So what are you proposing? What other viable technologies are out there? Do we not know a lot more about chemistry and nuclear physics than we did when we sailed the seven seas in wooden ships? You got some dilithium crystals stashed somewhere?
What’s amusing to me is that while these hypotheticals are interesting, the rovers are still operating. How fried by radiation and dead would our human explorers be by now? And how frequently could human missions be sent to Mars vs. robotic missions? And how much more advanced is each generation of robotic missions to Mars than the last one? And how good at navigating terrain will they eventually be? What changes in human biology will make them more resistant to the negative effects of microgravity, cosmic rays, cramped isolation, etc. during the same time frame?
Not at all, if the research is done to find out how to properly protect them.
Roughly every two years, just like with robots. The launch window is dictated by the timing of a minimum-fuel transit, not the nature of the cargo.
Depends on what they encounter. While the camera resolution of the orbiters continues to imporve our picture of the Martial terrain, it will be a heck of a long time before they can tell us from orbit what a lander can tell us from the ground. So the unnavigable terrain sen in one mission may (keyword: may) be surmounted at least 7 years later. I would guess that human ingenuity and a good amount of supplies and training would overcome it much more quickly.
As for incremental improvement, the MERs are rated for 300 feet per day. A person, whose Earth-developed musculature would seem superhuman on Mars, could probably cover the distance in significantly less time. The MERs top performace so far has been 725 feet in one day, which is longer than the combined length of Sojourner’s entire travels. So every seven years or more, the rovers get a little bigger and a little faster, but they are not particularly fast at this time. Check back in 2010.
Well, microgravity is only encountered during the six-month transit (Mars simply has less gravity than Earth, and anything develoed to work on a lunar base, if some people would get past the idea that it would just be a publicity stunt, would certainly be workable in Mars’ greater gravity). We’re already working on what to do about that with the ISS missions. Cosmic rays, same deal. Cramped conditions, ditto. And, FTR, I believe with the development of and acclimation to asynchronous online communities that is currently going on, isolation will be less of an issue. If it takes a half hour to respond to a message on the Dope, what does it matter whether the delay was due to light-speed transmission over a vast distance, or someone going off to watch a Gilligan’s Island rerun?
Very little of humans’ adaptation to new environments has involved actual biological change (Inuits’ developed preference for cold climates being a notable exception). Mostly just an adaption of technology and techniques.
What magical lightweight radiation-proof materials are we talking about, here?
A bit about radiation and a Mars mission.
A little more.
Why should anyone think anything resembling Orion is remotely up to the task of sending humans to Mars? And what’s the point of Moon shots in the current scheme, being a training leg for Mars shots, if our ships may not even be able to keep people alive during the trip, much less the stay?
This “well we haven’t solved that problem yet” can-do attitude seems to simply ignore some basic facts about materials, physics, and biology. It’s not defeatist to acknowledge reality, IMO.
Small summary.
“Flight by machines heavier than air is unpractical and insignificant,
if not utterly impossible.” - Simon Newcomb, 1902
“The demonstration that no possible combination of known substances,
known forms of machinery, and known forms of force can be united in a
practicable machine by which men shall fly for long distances through
the air, seems to the writer as complete as it is possible for the
demonstration of any physical fact to be.” - astronomer S. Newcomb,
1906
I await your cite that no possible combination of known substances, known forms of machinery, and known forms of forces are and shell ever be insufficient to the task, LD, and even then, that conclusion will be as foolish as Mr. Newcomb’s.
Are you trying to say that no new substances with the required properties can possibly be created, even given world enough and time? That a method of electromagnetically controlling positively-charged nuclei in the vicinity of a spacecraft hull can not possibly be found?
It’s not at all clear to me what the point of sending a person to Mars would be. What’s the ultimate goal, anyways? A self-sustaining colony there? Hell, we don’t have any self-sustaining colonies on frigging Antarctica. For the cost of sending the requisite life-support equipment we can send orders of magnitude more robots than people, with the added advantage that when the inevitable fuckups occur no one will die.
Frankly, if we’re going to spend many many billions on space, it should be spent on something that’s going to actually have some return. Like the space elevator. Dramatically reducing the costs of putting things into orbit would have far more dramatic consequences than sending a couple guys to Mars who would do more or less the same sorts of things the rovers are doing with more flexibility on the command and control end of things and a lot less flexibility on the logistics end. Hell, they’d probably end up spending most of their time jury-rigging their life support equipment in a desperate bid to survive until their return flight window opens, like that scene in Apollo 13 where there’s a collection of stuff piled on the table and the engineers are instructed to find a way to make a CO2 scrubber out of just that. Only for 2 years instead of 2 weeks.
I can’t see why the onus is on me to come up with the fantastic because someone in the past said something stupid. Mr. Newcomb’s statements were laughable the moment they were made, based on the known science of his time. I’m citing reports on the known science of today claiming we don’t even know if we can keep a passenger alive in transit to Mars using any imaginable feasible technology, and, even if we can, whether or not he or she will be able to function competently once there. How does the Orion program, or any forseeable program, address any of this, and what is the point of the expense of finding out?
I might also reference the cost and risk assessments of NASA managers during the nascent stages of the STS, and that program’s ultimate performance. The can-doers have had a piss-poor record of accurately representing the costs and risks of manned space flight at least since the end of Apollo, if not from its very beginning, whilst the direst predictions of the sceptics (roughly 1 in 100 failure rate) turned out to be the most accurate. And that’s just in the scientifically stagnant and utterly wasteful realm of LEO. Why am I the ridiculous one?
No, but they can become more efficient, cheaper to build and maintain, and reliable. Fixed geometry rocket nozzles have a peak efficiency at one particular ambient pressure which drops off rapidly as external pressure decreases. This is because the exhaust expands more rapidly with less ambient pressure (due to either higher altitude or increasing velocity) and thus does less work on the nozzle, translating into less impulse to the motor. Variable geometry nozzles (like the aerospike engine) give greater efficiency and use less fuel, thus increasing specific impulse and the fuel mass fraction for a given payload. While a LOX/H2 reaction gives the greatest specific energy output (H[sub]2[/sub] has a specific heat of 1.75 kcal/kg-K at the boiling point) it has a relatively low molecular mass relative to heavier propellents and thus exhibits high chamber pressures and sensitivity to nozzle configuration, whereas hydrocarbon bipropellent fuels like kerosense offer more thrust in a compact, reasonable pressure motor and not being cryogenic are easier to store (hence, the use of kerosene and LOX on the Saturn I, IB, and IC first stages, as well as Atlas, Delta family, Titan, Energia-Zenit boosters, et cetera.
Frankly, the biggest cost in performing a space launch isn’t the cost of the fuel–which for common fuels comes in at a few dollars a pound–or the materials used to construct the vehicle, but the development costs and operational/maintainence labor. This is particularly true of NASA, which has an entrenched bureaucracy to feed, and the aerospace contractors for whom the first priority is to spend the available budget rather than produce a viable product, which goes a long way to explaining the exorbiant budget of the CEV/Orion system, which consists largely of existing production components (STS-SRBs, RS-68 engine) and familiar technologies (blunt cone capsule, ablative heat shield) which shouldn’t require expensive development. (In the press conference following the CEV award announcement, one person questioned NASA’s selection of Lockheed-Martin SSC based upon their past performance and experience with space launch systems, which was an amusingly pithy observation as LMSSC has a reputation in the aerospace industry of repeatedly overspending development budgets and then failing to fly hardware.) In contrast, the Russian Space Agency launches of the manned Soyuz system cost an estimated $10-$16M per, illustrating the economy of using a relatively simple, mature system, albeit one that can’t be readily expanded to more extensive missions. However, the example demonstrates that space launches can be done far more cost-effectively than Apollo and the STS would indicate. Indeed, launches of the Gemini system atop a Titan II were a fraction of the cost of comperable Apollo earth orbit missions (albeit subsidized by using surplus Air Force ICBMs rather than a dedicated booster) and the cost estimates for Big Gemini, which would have accomodated a crew of six were substantially lower than Apollo.
The problem with the Shuttle was that there was really no focus on keeping launch costs minimized during design; the thrust of the effort was to keeping within the projected development costs (unlike the blank cheque policy during Apollo development, the STS was expected, upon threat of cancellation, to stay tightly within budget estimates) while having the system ready for deployment on schedule (1979) and meeting the myriad of expectations and capabilities laid upon it, including being the primary–and as it turned out, exclusive–heavy lift vehicle, having the cross-range for polar orbit launches for the Air Force and NRO, acting as a delivery truck for modules for the then-Space Station Alpha (the much grander concept that eventually became the ISS). and so forth. The many flaws, needless complexities, and labor-intensive operations were ignored in favor of getting something out the door on time, meeting specifications, and within budget. (Two out of three ain’t bad, I guess.)
As for Orion as the basis of a Mars mission, that is neither in the spec for CEV nor is it suited for such a mission. We have exactly zero experience with long term manned interplanetary missions, so to suggest that “we have the technology” is disingenous at best. We certainly have the ability–at enormous expense–to send a vessel to, say, Mars, but we lack the ability and experience to minimize radiation hazards outside of the Earth’s magnetosphere, nor do we have the experience to reduce the risks of long-duration missions to an acceptible level when rescue or assistance cannot be rendered. A vessel for eventual manned interplanetary exploration will be much different from CEV, and will require the development and maturity of technologies that are not even conceptually part of the CEV program.
At any rate, objective of Mars is, from both a technical and scientific standpoint, a poor return on investment. We can advance the prospect of a permanent, self-sustaining human presence in space, as well as acquire much valuable scientific information about the formation of the Solar System by first venturing to Near Earth Asteroids and later going to the outsystem (Jupiter, Saturn, the asteroid belt). Mars has some potential for planetologists and (perhaps) xenobiology, but the combination of inaccessability, low exploitability, and limited science prospects (compared to the exotic and diverse Jovian and Saturnian systems) renders the focus of landing on Mars as little more than a brazen stunt to attract attention and deflect criticism of the Shuttle and other unrelated current government policies.
Stranger
The sheer mass of the fuel is a cost in itself. The larger the spacecraft, the more fuel required, the more fuel required to lift the more fuel required, the larger the craft. The relationship isn’t linear, and eventually becomes insurmountable. This has been known for decades.
About the only technology we have presently to overcome the obstacles of interplanetary flight is nuclear weaponry. If you ignore international treaties, and ecological disasters, using nukes to send spacecraft to Mars and beyond is a clear winner.
What’s this all about?
From here.
What viable alternative technologies were available in the 15th century? Well, had they known, I suppose steam power WAS a viable alternative…they just didn’t know about it yet. Today? Well, there is the possibility of ground laser based technologies that could potentially be used to lift stuff into orbit. There is the possibility of fusion based technologies, or perhaps some exotic nano materials. If we do nothing but sit on our ass though we’ll never know, as technology will move in other directions. If we don’t GO to space, there won’t be any incentive to develop better ways…its a vicious cycle. Just like those wooden ships.
And yeah, the technical challenges of early exploration and colonization are pretty comparable to the challenges we face in space flight…relative to our given technical levels. In fact, a good case can be made that many of todays technologies stem from the needs to push early technology and science for things like navigation and the myriad OTHER problems that needed to be solved to allow those early explorations (accurate clocks for instance) and colonizations (preservation of food stuffs for long durations, long term nutrition and the links to the sailors disease, a.k.a. scurvy, development of greater logistics capabilities, etc). You seem to think this stuff was easy…and by the same token think that space travel is impossibly hard by contrast.
No dilithium crystals needed.
Well, there are two levels to this question IMO…what are the goals we are LIKELY to get, and what are the goals we SHOULD have wrt a Mars mission. Exploration of Mars isn’t the end unto itself…so you can’t really compare the cost of a manned mission to the cost of a robotic mission. Its comparing apples to oranges…unless the only thing you want to get out of it is simply study of the planet (or in the case of robot explorers the study of the planet within a few miles of landing). With a manned mission what we’d get out of even what we are likely to get from our government (i.e. a flags and foot prints mission) is the skills and knowledge TOO get men to the place.
We will have to solve Loopy’s radiation challenge…including the challenge of getting them there in the event of a major solar flare. We’ll have to solve the logistics of supporting them once they get there. We’ll have to solve the problems of landing them safely…and most importantly we’ll have to solve the challenge of getting them back alive and healthy. Sending robots solves exactly none of these problems. If you assume thats ok, then you assume we will never want to go…because if any of those magical mystery technologies ever DO come to fruition then we’d still be starting at square one…it would just be cheaper to launch, or we’d be able to have bigger craft. We’d STILL have to solve all the other problems…ones we CAN solve now if we decide to do it.
I think manned exploration IS an end in itself. Certainly we want to do good science…but as has been pointed out, robots do good science already. Let them do what they do best. And by all means, when we send manned missions out, send tons of robots TOO…robots that can be controlled by people on the spot so to speak. It will multiply their effectiveness and play to the strengths of both…because humans have certain strengths and weaknesses, just like robots do.
As I said, it boils down in the end to if we are going to be inward looking or outward looking as a people (i.e. the US) or as a species. I don’t believe that the entire human race is going to follow the Loopy’s of the world and be content to sit on this rock forever, not when there are vast resources out there. So, it comes down then to nations…will we, the US, who is in the best position globally to make great strides and secure our place in space, will we do so…or not. I think we SHOULD do so…but I don’t know if we WILL do so. The Loopy’s may win the day, and perhaps we here will live long enough to regret that. Or maybe not. 
-XT
Well, I’m not saying that we should never look into sending people to Mars. However, it seems to me that at the current time, our best bang for the buck, space program-wise, would be to focus on developing cheap heavylift technology. Like a space elevator, or whatever alternative might be feasible. Once we can move substantially larger payloads into stable earth orbits, then we’ll have solved a massive portion of the obstacles to getting to Mars. After all, if you don’t have such incredibly tight weight limits, solving the radiation and logistics issues becomes vastly easier. Cheaper access to stable earth orbits gives us all kinds of other immediate benefits too.
It’s not just a question of whether we should send people to Mars. It’s a question of whether we could do more to advance the space program focusing on something else. A manned Mars mission just for the sake of a manned Mars mission doesn’t seem to me like the best use of our space bucks.
For the most part I agree. I was only using Mars as an example. I’d be all over developing heavy lift capability, a space elevator, a viable presence in LOE (i.e. and international space station that is actually used and useful), etc etc. Maybe Mars ISN’T the best use of our resources at this time…though I do think we’d learn a lot by doing it. My only point is that IMO anyway, manned exploration is essential…as is robotic exploration. They are two different but necessary facets to the eventual goal of perminent human presence in space and the eventual exploitaiton of solar system resources.
-XT
I just don’t see the comparison. There aren’t any new elements to be discovered that I’m aware of. Carbon nanotubes are cool, but they’ve been cool for a long time and I’ve yet to see them alter realtiy. Our grasp of all the physical forces involved is good now to at least parts-per-million. Biology is a bit of a mystery, but thus far I don’t see any cause for optimism when it comes to the human capacity to absorb huge doses of cosmic rays and still function. I don’t think our ignorance of the challenges involved is anywhere near what it was in those days when people were afraid of falling off the edge of the Earth. I’d say the NASA cheerleaders haven’t been afraid enough for quite a while now, and typically overstate what we’re capable of, to the tune of many wasted billions.
One could easily have said that about computers in the 1970s. Carbon nanotube R&D is still in it’s infancy.
Myabe that’s because you’re not looking for it.
Sorry, folks knew the world was round when Columbus set sail, what they didn’t know was exactly what size it was, or that there was two large landmasses on the other side of the globe.
The billions spent by the space program are nothing compared to the billions spent by the government in it’s wars in Vietnam and Iraq. The technological benefits of the space program have been greater than those produced by the two wars I mentioned, and a helluvalot fewer people died in the pursuit of space than in those wars.
You’re making the big mistake that technology and knowledge will remain fairly static, even though it’s quite clearly the case that they won’t. Nor will the costs remain the same. Rutan’s work is progressing at a far lower cost than what NASA spent when they were doing similar things. And Rutan’s vehicles have much greater capacity than NASA’s did at the time. The onboard computer in SS1 is waaaaaay more powerful than what the Apollo capsules had (hell, your cellphone is more powerful), and also much less expensive. One of the reasons that computer costs have dropped so dramatically is that more and more organizations are pouring more and more research dollars into computing. Up until recently, the only people putting money into space craft was NASA and the Soviets. Now that private corporations are putting money into it, the costs are beginning to drop dramatically, plus they’re being funded by billionaires with cash to burn, and no annoying congress to answer to. I do not think we’ll see too many remarkable things coming from NASA’s manned program for the most part, but the private sector will continue to amaze us in the coming decades.