Manned mission to Mars

[Lt. Rico]

Apologies if this topic has been exhausted already. To those of you with industry or engineering experience, (and even those of you without) how long do you think it will _really_ be before we send a manned mission to Mars? 20 years? 50 years? Longer?

If you ever read Stephen Baxter's novel "Voyage," it seems that we could have done it 20 years ago, at least from a purely technical point of view. However, IMHO, I think we need to wait until we have developed better propulsion technology and have done more research on the health effects and engineering challenges of ships with simulated low gravity. Forcing people to live and work in 0-G is stupid- it's worse than pointless, it's harmful- and I still don't understand why we haven't given up on it. And of course, we need to be in a better position to pay for it, since it would obviously be far more expensive than even Apollo. (Side question - what did the Apollo program cost, and what would that translate into today?)

So anyway, I think that means at least 30 or 40 years from now, perhaps longer. But that doesn't mean we should simply wait around until the calendar says 2043 - there is research we could be doing now that would help us get there.

Instead of the International Waste Station, wouldn't research toward this goal be a better way to pool our collective resources?

[cyswxman]

It's going to be quite a long time, I think. Mars is about 1000 times further away than the Moon. As a result a round trip to Mars would likely take over a year, and that's not spending much time there. I would venture to guess that a ship designed to house and feed even a minimal crew would be quite sizeable (I don't think something like the Apollo capsules would be feasible). There would have to be better ways for propulsion since, basically as I understand it, more mass means a lot more fuel which means a lot more money. As I stated in another thread (I forgot which one), I read where NASA did a study in the early 90's on the budgetary requirements for a manned mission to Mars and came up with almost $40 billion. I don't know how much that would be today. Nope, technologies would likely have to be improved significantly for this to become more that a thought experiment now.

[daver]

If we had to get to Mars we could probably send a manned mission there within a decade. This would involve all sorts of politically hazardous decisions, and would probably only be done if something major were discovered on Mars, like an alien artifact.

Outside of that, I'd put it at at least 50 years to a US manned Mars mission. China might do it earlier. I think for a US mission we'd need to see (1) a truly heavy lift booster (100-200 ton range) (it could be done without it, but ISS should have taught us that it's cheaper building a big booster than assembling a payload in pieces). (2) a rotating space station to study in particular the effects of long-term Mars gravity on people and in general the minimum gravity and minimum rotation period required for long-term (multi-year) missions. (3) long term (two years minimum) closed life support for a medium (6-12 man) sized crew. There are some other factors to be worked out, but those seem to me to be the big ones.

This all could be done within 10 years, but it probably won't be. For one thing, tether technology is promising to revolutionize access to space; it's going to be hard to get political justification for a big booster when, in addition to the usual detractors (money better spent on earth, man was not meant to fly, crystal convergence, just plain innumerate) a significant fraction of supporters believe it would be better to wait just a few years until tethers come on line. For another, cash is likely going to be in short supply for a long time, and a big space program is a conspicuous consumer (even though the actual numbers might be pretty low).

The last 30 years doesn't give me an awful lot of hope.

[Lt. Rico]

Daver, I think you're right- technically, we probably could figure out a way to do it within 10 or 20 years if we had the money and the politcal will, but realistically, I think 40 to 50 years is more likely, for reasons both technological and economic. I hope it's not much longer than that as I'd like to be around and still aware of my surroundings when it happens.

To what "tether" technology are you refering? The only space-related tether I have heard of is the 12-km wire deployed from the shuttle to conduct electrical experiements while dragging it through earth's magnetic field - sounded like a very interesting way to generate electricity while in orbit, but IIRC the tether broke before it was fully deployed and no further experiments were conducted. But I think you are talking about something very different that I haven't heard of before.

[SirThoreth]

I'm not holding my breath, waiting for tether technology. They're going to be a real pain in the neck to build, and I think, in the short term, BDRs (big dumb rockets) will be cheaper and easier to do.

BTW, 100-200 ton lift capacity isn't going to cut it. The Shuttle is100 tons - wanna go to Mars, and you're gonna need a lot bigger ship. Hence, Rombus.

Bono original design for ballistic single-stage-to-orbit (not quite - it dropped liquid hydrogen tanks on the way up) heavy lift launch vehicle. The recoverable vehicle would re-enter, using its actively-cooled plug nozzle as a heat shield. LEO Payload: 450,000 kg. to: 185 km Orbit. at: 28.0 degrees. Liftoff Thrust: 8,134,200 kgf. Liftoff Thrust: 79,769.00 kN. Total Mass: 6,363,000 kg. Core Diameter: 24.00 m. Total Length: 29.00 m. Development Cost $: 4,088.00 million. in 1964 average dollars. Launch Price $: 25.00 million. in 1964 price dollars. Cost comments: Reflight price -$ 25 per pound - after twenty flights. Bono expected the cost per flight to drop to $ 10 per pound ($ 10 million per flight) after 100 re-uses!.

With a 450 ton payload, something like Rombus would give us the capacity to build our Mars ship, although, even then, it might take a trip or two.

[eburacum45]

A big dumb booster!
One day these will have to be built- perhaps the Chinese will do it first;

if the disposable tanks go all the way into orbit they could perhaps be useful for all sorts of construction projects-

although re-engineering a fuel tank in space is unknown territory, and may turn out to be difficult in practice, there are lots of potential uses in space for an empty metal cylinder.

[Kaptain K]

...there are lots of potential uses in space for an empty metal cylinder.

Especially a big, airtight, empty metal cylinder.

[Swift]

I hate to say this but I agree with the general consensus. I think with a big, multi-national effort we could technically do it in 10 years or so (and even then with some serious risks), but I think there is virtually zero political and economic interest. I don't think the Chinese are going to speed this up, they seem to be taking a go-slow attitude.

I suspect the way this will happen is that the near-space stuff will happen first and ultimately this will be driven by commercial interests (go X-Prize). Twenty or thirty years from now there should be a serious, full-time human presence in Earth orbit because of commercial interests (not the ISS). Given that capacity, there will be a slow effort to first establish a presence on the moon and then ultimately Mars. But we are talking 50 years or more from now. I hate to say this, but I probably won't live to see it . I just hope the virtual reality entertainment is so good before then that I can experience it anyway. The brain part of Total Recall is going to happen before the Mars colony part.

[Dr Zoidberg]

How come no one's landed on the moon for so long? Is there nothing left to see? Maybe it was all a hoax :roll:

How hot is Mars' surface anyway? Could we walk on it with current technology?

[SollyLama]

Mars is certainly doable, but the hard part will convincing anyone (that controls the purse strings anyway) that a manned mission serves any purpose whatsoever. It'll only get worse as our probe technology increases and gets cheaper. Essentially all we're left with for manned exploration is so we can say we've been there, done that. Much like the moon.
And I tend to agree. The science we gained from the lunar surface with humans pales terribly to what we learned from disposable probes. There's no compelling reason to spend massive amounts of money getting a human to Mars when a robot will do quite nicely. In fact, it can be argued that insisting on human exploration is only holding our space program back because it increases the costs many-fold, as well as the danger. All for no more science than can be gotten from a 'bot. Certainly NASA took a bigger blow losing two shuttles than any ten probes they've launched.
A mishap with humans all but derails the space program for months or years until the investigations and congressional finger pointing is done.
It's a romantic notion of humans in space. But it's just not practical enough to be of much value currently.
I guess I'm with Dr. Robert Park (author of Voodoo Science) when I say the ISS was a monumental waste of money and resources. A Mars mission would be just as bad.

[daver]

Daver, I think you're right- technically, we probably could figure out a way to do it within 10 or 20 years if we had the money and the politcal will, but realistically, I think 40 to 50 years is more likely, for reasons both technological and economic. I hope it's not much longer than that as I'd like to be around and still aware of my surroundings when it happens.

To what "tether" technology are you refering? The only space-related tether I have heard of is the 12-km wire deployed from the shuttle to conduct electrical experiements while dragging it through earth's magnetic field - sounded like a very interesting way to generate electricity while in orbit, but IIRC the tether broke before it was fully deployed and no further experiments were conducted. But I think you are talking about something very different that I haven't heard of before.

There's talk about carbon nanofibers being within a decade or two of sufficient to build a beanstalk. I think they're further out than that, but there's a couple of interim proposals--a tether a few thousand miles long, the lower end of which is maybe a couple hundred miles high, and a rotating tether. The rotating tether could dock with essentially a high-altitude airliner--cost to orbit would drop to maybe the cost to hop the Pacific. The non-rotating tether wouldn't have quite as substantial an impact--it might lower the delta-V to orbit by a couple of km/sec, which would be sufficient to make a SSTO (well, single stage to tether) vessel practical.

If a rotating tether or a beanstalk look like they could become practical in a reasonably short period of time, spending money on developing a new booster technology becomes a complete waste--the booster would be nearly obsolete as soon as the tether came online. However, heavy boosters and non-rotating tethers play well together.

[daver]

I'm not holding my breath, waiting for tether technology. They're going to be a real pain in the neck to build, and I think, in the short term, BDRs (big dumb rockets) will be cheaper and easier to do.

I agree; i brought them up to point out that even the manned space supporters would be divided in their view of the best way to implement a Mars mission.

BTW, 100-200 ton lift capacity isn't going to cut it. The Shuttle is100 tons - wanna go to Mars, and you're gonna need a lot bigger ship.

Skylab was about 100 tons, and not designed to be particularly efficient. A Mars mission needs a descent module, an ascent module, a space habitation module, and a ground habitation module. These don't all need to be launched at the same time; i figured that 100 tons was about the minimum-sized piece. Obviously, bigger is better.

Hence, Rombus.

Bono original design for ballistic single-stage-to-orbit (not quite - it dropped liquid hydrogen tanks on the way up) heavy lift launch vehicle. The recoverable vehicle would re-enter, using its actively-cooled plug nozzle as a heat shield. LEO Payload: 450,000 kg. to: 185 km Orbit. at: 28.0 degrees. Liftoff Thrust: 8,134,200 kgf. Liftoff Thrust: 79,769.00 kN. Total Mass: 6,363,000 kg. Core Diameter: 24.00 m. Total Length: 29.00 m. Development Cost $: 4,088.00 million. in 1964 average dollars. Launch Price $: 25.00 million. in 1964 price dollars. Cost comments: Reflight price -$ 25 per pound - after twenty flights. Bono expected the cost per flight to drop to $ 10 per pound ($ 10 million per flight) after 100 re-uses!.

With a 450 ton payload, something like Rombus would give us the capacity to build our Mars ship, although, even then, it might take a trip or two.

Yay, Bono! I've been a Bono fan since I first read his book, maybe early 70's. As a result, i've never been particularly enamored with the shuttle.

[SirThoreth]

I'm not holding my breath, waiting for tether technology. They're going to be a real pain in the neck to build, and I think, in the short term, BDRs (big dumb rockets) will be cheaper and easier to do.

I agree; i brought them up to point out that even the manned space supporters would be divided in their view of the best way to implement a Mars mission.

Quite true. The question becomes one of "How long are you willing to wait?"

Waiting is a double-edged sword. Yes, in theory, the longer you wait, the more advanced and efficient your technology will become. However, the trouble we've kept running into, again and again, is that engineers, especially the ones at NASA, keep trying to make enormous leaps forward in technology, rather than smaller jumps. This approach seems silly to me - engineers, just like scientists, build on the work of your predecessors. Gradual increases, to me, seem easier to do than gigantic quantum leaps. Those enormous jumps only come by so often.

Look at the aviation industry, or the car industry. Yes, there are occasional massive leaps forward in technology (the internal combustion engine, the jet engine, etc.), but, for the most part, improvement comes gradually, a little bit at a time, refining this piece, improving that piece, rather than starting over from scratch each and every time.

Skylab was about 100 tons, and not designed to be particularly efficient. A Mars mission needs a descent module, an ascent module, a space habitation module, and a ground habitation module. These don't all need to be launched at the same time; i figured that 100 tons was about the minimum-sized piece. Obviously, bigger is better.

[i]Doh! Forgot to put in my response here. Skylab was around 75 tons, making it less massive than one of our Shuttle orbiters, actually. And, yeah, it wasn't all that efficient, but it wasn't bad, either. A lot of that mass was taken up by the Apollo Space Telescope, too.

As to how big a ship we need to reach Mars, it all depends on one question: what do we want to do there?[/url]

Yay, Bono! I've been a Bono fan since I first read his book, maybe early 70's. As a result, i've never been particularly enamored with the shuttle.

I learned about Phil Bono, oddly enough, on the Official Classic Battletech Website - a few of us in the forums launched heavily into speculation over there, especially after Columbia was lost, about how things might have been. The Battletech universe gave us a pretty broad canvas for some fictional "what ifs" to explore some of the ideas, what with the massive potential for "lost colonies", etc. One of the posters there, Cray, adopted Rombus as a launch platform for fission-powered shuttles based on the Lockheed LS-200.

BTW, a good site for "what might have been" can be found here: http://www.abo.fi/~mlindroo/SpaceLVs/Slides/index.htm. It makes for interesting reading. :-k

[Peter B]

How come no one's landed on the moon for so long?Is there nothing left to see? Maybe it was all a hoax :roll:

What are we going to do if we go to the Moon now? What we did in 1969 to 1972?

The scientific task assigned to Apollo was to determine the origin of the Moon. Courtesy of Apollo and some more recent lateral thinking by scientists and number-crunching by some computers, we think we have an answer.

How hot is Mars' surface anyway? Could we walk on it with current technology?

The surface of Mars is sort of similar to, but a lot colder than, the dry valleys of Antarctica. That is, most of the time the temperature is well below 0 degrees C.

IIRC, the biggest problem would be the damage caused by UV light.

[HenrikOlsen]

How come no one's landed on the moon for so long? Is there nothing left to see? Maybe it was all a hoax :roll:

Well, men on the Moon was largely a "we're better than the commies" publicity stunt in the first place, so once they'd been there the moneypinchers saw no reason to keep going.

Apart from the situations where it would be nice to have someone see why a probe failed, the advantages of unmanned probes are very large.

[russ_watters]

I know I've mentioned this before: in 1990 or thereabouts, I went to Space Camp in Huntsville and at the rocket center there they had a full-sized mockup of "Space Station Freedom" as it was called then. They also had a full-sized "Shuttle-C" mockup. That was to be a cargo version of the shuttle with double the lifting capacity (no wings, no re-entry). I'm pretty sure the name "Space Station Freedom" was coined during the Reagan Administration.

Essentially, Congress turned the project into a boondoggle which has taken decades to build and cost many tens of billions of dollars. If they had just given NASA $10 billion and said 'build us a space station (and if you need more money, let us know)' it would have been in orbit 10 years ago. That sort of attitude got the Apollo program and Manhattan project to work, but it doesn't ever happen in peacetime.

[daver]

Doh! Forgot to put in my response here. Skylab was around 75 tons, making it less massive than one of our Shuttle orbiters, actually. And, yeah, it wasn't all that efficient, but it wasn't bad, either. A lot of that mass was taken up by the Apollo Space Telescope, too.

As to how big a ship we need to reach Mars, it all depends on one question: what do we want to do there?

Yes, you're right, i should have rechecked my figures. Anyway, Skylab had a lot of wasted internal space and presumably mass. But it wasn't designed for long-duration missions either, and for only a three-man crew. 100 tons for two years for six people is probably low, but I expect two 100 ton modules would be reasonable and could be designed to snap together fairly easily. I don't know if 200 tons is feasible for aerocapture or not; i found a paper which seems to imply that 50 tons is doable. One problem is that the habitat module may not be particularly well shaped for aerocapture.

The task gets a lot simpler if aerocapture is allowed--you can use higher performance fuels (since the fuel doesn't have to survive the trip to Mars), and you don't have to carry your braking fuel. If you have to carry the fuel to brake into Mars orbit, your mass ratio looks on the order of 25, whereas it drops to a more reasonable 8.5 with aerocapture and low performance fuels, or 6 with aerocapture and high performance fuels.

If you can't aerocapture the orbital habitat, it might be worth investigating a cycler, or perhaps having two different orbital habitats (Earth/Mars and Mars/Earth), launched at different times.

A Mars mission can be launched in several pieces, you can hold off launching the actual manned portion until all the others have arrived and been verified as more or less operational.

A 100 ton to LEO booster gives you the capability to deliver 15+ ton packages to Mars with aerocapture, it might take nine or ten launches to lift and fuel a 100 ton package, 25 if it can't aerocapture. Being able to divide your mission into small chunks has a pretty good payoff--it could reduce your cost by a factor of two.

[Launch window]

NASA gambles all for a shot at the moon
http://www.eurekalert.org/pub_releas...-nga011106.php
On 30 December, President Bush signed into law a bill that endorses this vision for NASA.
But though Bush has said that NASA should resume shuttle flights and finish building the International Space Station (ISS) before returning astronauts to the moon, the reality for NASA's chief Michael Griffin is not that simple. He is under pressure to ensure a one-way transition from the old focus on flying space shuttles to the ISS to the new goal of building vehicles for the moon and Mars. "New programmes have very high infant mortality rates in the United States," says Howard McCurdy, a space historian and space policy expert at the American University in Washington DC. "Griffin has another two or three years to get the vision set down solidly enough that it can't be pulled out of the ground by the next administration."
What's more, Griffin has to do it with scant assurance that he will actually get the money to implement the vision; the bill that became law last month does not guarantee funds. Exactly how much NASA will get for this fiscal year will become clear in February when President Bush presents his budget to the US Congress for approval. And it is unlikely that the agency will get all it wants, given that the US is reeling from the costs of the war in Iraq and Hurricane Katrina. "There is no pixie dust in this Congress," says McCurdy.

Executive Summary (Introduction): NASA Exploration Systems Architecture Study Final Report (DRAFT) October 2005
http://www.spaceref.com/news/viewsr.html?pid=19066

A ride that's "Out of this World"
http://www.courier-journal.com/apps/.../1010/FEATURES
Rules are in the works to regulate space tourism

Design for Crew Exploration Vehicle Refined by NASA
http://bbsnews.net/article.php/20060111160110967

[Damburger]

It occurs to me that a mission to land men on Mars on return them is not worth the effort.

At some point we should think about a permanant base on that planet, as its a fairly good prospect for human occupation as planets go. But until then robotic exploration can tell us all we need to know. As far as I'm concerned, there is no point going to Mars unless you intend to stay on Mars.

[publiusr]

Rhombus is good--but will never be built. Sea Dragon is simple enough and rugged enough that it might be built for under a couple a billion if you get the right shipyard.