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I would argue that there could be a need for the origonal Shuttle-C and a STS derived HLLV. Shuttle-C would be excellent for more cheeply placing cargo in LEO, but its limited capacity (91t vs 209t) and nerrow diameter of the cargo pod would make a HLLV capible of using the same launch facilities a useful asset.
I just courious, what makes the Magnum incompatible with current launch facilities? It has a ET based core and shuttle boosters just like Ares. Is it the placement of the engines on the core?
Looking back at the designs proposed in NASA's DRM 1.0, one may fit you need and be less complicated. I like the option which uses a central booster based of a STS tank with three SSME's and seven strap on boosters with one RD-170 engine each. The upper stage would use one SSME. The design would lift 209 tonnes to a 220 n.mi. circular orbit. Replace the SSME's with RS-68's and the liquid boosters could be replaced with SRB if wished, although the liquid boosters would have their advantages. This will be more than enough to support a manned presence in Space and would use a mininum of new materials.
I still see the PRC as a major threat to regional peace. The political and economic situation seems to be changing. Over the past few decades China's economy has grown increasingly capitilistic and the Communist parties hold over the minds of its people is also weakening. I don't see the PRC disolving like the USSR, but the Communist party's days will likely be numbered in the next 50 years.
The PRC still has a long way to go to catch up to the US and Russia in space. I'm just hoping they light a fire under Congress, so we can get some real support for our space program.
Other then advocacy groups, I am not sure any are directly working to send people to Mars at the moment (not to say they are not working towards it technilogicaly). The ESA has stated that the plan to go to Mars in the long term, and the PRC has also stated that they intend to go as well. I don't know about the Russians, Energia has a plan, but development funds for the technology have been cut for budgetary reasons. NASA has stated several times that going to Mars should be an international effort, but no orginizing has happened to date.
Some of the probelm with musculer atrophy is caused by the fact that in 0g there are muscles that are simply not used at all, even in exercise machines. .38g would use these muscles to support the body, if only to a lesser extent.
More research definitly has to be done on the long tern effects of low gravity on mammals. Why not hang a spinning container off the ISS to test the effects on mice for a year or so. It could always be de-spun periodicly to be cleaned and reloaded with food.
The military is working hard to develope better tasting storible food. By the time we go to Mars, foul tasting MREs (Meals Rejected by Ethiopians as they have been called by some of my military friends) should be a thing of the past. I heard that the secret was to liberaly apply Mrs. Dash to the MRE to improve its taste.
I don't think the PRC could make it to Mars before the Russians or US if they tried. If they made a serious push, either NASA the ESA or both together would probly mount a crash program to get there first. China still has no manned space experience, no experience with HLV's, interplanetary probes, and very little experience in space in general. I would hate for them to go there first, have an accident, kill the crew, and discourage others from going.
If the Commies were there, I would sure bring some way for the crew to defend themselves to Mars, you could never be sure they wouldn't try something if it hit the fan. "Our reactor failed, we're taking yours"
The threat is not that they would use a missle against us to threaten us away, the People's Republic China has already threatened to detroy our cities and we still support the Republic of China. It would be suicide to strike at us. The only argument I think is valid is that some general makes a launch on their own accord.
If we are really worried about a threat, we could hit their missile bases first, a task we are more than capible of.
Mankind is capible of accomplishing nearly anything if we try. We could have gone to Mars with 60's technology. It wouldn't have been easy, but we could have done it. All we need is the will and the means, and that means money for the moment.
If the North goes nuclear, what makes you think that the South won't as well? They could easily develope the capibility in a short time. The balance of power never shifted. The North can't blackmail the South witha nuke because the South has nuclear allies as well, with much bigger arsonals. The existance of GBMI will not deter anyone from attacking.
Sorry, I usually forget about ion thrusters, they're such low thrust. I was thinking along the lines of a MPD. Yes, with lower power requirement engines like hall or ion thrusters, an RTG can provide the power.
What is the mass of all the batteries you would need for nightime/ emergency use? A dust storm could blot out your pannels for days, requiring considerable storage. Batteries are not light. The advantage of the reactor tis that it will work day and night, clear or covered. And it doesn't have the vulnerability of a thin plastic cylinder.
RTG's can only power electrical systems, they lack the energy to power a decent propulsion system. For that you need a reactor, the next logical step. They use nuclear fuel far more effiecently. I know some of the modern fuels, such as flip fuel, in research reactors can last 50-70 years, a thermal power system using such fuel could power a electric engine for decades. It is not as good for producing power as conventional fuel, but is still better then decay.
I would like to see the return of the old style "charter companies" which exploited so much of the world's resouces in the 16th-19th centuries. Driven by profit, they could efficently utilize resouces in the belt and elsewhere. With no indiginous people to walk on in our system, they could expand rapidly without harm.
Personaly, sign me up for the Jovian Company; hydrogen, helium-3, water, easy access to the belt, and a giant asteroid catcher.
Every mission I've seen, including NASA's, includes biologists and analysis equipment. If a biological threat is detected and infects the crew, they would likely be left in quarinteen on the surface or in orbit when the returned.
I am not sure how compatible life on Mars would be to life on Earth, with only one example, it is hard to tell. We based all our modles on planet generation on our own system only to find the majority so far which are entirely different.
They have one RTG left, and it is slated to go to Pluto. We should just buy some Pu from the Russians, or use some of our own, and build a few dozen more. They are not that complicated to build.
Do we even have the capibility of building an elevator capible of lifting from the Earth's surface to geosyncrinous orbit, everthing I have read has stated that modern material science is incapible of building a strong enough teather, even from pro-elevator sources. An elevator capible of moving payload from a low to a higher altitude is quite possible, and would be a good investment.
A HLV is needed to build an elevator anyways, so we need to concentarte on step one first. A cheep HLV would change everything.
NASA was origonally planning to use ISPP, but I don't know if they have changed the plan or not. The origonal idea behind the orbital gymnastics was that it would provide a more robust, secure rentry vehicle in case their were biologicals in the sample. It would probably be easier to shoot straight back to Earth, but that would require a larger sample module.
NASA was origonally planning to use ISPP, but I don't know if they have changed the plan or not. The origonal idea behind the orbital gymnastics was that it would provide a more robust, secure rentry vehicle in case their were biologicals in the sample. It would probably be easier to shoot straight back to Earth, but that would require a larger sample module.
You would need a prize 2-3000 times as large to make it worth the risk. I remember reading a book where someone did this. I don't think that this is possible in the next 30 years. Look how long it has taken to try to earn the x prize. Getting to Mars is a thousand times more difficult then a suborbital flight. It may be used as an encouragement for all the national space programs to get their acts together.
While it seams like a waste of resources for the retern of 10 kg of samples, one of the main goals of the sample return mission is to test technologies which are to be used in future human missions. Having the craft produce propellant on the surface, and rondezvous in orbit with a return vehicle are likely going to be included in an actual human mission. This way we can make sure our technology will work on the real, not a simulated, Mars before we put lives at risk. Nothing points out flaws in a technology faster then feild use, many ideas work out fine in the lab but fail in the field. I would rather it fail (i.e. what if curent designs for propellant maufacturing don't work on Mars for some reason, that would neccitate a change in plans) before we had lives depending on it succeeding.
By having the energy to send a smaller mass at a high dV, the same engine can throw a far greater mass at a lower dV. A high Wsp/high Isp propulsion system would be invaluble, capible of both rapid travel for people and slow high payload trips for unmanned cargo flights. I think we should always mininize flight time as it exposes the crew to radiation.
A HLV may get us into orbit, but chemical propulsion is hard pressed to get us anywhere else. A year in space should get us to Jupiter or Saturn, not half-way to Mars, and we don't need anti-mater to do that. To needlessly extend flightimes just to depend on chemical combustion is not the path to opening up the system to mankind.
We should have just launched most of it with the Shuttle C and added their few modules later. I bet shuttle C would still be a good idea today, particularly considering that most proposed HLV's (Ares, Magnum) are shuttle dirived anyways. They are already planning to maintain the facilities, and since prototypes have been built, and the engines, arguably the testiest part of a rocket, well proven, I say do it today. Having a HLV cannot be a bad thing.
Most concepts only had a limited number of spares. New spares could be manufactured, as raw material would take up less volume, but would require more equipment. Last time I looked, the surface hab in Zubrin's plan carried a 4 tonne margin for spares and contingency, with a .9 tonne spare and contingency margin on the TEI vehicle. Since two habs are to be sent to the surface, placing extra spares and tools in the initial one would be an effective use of mass, replacing expendibles used for transit in the manned hab. If something major breaks they might not be able to fix it, that is a risk one must take. Having some way of exiting the TMI hab for an EVA to allow small repairs, check the heat shield before aerobrakeing, etc. might also be useful.