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The Mars Society and people who support it need to organize themselves and operate more like lobbyists for traditional interests like the gun lobby and AARP operate on Capitol Hill.
Do we even have a lobbyist? Someone who can visit congressman or the president and talk on their own terms?
Can we afford one?
Mars Sem-Direct for me but I would like to make further modifications.
I would be interested in hearing them?
Do you have suggestions as to crew size? booster type? as well.
I think one of the problems with we Mars advocates is that we never fully settle on EXACTLY what we want.
We argue to long over whether Mars Direct is a "flags and footprints" mission plan or over whether a pressurized rover can be included.
I think we should decide with some finality on what type of Manned Mars Program we can support and ask the politicians to support.
Mars Direct? Mars Sem-Direct? Mars Hybrid-Direct? Four man crew?Five?Six?
In doing so, I think we need to consider the following:
1) What would the president be willing to support. There will be no Mars program without the endorsement of the president.
2) What would Congress be willing to fund? While we might like a 200 billion dollar program, we must be realistic what any Congress would fund and for how long once the go decision has been made.
3) How much public support can we get? For obvious reasons.
4) What will the NASA centers support. Johnson, Kennedy, Goddard, Marshall, JPL...........
Be realistic, no president is going to endorse a manned Mars mission if Johnson Spaceflight Center or KSC is telling him "we can't do that".
To that end, I think I would go with basic Mars Direct but with the Comet launch vehicle. Though instead of expanding the crew to six as NASA wanted expand it just to five and use the added lifting capacity to firm up the mass budget. I think that is the term.
Opinions?
Twenty people read this and not one replied?
I thought it was a dandy idea.
What about propellant for return to Earth. To use a buzz word, Trans-Earth Insertion (TEI). NASA's Design Reference Mission calls for bringing propellant for the return trip all the way from Earth. The great advantages of Mars Direct are aerocapture, and in-situ propellant production. That's why I suggested using the MAV as the TEI stage; giant propellant tanks so it would have enough fuel in Mars orbit to push the Interplanetary Transit Vehicle into Trans-Earth trajectory. Of course that would leave the MAV heading to Earth with the ITV. With a reusable MAV, are you counting on TEI propellant from Earth?
I don't know if Robert Zubrin reads this message board, but I know Maggie Zubrin does. Neither one of them ever post.
I figured on bringing the TEI propellant from Earth. Because I thought the whole point of Semi-Direct was to only have to produce enough fuel in situ for Ascent to orbit. So that if propellant production failed, then the mission could still be saved by launching a fully fueled Ascent vehicle from Earth to the Martian surface.
I would've thought the Zubrins would post somewhere given that Mars Direct has seemed to have been very must a "grassroots" effort.
It is been though of here before and I am sure Zubrin has thought of it. This is one of those technological improvements that can be done to mars direct to make the program more affordable. Zubrin based his proposal on current technology and said as technological advances come along they can be used to improve the plan. As for only using the MAV for two launches why? Use it for as many as it is safe to do so. The only question is do we invest in the development of a reusable mars accent vehicle or do we go right away. I am in favor of the technological development but some people are in a hurry. As long as we get there I will be happy.
The reason I suggested using the MAV for two launches only was because I figured it would have to carry along the hydrogen feedstock to manufacture all the methane it will use for ascent (and landing) during its original trip to Mars and I (not being an engineer) didn't know how many tons of hydrogen feedstock the MAV could carry to the Mars surface.
I figured that sometime in the first two mission time frame we would either have discovered ice on Mars to use or a small NTR would become available.
We all know what the Mars Direct mission architecture looks like.
And we know that Mars Semi-Direct is similiar except that it requjres a minimum of three launches instead of two because it splits the job of the Earth Return Vehicle (ERV) into two parts. With a Mars Ascent Vehicle on the surface and an Earth Return Vehicle in orbit that the Ascent vehicle docks with and the astronauts transfer to.
Now, one of the big problems seems to be the Mars Direct ERV. It has to do too much within its mass budget and ends up being pretty cramped for a six month trip back to Earth.
My change is this:
Why not make the Mars Ascent Vehicle REUSABLE?
That is, after it docks with the ERV in Mars Orbit, deorbit the MAV and send it to the projected site of the next Hab landing.
Now, the MAV would have to be a single stage to orbit vehicle, and would have to carry much more hydrogen feedstock to produce methane for subsequent missions, but I assume this is doable. Remember the MAV wouldn't need near the equipment that a full up ERV launched from the surface would.
And this MAV could probably be used as the ERV for long duration lunar missions.
Anyway, I would only make the MAV so it would be used twice.
By the time two manned Mars missions are complete (about five years) I would send a newer MAV with a small nuclear thermal rocket engine. All it would have to do would be to suck in a tankfull of CO2 to heat with the reactor and use as rocket fuel.
This way, after the first missions that emplaces the MAV (and one later that brings the nuclear power MAV), your Mars Semi-Direct Missions will require only two launches. One for the Hab. One for the orbiting ERV.
Is anyone going to read this?
Does Dr. Zubrin ever come online?
The ERV is clearly the biggest problem with Mars Direct. Its a manned interplanetary launch vehicle that needs a landing system for Mars, a nuclear power plant, chemical feedstock, a self-fueling system, fuel tanks, rocket engines, a crew compartment, radiation shielding, consumables, some way of landing on Earth, etc. There is a limit to how small and light you can make all of that, but in the Mars Direct plan it all has to weigh less than 30 tons. I am not convinced that we could make the ERV that light, and even if we could it would be very expensive and there would be a lot of things that could go wrong.
That is why NASA's Mars Reference Mission (a.k.a. Mars Semi-Direct) replaces the surface ERV with a simple Mars Assent Vehicle, and puts the ERV in orbit. This would require 3 launches per mission instead of 2, but it would make it much easier to stay within the allowed weight limit.
I wonder if going to Mars Semi-Direct would allow Dr. Zubrins proposed fully enclosed, life supporting rover to be included?
I understand why Dr. Zubrin liked the idea of a rover allowing shirtsleaved operations. The rover effectively becomes yet another "life boat" option on the Mars surface in case of a catastrophic failure of life support in the Hab.
But as far as exploration is concerned, the first missions could probably have plenty to do with a couple of internal combustion driven "Apollo type" rovers.
Radiation on Mars surface is roughly half that of ISS. Mars orbit is double ISS, but Mars has an atmosphere. His design included bags of regolith (Mars soil) covering the habitat roof. That is still sufficient radiation shielding. He did address the radiation question as soon as reporters covered results from the Marie instrument on Mars Odyssey, and pointed out the fact that reporters looked at orbital numbers, not surface numbers.
Objections about the ERV: he announced a Mars Society prize at the 2003 convention to redesign the ERV. Did you create an entry?
Mass estimates too low? He points out that NASA's DRM includes carrying propellant for the return trip all the way from Earth. That significantly increases mass. That's why he calls the DRM "Semi-Direct".
His design in 1990 included water and oxygen recycling with 80% efficiency; the Johnson Space Center's Advanced Life Support Project already achieved 97% water recycling efficiency. In "The Case for Mars" he stated NASA wanted to see 95% efficiency in water and oxygen recycling, but if we waited for that we wouldn't be ready until the 21st century! Wait a minute, it is the 21st century now. It appears we pissed away so much time the 21st century caught up with us. We now have the high efficiency recycling systems that NASA wants, so we can go now. But as for mass estimates, that reduces consumables below Robert's estimates.
NASA also plans for extensive suit consumables for EVA. I haven't heard Robert's response, but the original silver-zinc battery for the EMU (Shuttle spacesuit) only lasts 6 EVAs. A study in 1999 proposed an upgraded silver-zinc battery that would last 30 EVAs, but the cost was too high. Current lithium-ion batteries would last so long you could take every suit on EVA ever sol on Mars and it would still only use half its life. Consumables also include LiOH for scrubbing CO2, but the upgraded EMU for ISS already uses Ag2O as a regenerable sorbent. It could be made lighter by replacing the sheets with granules, and reduce power by replacing the electric oven with a microwave, but its already reusable. A mechanical counter pressure suit uses sweat to cool rather than a water sublimator. That means drinking water is the only suit consumable. The cold of Mars would reduce cooling requirement. All this dramatically reduces mass of suit consumables, bringing it in line with Robert's estimates.
Interesting information. Thanks. It appears that once again, Dr. Zubrin has crossed all the t's and dotted all the i's.
Dr. Robert Zubrin should be the NASA Admin. in my opinion.
I'm no scientist. Merely a history teacher and football coach. So I can't redesign the ERV. Though IIRC, I thought the original Mars Direct ERV was supposed to be capable of teathering off from the lower stage after escape from Mars and generating artificial gravity just like the Hab module does on the outbound trip.
On the other hand, if Earth Return takes place in zerio G, more of the internal volume of the ERV because usable as space and it would be possible for the astronauts to conduct the occasional EVA on the way back as a way of relieving boredom.
I think the stock market will have to rise to the 30,000 or so mark for there to be real chunk taken out of the deficit.
I hope he can accomplish his goals and achieve even more.
The way I envisioned Mars Direct happening, there would be at minimum one unmanned test of the Ares launch vehicle, just to see what it could do.
Given that Ares could lift 280,000 lbs. into LEO, I think it would be a great opportunity to send up a couple of unmanned probes weighing in the 5,000 lb. range along with their propulsion stages to send to Uranus and Neptune.
How long would it take JPL to put together a couple of orbiters, atmospheric probes, and moon probes for each planet? Given that size wouldn't be that big a deal, I think they could do it fairly quickly.
I seem to remember that the the Magellan probe to Venus was basically a leftover Voyager probe (plus some Mariner equipment) equipped with solar panels instead of RPGs and that the ill fated Mars Observer was a cobbled together probe as well.
On the way to Mars, Dr. Zubrins Mars Direct envisions rotating the Hab module and the upper stage of Ares to create roughly .38G (Mars gravity equivalent) for the crew.
Now, this equals Mars gravity, but given that all the outside work on Mars would be conducted with a fairly heavy and rugged spacesuit on, wouldn't it make more sense to condition the crew to about half a G to more accurately acclimate them to what they will weigh on Mars with Martian gravity PLUS the weight of their suits?
Especially given the astronauts work on Mars would include considerable amounts of heavy labor?
I've seen some objections to Mars Direct raised over the years and I've wondered if Dr. Zubrin has addressed them directly.
Questions such as:
1) What about the allegation that his mass estimates for the equipment and supplies necessary to support a crew on Mars are too low?
2) Is the proposed ERV really large enough for four astronauts for six months?
3) How does he address the new projections of radiation on the Martian surface being significantly higher than originally thought?
4) If NASA insisted on a six man crew per mission, how much larger would his Ares type booster need to be to get the job done?
Just some questions.
I saw a recent paper online that compared ESA and NASA cost estimates for the Mars Direct Program.
The NASA estimate for the Ares booster development was nearly THIRTEEN BILLION dollars while the ESA estimate was more than ELEVEN BILLION dollars.
These estimates were roughly one third of total program costs.
Why exactly is the development of the Ares booster, which uses variants or at most upgrades of existing STS tech so staggeringly expensive?
What would be the most expensive part of the Mars Direct Hardware to build?
The Hab module I think would be the most expensive followed by the Earth Return Vehicle.
Now, I think providing alot of space for the crew in the Earth Return Vehicle would be a waste. After all, they can be crammed tighter given the are
1) Coming home. Which will do wonders for their mental state.
2) Be getting closer to Earth, so communications with home will be much quicker the longer the mission draws to completion.
3) The crew will be returning to the ISS (presumably) for a brief quarantine and medical tests. Not to the martian surface for back breaking work all alone. So not as much space needs devoted to keeping them in top physical shape on the return leg.
What kind of price tag would we be looking at for a large booster. Say Ares type that Dr. Zubrin preferred?
I don't understand why it need be so expensive.
I heard it estimated that if they really put forth the effort, they could have an Ares type booster built for only one billion dollars within about a year.
I'm familiar with Ad Astra (National Space Society), The Planetary Report (Planetary Society) and Spaceflight.
Are there any others focusing on space exploration?
I really miss Final Frontier magazine. It was one of the nicest "mainstream" space exploration magazines.
I would prefer to not think about a "cheap and dirty" Mars mission. I would rather spend the time and money doing things correctly.
Wouldn't we all. But I think this is the trap alot of us space enthusiasts fall into. Thinking that we'll get a multi-decade, multi billion dollar program that methodically advances us into space fueled by an enthusiastic public.
In reality, I think any exploration beyond Earth orbit will have to be a series of "stunts" that we lobby for each individually.
How hard would it be to cobble together a "Mars Direct" style mission by modifying existing hardward?
For example, how difficult would it be to build a large booster by attaching four SRBs to a modified External Tank and mounting an upperstage on the top that uses existing rocket engines?
For that matter, how hard would it be to build a slightly altered version of existing ISS modules to serve as the "Hab" for transit to Mars and as living quarters there?
Lets say you diverted half the budget of NASA for 4 years or so. Surely you could do alot with 32 billion dollars (6 billion per year).
I like Dr. Zubrins statemnt "In the real world, you can buy alot with a billion dollars".
Say that in his 2006 State of the Union Address, President Bush announced that he wanted NASA to launch a manned mission to Mars by 2010....how would we do it?
Assume we had no notable advance in spaceflight technology over what we have now.
Assume a crew of 4 minimum-6 maximum.
Assume no major new launch systems.
Assume that NASA sets the acceptable risk for astronaut death at roughly 10%. (the risk estimated for the Mercury missions).
Could it be done? Could it be done with no significant increase in funds by redirecting the existing NASA budget?
I'm thinking a quick and dirty one off mission might be the best way to get to Mars in any reasonable amount of time.
And isn't this basically the method envisioned in Dr. Zubrins "First Landing" novel? I figured it was given that he had his characters come via a Venus flyby (not in true Mars Direct).
Let's say we discover life on Mars. Do you think that would speed up the process of getting a few humans to Mars?
Or are Americans too broke and too jaded to ever get excited about exploration again?
It will depend what Ben and J-Lo are doing that week.
I would want basically all American hardware. Call it 95% or more.
The reason is political. The more "internationalized" a manned Mars program gets, the lower the support it will get from the American people.
Diplomats and Washington insiders view "international cooperation" as getting other nations to help foot the bill.
Americans as a whole view "international cooperation" as the U.S. paying other nations to cooperate.
The two long duration lunar missions I put in there despite Dr. Zubrins aversion to them as part of a manned Mars program.
Why?
1) A "lunar base" is part of the Bush program so something that couples a manned Mars program to that is most likely to get support.
2) Scientific reasons. A four man crew spending six months on the moon can achieve many times as much as all six Apollo lunar landing missions.
3) Immediate return on investment. A "return to the moon" gives the American taxpayers something quick to point to that the program achieves. Important given that a manned Mars landing might not follow for as much as three or four years.
4) "Mentality" reasons. One scientist in Discover magazine advocating a mission to a Near Earth Asteroid mentioned this. He said he just didn't see the U.S. going from 40 years of missions in low earth orbit to the surface of Mars in one leap. I don't either. Oh I'm sure it could be done, but lots of people both scientists and layman would be uneasy at the prospect.
And yes, I would go with the Ares design, Shuttle Derived Launch vehicle as my steed of choice.
Although if I wouldn't be adverse to modifications to it that would still fit the KSC infrastructure if payload could be increased somewhat.
I plan to submit an article to the National Review and Weekly Standard regarding President Bush's plans for the moon and Mars. My article charges that the Bush plan is too timid and that all of his goals could be accomplished by following the Mars Direct program over a ten year time period.
I'm not that good with those kinds of details, could anyone here provide a ten year timetable of sorts?
Some notes:
1) The plan should begin in 2006.
2) It should include at least one (and probably two) Mars orbiters that would circle the planet in polar orbit to provide the best ever resolution of potential landing sites. These should be at least five years PRIOR to the manned missions.
3) The plan should include at least one unmanned "test launch" of the Ares launch vehicle.
4) The plan should call for two long duration (six months) lunar missions utilizing the Mars hab and a smaller version of the Earth Return vehicle. These should occur at least two years prior to the manned Mars missions.
5) It should stick with Dr. Zubrins original four astronauts per mission, two launches per mission plan.
Any takers?
In regards to Mars Direct, you've got to remember that much of NASA has always hated Mars Direct. And NASA of course has advised the president on Manned Mars Missions.
The reasons NASA has never liked it are legion:
1) It deemphasized the space station program. Lots of NASA managers have built their careers around the shuttle and station.
2) Many are appalled at the "bare bones" nature of the plan. Claiming that Zubrins mass estimates are way too low.
3) Like it or not, Robert Zubrin is an outsider, a maverick, a threat to the natural order of things (their view).
Look how NASA has taken Zubrins plan and altered it.
1) They went from Zubrins original two launches per mission to three (Mars Semi-Direct) then to SIX launches per mission. Including yet to be developed nuclear rocket engines.
2) They increased the crew size by 50% for no apparent reason.
Every time NASA touches Mars Direct, they make it bulkier and more complicated.
I like Dr. Robert Zubrin. I received one of the first copies of "The Case For Mars" on election day 1996 and it helped me get over the horror of Bill Clintons reelection.
That said, I've seen Dr. Zubrin many times on television and I would have to say that he makes a rather poor spokesperson for Mars Direct.
Its mainly physical. His voice is high pitched, his head bobs too much, and worst of all, his eyes blink way too much.
Blinking is considered by image and political consultants to be a very weak expression. They treasure politicians who can go a full 30 seconds without blinking a single time.
Like I said, I adore Dr. Zubrin. His Mars Direct Plan should be adopted in total and the first permanent settlement on Mars should be named in his honor.
But Mars Direct needs a more telegenic spokesman and advocate.