i found this great forum. There is a lot of valuable resources here but i would like to get some summary on the subject, and so.. If you were to decide today (using available technologies, not inventing new ones!) on the next step towards mars colony, what would it be?
The data i gathered until now suggest this:
Sending probe with mining and research equipment to Deimos to check for water.
Why? Most agree that without fuel supply near Mars there is no way to feasible conduct missions. The means of water extraction on Mars are being developed and that water can be processed into fuel but to lift it from Mars one would need to create a lot of it. Possible source on some smaller body that can resupply the spacecraft in orbit would be (in my present opinion) best option for moving object from Mars orbit to LEO.
What do you think?