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Six Minutes of Terror - Landing Humans on Mars
OriginalArlen writes "Universe Today has a fascinating article discussing the difficulty of executing EDL (entry, descent, landing) on Mars for vehicles bigger than MER, Viking and Pathfinder, and the challenges for manned craft in particular. Airbags can't be used for obvious reasons, but the atmosphere is too thin to be used for parachutes or aerobraking by large heavy vehicles. The stronger gravity (compared to the moon) makes an Apollo-style powered descent impossible. The best current idea is a huge inflatable torus called a hypercone: 'Imagine a huge donut with a skin across its surface that girdles the vehicle and inflates very quickly with gas rockets (like air bags) to create a conical shape. This would inflate about 10 kilometers above the ground while the vehicle is traveling at Mach 4 or 5, after peak heating. The Hypercone would act as an aerodynamic anchor to slow the vehicle to Mach 1.'"
We don't really have to land the large vehicle. Getting within transporter range should be enough.
Oh, wait...
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
Landing at mach one still sounds pretty fast -- better aim for water! Oh, wait ...
It is pitch black. You are likely to be eaten by a grue.
You say airbags can't be used, then propose what sounds like an airbag...nice
In a world of acronyms, the words are the real victims.
-dave
http://millionnumbers.com/ - own the number of your dreams
Sorry if I'm ignorant of some aspects of aviation technology, engines, or physics, but can't they use jet engines to slow it down, and then user whatever method that would otherwise be unusable at too high speeds?
Just extend the space ladder from Earth to Mars.
Dunno about the rest of you, but the Hypercone immediately reminded me of a rolled-up condom.
I wonder when that idea...uh...arose?
If they are able to land on Earth, what is the problem with landing on Mars? The main craft could be orbiting the planet, and something like "Endevour" would go to the planet and come back to the "mothership".
Would a space elevator be more feasible on Mars with the reduced gravity and atmosphere? Admittedly, you have to find a way to get a counterweight and cable all the way there, but it may be worth the tradeoff of the high speed landing with airbags, parachutes, rockets, and everything else we lug there to make it a slow crash. And surely rockets would be more useful than they say, otherwise, there's no way to get back off the planet.
Blah blah *studio in California* blah
Don't go to Mars, then none of the goverments will be wasting time nor lives. What is the need to go to Mars in the first place?
Look, if it is possible to take a craft like the armadillo to Earth's LEO and back, then it will be easy enough to do the same at Mars. And yes, it is in a moon style approach. Of course, it might be better to have a better fail safe approach to it, such as the hypercone.
I prefer the "u" in honour as it seems to be missing these days.
I did a project on this about a year and a half ago, and the solution we came to was in fact a parachute, but one capable of opening at Mach 2 or 3, similar to what Viking used. Unfortunately, since this has little use on Earth it is a very costly development process, and anything larger than Viking is significantly different, and a higher velocity opening speed would be nice. Following this a normal parachute, retro rockets, airbags or combinations thereof are still necessary.
Also, the problem with a retro rocket the whole way isnt just that its heavier gravity (just means more fuel,) but also the process of igniting a rocket with an incident airflow of mach 3 or higher is not a trivial problem.
Overall, Mars is the hardest place to land in the inner solar system. the Moon and Mercury are small and have no atmosphere, so Apollo is an obvious and easy choice. Venus has an atmosphere so thick you can drop any funny shaped item in and it will drop to the surface at low speeds, assuming the static heat doesnt destroy it. Earth, obviously, you can do well enough if you're careful with the shape and throw up some parachutes at the end. Mars though has such a thin atmosphere it makes everthing hard.
This concept sure looks interesting though.
If the problem is that you can't land the whole crew at once because of weight... why don't you land each member separately, in tiny containers and then a big load with the unmanned portion of the mission? Another advantage of something like this is that if one of the landings fails and you lose a team member your mission is still safe.
Do we really need to land heavy stuff on Mars? "Something heavy" here means some spacecraft with human creature comfort (you know, a hull, life support systems, etc... in order to keep wetware inside alive). However, there is no need for manned flight to other planets anymore: probes do a much better job more easily, at a fraction of the cost, and a probe's survivability is much less of an issue.
Probes are an extension of humanity's collective intelligence, and they bring back to humanity at least as much data as a real, flesh and bone human. So why send humans at all? Of course, if we're talking about colonizing Mars for good, there's some terraforming to do, but heavy machinery isn't necessarily required for that either, and it's not going to start within our lifetime anyway, and the planet won't be ready for us in 200 years minimum anyway.
I say forget about hauling big stuff over to Mars. The only folks who care are prez Bush, for demagogic purposes, and people who think watching a Neil Armstrong type character utter some silly piece of wisdom when setting foot on a planet is the pinnacle of human space exploration. What we need is more research into nanotechnology, so probes get smaller and lighter, and educating people.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
all these worlds are yours
except mars
attempt no landing there
This is how JPL intends to land the next rover, Mars Science Laboratory: http://video.google.com/videoplay?docid=1404791803 599052711.
Perhaps I am inclined to think things like this because everybody around me has an infection for which the only antidote is "robots", but... Robots!
We should send a massive fleet of robots down and they can build a runway of some sort. Once they've finished that, they can also build a little village complete with a bar. That way when people go to mars, they have a place to land, and then they can get a drink and maybe some munchies.
Dude, read the article.
All these ideas seem to assume a heavy lander is necessary. Pack 4 of everything since you want backups anyway. Break up all the parts of the habitation module and such into separate small pieces that break up from each other just when the atmosphere is encountered so they land in roughly the same area using already proven landing mechanisms. Assemble them with the humans still in orbit using proven rovers, robotics, and UAV technology (and with local humans, minimal time delay). Make sure environmental controls and life support are all on line. Then send down the humans in a much smaller vehicle.
Don't miss.
Redundant Array of Inexpensive Astronauts
How about a bunch of smaller craft, each landing on its own?
Send a bunch of supply craft and break the human landings up into one or two people at a time in smaller capsules.
As long as everything lands in the same area, (supplies first, humans last) then you just need to gather it together for your mars base.
Probably cheaper to launch several smaller craft anyway, and you could have plenty of supply redundancy.
...for OBVIOUS reasons? This is not so obvious to me. It will obviously feel kind of funky, but some of the amusement park rides out there are pretty brutal already. Now, I know you can't just drop them like pathfinder, but the last two rovers were quite big and complex, and NASA didn't exactly want them bouncing around all over Mars -- I'm not at all convinced humans couldn't survive that, especially in combination with a partially powered descent and parachutes. At the least we should be able to model this computationally, if not test it directly, even on Earth.
So. . a parachute then?
On a serious note, why not use a parachute? They've been used before on many missions to mars to slow the vehicle down before the retrorockets fired. I mean I understand the hypercone would work too, but I dont understand why a larger and/or more parachutes wouldn't. Then again I'm no fluidynamicist (is that a word because it sounds really really cool).
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
The 'airbag' approach means BOUNCING.
...'tracts of land'... it will probably never be safe for humans because we don't handle extremely high G impulses well.
Humans don't bounce too well, and neither does anything with too much mass (inertia). It was okay for the landers because they are much smaller than a manned spacecraft was.
(analogous to the oft-quoted maxim that you can drop a mouse from any height and it will survive, but a cat will not)
As the craft gets heavier, the size of the airbags that would be required to safely land it would I think increase geometrically.
Even with huge
Remember the last time you were in a aviation wreck going Mach 4 and the airbags deployed? I know I remember, and it was stained red all over the cabin interior from every passenger being ripped to shreds, including the airbags. Mars has an atmosphere that is extremely thin, so that's one factor going against using airbags since they wouldn't 'grab' enough of the atmosphere to slow the entry vehicle down to an appreciable speed before biting the Mars red dust. Using thrust burns up incredible amounts of energy and would be cost/energy prohibitive to be carrying that much of a fuel payload a few hundred million miles to Mars, considering more viable options exist. Those are two "obvious" reasons of many. Once NASA gets everything worked out, they will let you know.
Care to explain what a condom is to the rest of us /. geeks?
Nuclear.
The original moon missions involved _enormous_ rockets. Even if you could land on Mars what is the likelihood you would be able to transport rockets big enough to get you back off there?
Oh yeah, and have it work after being dropped from outer space.
Maybe if they used nuclear power to lessen the wight somehow, it _might_ be possible. Otherwise it's just a long one way trip with a slow cold end.
Why can't air bags be used? If the balloon bags that the last probes bounced around and landed with, were okay for all the sensitive equipment aboard, would they not be okay for humans? Or did those landers still take one hell of a beating, and were just tough enough to stand it? Anyone know the impact forces the gear sustained?
Love many, trust a few, do harm to none.
I'm sure they laugh at our measly doughnuts.
boycott slashdot February 10th - 17th check out: altSlashdot.org
that not only can we land on Mars, we can colonize it! It's just like colonizing America, only a little further! It's only a question of a little bit of entrepreneurial spirit and a bunch of volunteers!
Im in yr atmosfear
inflatin mi donut
mmmmm donutz
I suspect mach 1 on Mars is not the same as mach 1 on Earth (due to different speeds of sound in the planet's respective atmospheres). Which are they actually refering to in this case?
Is Mach 1 660 knots or 466 knots?
Add a wing, something that deploys like an F-14.
It's initially swept back for high speed/storage. Use gentle scissors
to bleed speed. Extend as needed to increase lift in the thin atmosphere. Then go from there.
Here is the video that the title quote originally came from. It's the EDL (entry-descent-landing) part of the Mars Exploration Rovers mission.
here, for now. (careful, it's not the fastest connection in the world...hopefully I can leave it up there for long enough for y'all to enjoy it :-)
There is no real reason to send a manned flight to Mars. None.
You would need to send enormous amounts of gear, several hundred tons of water
and food and air enough for the journey, the time spent on the planet and
the trip back. Exactly what would be the net gain for anyone? Bragging rights?
You would need a "mother ship" and at least two 'landers' with return
capability. In addition, a habitat for the humans. If you think you are a
treehugger, imagine the colossal amounts of resources needed to get there
and the environmental impact on Earth, just to start this type of endeavor.
Think people. That grey matter is supposed to be used.
Why not make a winged vehicle capable of making a controlled landing? Why does it have to drop down like a rock?
As the astronauts consider if the calculations were made in metric or imperial units.
Speaking of fuel, we've got Entry, Descent, and Landing, but what about Escape? I never seem to see anything mentioned about actually getting astronauts back to Earth after landing on Mars. Since Mars' gravity strength is a problem for landing, I'd assume it would be a bigger problem to get back off the planet.
Perhaps they'd also have to land extra fuel by the conventional airbag method, but even then setting up a craft for launch would probably pose quite a challenge.
I bet a flying wing would have the surface to weight ratio needed to land a light payload. You'd have to assemble it in orbit, and leave it on the surface. I mean, with less atmosphere you need more surface area distributing the weight of the reentering payload across the atmosphere.
With the old capsules they used a cone shape but in this case the cone would have to be really really wide on the bottom which would make it unstable. Something like the B2 shape I bet would be efficient enough to transport all that way and work.
Cool! Amazing Toys.
'Imagine a huge donut...'
Buzz Aldrin: Homer, what happened to the landing apparatus?
Homer: But it was so sweet and tasty...
We should focus on establishing a presence in space first. Let's get space working for lots of people, not just a select three at a time (plus celebrity). Think asteroid mining. Collecting hydrogen from the solar wind. Solar power arrays beaming clean energy back to Earth. Once we have refueling and industrial capacity in orbit or on platforms around the solar system, conquering the gravity wells of the other planets will merely be costly.
These opinions guaranteed or your money back.
Nothing for 6-digit uids?
Excellent! lolcode haiku. Will wonders never cease?
That's right, MARS, bitches!
come in fast and keep flying till you slow down..?
Before some startreck propellerhead invokes a familiar "Genesis rock" argument, here is a quick rebuttal. Yes there was "Genesis" group in the 70s, they don't play anymore.
We are talking about a journey perhaps couple decades from now, when robots embarrassingly defeat humans in chess, and robotic vehicles winning DARPA challenge. One can only guess what robotic abilities would be several decades from now.
I thought it was going to be a story about my sex life.
You may lose a couple... ok, but no one died right... Don't send people until you have enough stuff in the right place. Then send down the away team to search the mysterious caves for signs of life (I get a blue shirt and a thing that goes beep right...)
The lander only has to do the fancy schmancy transitional rocketeer low Gee delta vee stuff for the Humans. The primary risk is now missing the landing zone, and thus your supplies... so drop a few oxygen tanks a few klicks down-zone...
This may be much better that discovering a hypercone is as much use as a snowcone at mach 5, 10 klicks off the surface. Arriving with your supplies, at 100 metres per second... not a happy day.
So, drop the high G supplies seperately, in the same location, then the (insanely brave) people, preferably, in that same location.
This idea is of course copyrighted, patented and protected by the RIAA, DMCA and the FBI who will investigate all criminal copyright infringements (or thats what they threaten me with whenever I watch a vid)
I know someone at NASA thought of this already... but it's not mentioned in the article....Yep I read it, so shoot me already.
I guess they don't want to do it that way, because it's not the NASA Buck Rogers image, you know bravesouls in a pointy silver spacehip with big fins and a porthole at the top.
Frankly I don't see the need to kill people by sending them to Mars, and sadly, I believe we will in all likelihood, kill them. Our space tech is marginal at best, nor do we really need to go, this is not star-trek and shirt color alone may not save them.
I know, lets just fake the whole thing!, anyone got Pixar's # ?
There is no god; get over it already! Never exchange a walk on part in the war, for a lead role in a cage.
You could possibly use airbags if you moved the big thing down in pieces. The hardest aspect is that you'd want everything to land within a few miles of each other, especially important things like air and people.
10-20 G's. For an idea (not the full force), jump off the empire sans parachute.
I prefer the "u" in honour as it seems to be missing these days.
Why not simply have the large craft land unmanned, and have a smaller lighter pod for the passengers?
Heck, go all the way and have Starship Troopers style individual pods, with small retro's and parachutes.
I'm sure I read somewhere that such a study was done (by either NASA or the Russians), as an escape system - back in the day.
Would make for one heck of a ride!
Why not use electronic magnets in the opposite polarity.???
the journey to mars would take several months. These humans would consume the same amount wether in ISS or on the trip. Not a big deal (though better recycling does have to be developed). Once on mars, there is already water. It would give us fuel, water, and oxygen. Food would need to be grown. Again not a big deal. Assuming that anything meaningful there, will demand that we have at least a 1 year stay there. If so, then a small forward base will prbably be set up via robots first. Your issues are none issues.
I prefer the "u" in honour as it seems to be missing these days.
It's moderated as funny, but some type of nuclear thruster seems like it might solve a lot of these problems. It solves the problem of igniting a thruster in the face of a Mach 3 airflow. It solves a lot of the fuel weight problems. The same thruster could be used for landing, getting off the planet, and returning to Earth. And anyway, the only legitimate reason for us to go to Mars is if we want to become a space faring civilization, and the only way we'll ever really be a space faring civilization is if we develop nuclear propulsion technologies.
--------------------
Mailboxes Etc in Beverly Hills
Here's a video simulation of how the EDL vehicle would work.
And if you're the first people to make the landing (not saying you were the first to try) then you find out Mars is boring as hell and there's nothing to do. If you slowly go crazy turn to page 128. If you kill the rest of the crew members turn to page 301.
You're going to have a lot harder time landing on a body with no surface (or at least it's so deep we don't know where it becomes solid).
I'm a little bothered that the article dismisses as useless components that in actuality will probably be used for landing on Mars and are unrelated to the problem addressed in the article, and it tends to treat each idea as a complete solution, rather than pieces of a multistate solution.
The problem is not touching down on the surface. It's that first bit of decelleration during which you cover most of the distance to the ground. You've got to bleed off a lot of speed really fast, and Mars atmosphere isn't very conducive to accomplishing that. The article does cover this part well.
Previous landers, especially the Mars Exploration Rovers, have used multiple stages. The first is the heat shield. Because of their small size, the MER's have a high surface area/mass ratio. The heat shield slowed them down to mach 2 and a supersonic parachute deploys. Then retrorockets fired, slowing it to a complete stop a little ways above the ground, and lastly, the cable cut, dropping it relatively gingerly onto the airbags.
So just for the little MER's, there were actually 4 stages involved: heat shield, parachute, retro-rockets, and airbags. Although the article on focus on the airbags in its discussion of the MER, those were really only to allow a margin of error for the retrorockets (although a needed one), and were unrelated to the supersonic transition part.
The hypercone is basically a specially-shaped parachute, but it still won't slow a lander sufficiently to survive hitting the ground. I'm expecting the final solution if we ever commit to it will include heat shield, hypersonic chute, possible a middle stage chute, main chute, retrorockets, and airbags.
Also, you mention lighting a rocket in a supersonic airstream is hard (I'm not sure about that...the combustion chamber is static), and the article claims it would be better if Mars had no atmosphere. Regardless, if you're committing to rockets for anything more than what a modestly sized parachute leaves you travelling, then it doesn't much matter if you use the rockets down near the ground, or as part of a longer de-orbit burn. Either way you're getting rid of KE.
I think most /. readers will never get this but that hypercone looks like huge rolled up condom.
Stupid question, but...
The moon has no atmosphere. Mars does. Why not simply do like the Shuttle, descend through the upper atmosphere, slowing down past the "burn up" part, then just fly to the location in question? In the days of early flight, a landing field was ANY field that didn't have trees. With all our new fangled technology, one would think this would be reasonably do-able. If needed, send robots out ahead of time to clear a landing strip.
Add bonus, you have a vehicle that can a) carry something down with it, and b) get back into orbit with a little rocket assist...
MR T, Governor Schwartz and Silverster "those aren't my pills" Stallone think landing at anything less than mach 3 is for wimps!
These posts express my own personal views, not those of my employer
...when we should be thinking like Martians.
Mmm giant donut...
What is the speed of sound in the Martian atmosphere, anyway? This is what they mean by Mach 1, isn't it?
> The stronger gravity (compared to the moon) makes an Apollo-style powered descent impossible.
Ummm, someone better tell that to teams working on Blue Origin, DC-X, SERV, and the Kankoh-maru. They all do VTO/VTL on Earth. Two of them have already successfully demonstrated it. But hey, what would they know.
Maury
Could you do all the decelleration outside the atmosphere? Right from orbit burn off a whole lot of fuel and end up NOT moving across the atmosphere, just dropping into it. Then you've got to balance gravity with drag+thrusters at a manageable speed. I guess you gotta do the math.
http://dictionary.reference.com/browse/wight ... ..."little people" here...
2 3/2354213 they might need very limited biosupport if water is available locally to supply some volitiles...
so we're talkin' radioactive mutant
makes sense! smaller body mass, smaller integrated metabolic load requires less of everything
Hey! How about GREEN radioactive mutant little people (this IS Mars, after all!); they could photosynthesize!, In fact, if they could use their radioactivity as an energy source http://science.slashdot.org/article.pl?sid=07/05/
I apologise if this sounds overly harsh ( I , of coarse haf neffer maid a tai-poe...), but I didn't try to resist...
I would like to recommend a review of Clarke's Laws to anyone who takes "impossible" too seriously too soon http://en.wikipedia.org/wiki/Clarke's_three_laws
73
Then again, if a three-digit-/.-IDer in the robotics lab at CMU called me at 3 am and told me the sun was out - I'd just hafta go look...
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
I may be missing something here, and I certainly didn't rtfa, but we land stuff on Earth all the time, which has greater gravity and atmosphere than Mars, and that seems to go OK. So what's the problem?
Saying your "phone ran out of batteries" is like saying your "car ran out of gas tanks".
I've always thought that floating cities on Venus would be pretty cool. You wouldn't need to break that much, because at 50km up the atmosphere is already as dense as it is on Earth at sea level.
I would prefere NASA trying to land a probe at Uranus at mach 3.
All I can say is that I am amazed that this Wordpress-based blog survived a Slashdotting. A first!
Oh, and on subject - how did the Soviets deal with the issue? They first landed there in the 1970's: http://en.wikipedia.org/wiki/Mars_probe_program
Although they only put down landers with approx 1200kg mass, some of their solutions may scale to deal with the problems outlined in the article. Their solutions were also sure to be relatively simple and robust.
We have satellites and probes and robotic vehicles that could reach the top of Mount Everest and the North Pole too, but to say that there is no reason to send a person there misses an important point. Some people have argued that humans actual will gather crucial information that probes cannot - that humans with the same instruments found on Spirit and Opportunity could find confirmation of water or life on Mars in a matter of hours and whatnot. I don't know enough to judge that argument, but what I do know is that there is something awe-inspiring about send humans on perilous journeys of exploration that push the frontiers of civilization outward. You and I might be fine with the Chinese space program putting men on Mars before NASA, but a lot of people would give up every space science mission from now until 2100 to make sure that doesn't happen. It's an issue worth thinking about in terms that are not purely black and white.
A-Bomb
As recall from my former life as a rocket scientist, he did the design math for the Pathfinder Mars lander's airbag; supposedly on the back of a napkin, according to my former cow-orkers. It worked fine after a two-year trip through space. Seriously... he totally pwned the Mars Curse.
Of course, he's retired now, but he's still pretty sharp... I heard him flaming people 30 years younger than he is at a city council meeting last year.
why not send extra fuel packages there well before the manned mission? A set of fuel packages can be sent, something that will land on mars to be retrieved and installed on the ship to get out of there and then in orbit to get back home. This way we can send a lander that can use retro rockets as well as air baggy chutes and whatnot. Hell, send a set of robots to build some stuff before we get there for other support in landing.
Balderdash!
Or an inflatable wing? At high speeds, it could be a short jet fighter type of wing, and as velocity slowed, the wing would inflate more to provide more lift.
Or have two giant helicopter type wings. They could be rocket powered with rockets tethered on the end on the helicopter blade, to spin it and provide lift, if just the blades weren't enough.
Or how about a set of looong legs that expand out from the lander- say 30 meters. If the lander is tethered to the leg frame, a sustained 10g deccel could be done, slowing the lander from 80 M/s (170 MPH) to zero, as the tether is uncoiled/released.
..........FULL STOP.
Car accident 35 MPH to 0 in 2.5 feet. Broken ribs from my small 3 point seatbelt, wrist from steering wheel. Other hand didn't break, but left a fist imprint on my windshield (really cool looking).
0 06472
Indy/formula one/Nascar drivers routinely do more G's, but are strapped in better (neck HANS restraints), 5 point belts, wrist restraints.
Paul Strapp, MD, US Airforce did up to 40 G deccel (equiv to 120MPH brick wall crash) on a rocket sled, with various breaks, no perm damage. http://www.af.mil/history/person.asp?dec=&pid=123
..........FULL STOP.
This is the fundamental problem with the current "go back to the Moon, go on to Mars" space-exploration fantasy. It's not worth the trouble to send people to Mars if they basically have to immediately come right back.
When (if) we send people to Mars, they ought to be able to stay there and get some real scientific work done. The robots should have already cleared a landing field, built shelters, and extracted sufficient Oxygen for them to live there for a period of at least a few months.
Until we can do that, going to Mars is just a stunt. "We can't tell enough about conditions on Mars with the robot probes we've sent" isn't an argument for sending people, it's an argument for building better robots.
I'll tell you what - when NASA can keep half a dozen people alive for six months with no re-supply in a completely sealed habitat here on Earth (maybe on the Antarctic Plateau, to make conditions as close as possible), then they can use my tax money to start planning a trip to Mars.
Obviously what they need is a giant Zorb.
Maybe I'm wrong here, but while Mars's thin atmosphere makes for faster descents, wouldn't it also make for a lower ratio of velocity to parachute stress? The same parachute materials should be able to withstand stronger descent speeds on Mars than on Earth because the atmosphere is thinner.
However, it does seem clear that a much larger chute would be needed to provide the same amount of drag. Is there a practical argument against a really, really big parachute? Or multiple parachutes?
He who lights his taper at mine, receives light without darkening me.
There is no hard problem involved in transferring into a geosynchronous orbit on arrival at Mars from Earth, compared to the large problem of landing as a result of its thin atmosphere. It just takes energy, timing, and time.
Why do the people have to descend with or in the CEV and other equipment? Could the people go down using much smaller, lighter deployment method? Something like sci-fi stories where soldiers deploy from orbit in tubes, or perhaps some type of large wing opening after passing into the atmosphere.. Also, then if something goes wrong and deployment fails, everyone doesn't die together and part of the mission could continue.
Someone here mentioned a space elevator, which seems like an interesting idea. Perhaps by the time we're ready to go to Mars, we'd know how to build one. Is there carbon on Mars?
I'm no engineer, but I've heard stories of helicopters losing power and yet landing safely (if harshly) by allowing the rotor(s) to auto-gyrate. So -- how about we slap deployable rotors on top of that bad boy, and outfit the tips of the rotors with small rockets? You don't have to actually land under rotor power, just fire off the rockets at the tips to spin up the blades to provide enough drag to slow the vehicle to the point where a parachute becomes feasible. At the proper height, blow the bolts to detach the blade housing, deploy a parachute to slow the vehicle further, and then fire the retro-rockets to fine-tune the landing as in the moon mission.
Couldn't we toss our dogs into orbit, break off chunks of the vehicle that got them to the planet, and toss the pieces off and down to the surface via chutes, rockets or like the bouncing rovers got there? Then each craft with the humans in it could be tossed to the surface much lighter and hopefully easier to land gently than one huge annual supply load.
.. Toss them up there and pay for it later? lol
Just a thought. And hay, what happened to the mind set of the late 50's early 60's
Cheers.
It's a nice feeling to remove all the fat from my hard drive.
If a ship could drop a large number of "pods" containing people or supplies or machinery or whatever, each massing less than one metric ton, why couldn't the current methods work? It would be the Ikea way to get to Mars (some assembly required), but it would neatly dodge the problems of trying to land a single, larger ship. Some part of that ship could stay in orbit, and the contents of the pods (and maybe some recycled pod parts) could be stuck back together to generate the craft to return to the ship in orbit. That way the fuel used to get back to Earth is never landed on Mars, which saves the energy of having to get it back off Mars. Apollo 11 didn't land the entire craft on the moon, it only sent down the LEM. This would be more complex because the people would have to build their LEM once they are planetside, but the principle is much the same.
Mal-2
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
http://en.wikipedia.org/wiki/Space_elevator
Obi-Wan: "I felt a great disturbance in the Force, as if millions of voices suddenly cried out in terror and were sudden
Do we know more about the Moon than the Soviet Union because we sent astronauts versus robotic probes?
To be fair, the soviet projects probably costed 1/10 of what Apollo did. The Soviets had to scrap their manned program after a nasty explosion, and robots and automated sample returns were a consolation prize.
The idea is to get the brains closer to the thing they need to study.
But the Apollo experience shows that nobody knows much about a rock UNTIL it is studied carefully in a well-staffed (earth) lab. Thus a higher volume of semi-random rocks may be more scientifically useful than a lower-volume of human-picked ones. Plus, robots can more easily revisit areas of interest after something is found in the earth lab.
It appears that the equivalent science is roughly 1/3 to 1/8 the cost when done remotely. Humans may add drama and glory, but outsourcing the job to R2D2 is cheaper, I hate to say.
Table-ized A.I.
It depends on air temperature (which surprised me, I'd always been told it was pressure but it makes sense now I think of it). Wikipedia has a formula.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
Start terraforming mars using robotic probes. As the atmosphere density increases it will be easier to send ever increasing paylods which will provide more and more resources to increase the terraforming proccess.
Eventually the atmosphere will be thick enough to allow easier landing of big manned spacecrafts.
Optimal solutions would be to have an atmosphere thick enough to allow human live on the surface with no or little support equipment but with just a fraction of the gravity on earth.
Additional advantage of this would be the greater simplicity of landing vehicle. No need of very complex life support system and supplies.
This solution may take some time though.
Back in the 90s, McDonnell/Douglas developed a testbed for a "single stage to orbit" vehicle called the "Delta Clipper", aka the "DC-X". (Such a vehicle could take off from Earth's surface vertically, accelerate to orbital altitude and velocity, and decelerate from orbit and land vertically. Integral to such a vehicle would be an engine that is both easy to gimble, so that the direction of thrust could be easy to change for modifying the path of the vehicle, and also throttleable, so that only the amount of energy needed for each particular phase of an orbital mission would be consumed.) The DC-X was not large enough to reach orbit. Far from it. Its only task was to demonstrate its ability to perform the hardest task an SSO vehicle must perform: taking off vertically, translating horizontally, and then landing on a different pad than the one from which it ascended. We've done the hard part. The DC-X worked, and then the whole thing was killed by NASA's dead-bang incompetence. We ought to have a Single-Stage-to-Orbit vehicle operating NOW. And, if we did, we wouldn't be worrying about how we'd land on Mars. We'd just build an SSO tailored to Mars, take it there, and "use it in reverse"! Oh, and if we don't want to do that, we could just hire Burt Rutan to do it for cost plus 10%....
I've mentioned before that there are good reasons to push the development of the orbital elevator for Earth.
This is a perfect example of a human endeavor that certainly benefits from it. Not only is landing on mars a problem but getting back is even harder. at 5km/s escape velocity you are going to need a large amount of fuel if you are going to leave by rocket. You're going to have to have a vehicle of substantial size to carry and survive that much expendable fuel and resources.
On earth much of the difficulty is in raising an elevator the first time. But in Martian orbit none of that is a problem. You just tow an orbital elevator into position. There's nothing about the technology that says you can only go up an elevator. So you can slowly descend men and supplies as necessary. And you can go right back up the way you came without the need for expendables.
You also have lots of advantages on Mars working for the elevator. Lack of Lightning and threats to the elevator's structure. Smaller geosynchronous distance (50% that of Earth) so the tensile strength requirements are a bit less and the atmosphere is thinner which allows for more efficient broadcast of power via optical transmission to power the ascent vehicle.
I will never live for sake of another man, nor ask another man to live for mine.
Children are light and can collect rocks.
The Mach number depends on the speed of sound in the local medium, and the speed of sound in a gas depends on the pressure. Mach 1 on Mars (or in Earth's upper atmosphere) is much faster that Mach 1 at Earths sea level.
Deploy a large enough glider, and you will glide.
Your glider will probably be ripped to shreds, and then it's a long way down.
I'd rather spend a few hours circling the runway than six seconds ramming into it.
What you propose is somewhat like aerobraking, but this is a process that takes longer than just a few hours and carries some risk.
Geez, it was so easy in Forbidden Planet.
Put a hot babe with a pet tiger on the surface, the engineers will have a brainstorm in no time.
"You must try to forget all you have learned. You must begin to dream." -- Sherwood Anderson
http://www.aerospaceweb.org/question/atmosphere/q
There is no real reason to send ships across the Ocean Sea. None.
You would need to send enormous amounts of gear, several hundred tons of water because we don't have desalinization technology, food enough for the journey, the time spent in India and the trip back. Exactly what would be the net gain for anyone? Bragging rights? We already have a nice path around Africa, and maybe we'll be able to get Constantinople back as well as the Red Sea.
You would need a "mother ship" and at least two 'support ships' with return capability. In addition, a habitat for the pirates. If you think you are a treehugger, imagine the colossal amounts of resources needed to get there and the environmental impact on Spain, just to start this type of endeavor.
I reckon you could land an aircraft at a couple of hundred metres per second on the totally flat sandy plains at the Opportunity landing site. The area has been accurately surveyed from the ground and has (IMHO) the idea surface: a dusting of nice draggy dust underlayed by a hard sheet of totally flat rock.
http://michaelsmith.id.au
Is that Mach one at sea level one Mars, or Mach one at sea level on Earth? I think there would be a difference,...hmmmmm!
UNIX is truth, the Console is life. Use Evolution to send e-mail and not virii.
"Donuts; is there anything they can't do?"
Eat a Chicken, You know you want to.
At least this guy claims so:
http://youtube.com/watch?v=92_KmTkbfqM
Now what is all this? could it be possible? is the old guy any credible?
Such a development would make landing a piece of cake.
"Donuts... Is there anything they can't do?"
Grasshopper.
Try that on a motorcycle and you WILL see the difference between Asphalt and (soft cushy) water
Success is not the result of spontaneous combustion, you must set yourself on fire.
My suggested return vehicle would be a non-restitutable pogo stick.
:)
I figured this would be about 40 foot long for a human to survive a 120mph impact on Earth.
I don't know how fast Mach 1 is when landing on Mars, but if it's about 760mph then we'd be looking at a 250 foot pogo stick.
Whoosh
thud
SPROINGGG!
"Oooh, me back hurts!"
I like a good hyperbole as much as the next guy, but in this case "hydraulic despotism" is so over the top it's no longer funny.
Let's recap what it used to mean historically. It meant that your government can basically cut your only means of subsistence (as in, you _die_) if you disobey. Typically it was applied to water used for agriculture. E.g.,
- in Mesopotamia whoever controlled the sluices had, basically, the life and death of everyone else in their hand. That area was only able to produce enough food by irigation, so basically you obeyed or they could hurt you badly.
- in ancient Egypt, knowledge of the calendar was very important, since their whole agriculture depended on the Nile's yearly floods. So the priestly caste, who knew how to count days and calculate that kind of thing, accumulated disproportionate power. (Plus, used people's superstition to claim power over the river itself. You know, if you don't pay the priests well, Osiris will be angry and give you a crappy flood.)
Note that in both cases the punishment meant literally almost-guaranteed death, not just inconvenience or lack of privileges. As late as the late middle ages agriculture output was as low as 2 to 7 grains harvested per grain planted. So you'd have to work a large surface just to subsist and pay your taxes. Having your crop halved or quarterd because you were denied irrigation, would hit you _hard_. Chances are you didn't even have extra land or work power to compensate for that. And in early barter-based societies, that crop would also be your money, so you couldn't even buy much when something like that happened.
I'm sorry, but no resource imaginable nowadays comes even _close_ to that kind of life-and-death importance. And some of the examples used in SF stories (e.g., orbital rights) are outright laughable.
Also note that historically even this kind of despotism didn't work as well as SF authors like to pretend. Even with that kind of control, you can only push people so far before they revolt. The history of Mesopotamia and Egypt is full of revolts, invasions, usurpers, assassinations and other violent mishaps. The hydraulic empire didn't quite work half as well IRL as in, say, Dune.
Nowadays? Oooer. People might be complacent when it comes to minor deviations from the constitution, but I doubt that any (western) empire would have an easy time justifying to its citizens why it deliberately starved a city to death. I mean, look at the scandal around the government merely responding too late and too inefficient to the Katrina devastation. Now picture the government deliberately blockading a city and letting it starve. And flaunting it at that, because hydraulic despotism doesn't even work unless everyone knows you're willing to use that power. I doubt that even China could get away with it that easily.
So basically while it's a scary concept and makes for good novels... well, let's just say that so do Vampires, but you don't carry stakes with you IRL, do you?
A polar bear is a cartesian bear after a coordinate transform.
Those scientists are always trying to look at the hardest solution. Keep It Stupid Simple, use the old crap space shuttle to land. The "sand" should be enough hard to land without troubles, I saw some Hercules landing in the desert. I guess when a manned mission to mars will be conduct, we will have enough tech to make the shuttle takeoff like an airplane and then head straight for the space back to the mother ship (sounds like stargate here lol!).
We should think about just blanketing the planet with nukes to cause a massive climate change. Kind of like a jump-start for the planets weak weather systems.
Also, this could release gases into the atmosphere from the planets crust or something. There has to be some kind of brute force way of making the planet a bit more easily accessible.
You know... Do something useful with those nukes we have, rather than pointing them at our own people....?
Internet: Serious Business
What about landing in a massive dust storm? Now naturally, I see there are problems, but perhaps they are worth contending with. The advantage, is that the atmosphere will be full of relatively heavy particles to transfer momentum to. The disadvantages I see are the super-sonic sandblasting effect on the heat shield and the difficulty in navigating to your desired location. Since we don't know exactly what the dust is like on mars overcoming the sand-blast effect may be difficult. However, I think the navigation could perhaps be manageable given that the MERs are still able to gather some solar energy during one of the largest dust storm witnessed to date navigation by satellite should be possible.
i ty/20070703a.html
Any thoughts?
Here's a reference to the dust storm I wrote about: http://marsrovers.nasa.gov/gallery/press/opportun
Still won't work. Insulin is well out of patent, and its production is well understood and widespread. Water back then was something you couldn't just manufacture, and couldn't "smuggle". Insulin is nothing even remotely like that. So the only thing that government could do is, basically, spend a lot of manpower to try to suppress it by force, and create massive dissent in the process. It's just begging for a revolt.
And if it would even work... well, just look at the prohibition era, for how well _that_ worked. If it's too bad a demand, someone _will_ offer a supply. And in that case it was alcohol, which is at best a luxury and even carried some pre-existing stigma. Something that's life and death? Heh. An Al Capone smuggling insulin in that scenario, would get voted mayor and be the hero of the people. He'd have entire divisions deserting to his side, if he wanted to fight that government.
It's easier and cheaper to just shoot your opponents than try something like that.
Plus a lot of other social and economic conditions are entirely different. What worked back then, only worked because of the conditions were like that. It was a primitive economy, and more importantly an economy of severe scarcity. It was also a different era and culture, where people took for granted that the ones at the top have a right of life and death over their subjects. There was a severe lack of information, population mobility was extremely limited, trade was very limited and unable to overcome that kind of control, etc, etc, etc.
That's, in a nutshell, the stumbling block of all proposed "hydraulic despotism" scenarios. If you want a city dead, it's easier to just nuke it nowadays. If you tried to eliminate it by "hydraulic despotism" methods, you'd first have to pretty much blockade it with the army until it starves off, or people will bugger off somewhere else or smuggle stuff from somewhere else. At which point, why not just fire bomb it, then march your divisions right in and shoot everyone? It's going to boil down to a lot of shooting anyway, so you might as well get it done from the start.
Or you can do even better, and cause even less unrest, without any medicine conspiracy. You only need to look at the 20'th century for very conventional massacres which were kept reasonably secret and caused a lot less resistance and unrest. We have such conventional mass-murderers as;
- Pol Pot: just told people that they were evacuated because an American air raid was expected. (And the fact that that area had gotten more bombs per square mile than Germany in WW2 sure as heck helped make that lie believable.) So they peacefully got into the trucks, and were transported to the extermination camps.
- WW2 Germany... well, let's avoid that discussion for the sake of Goodwin's Law
- The Armenian genocide at the hands of the Turks in the last years of the Ottoman Empire: they just told those people they're getting relocated somewhere else. Sure, noone's happy to get deported, but it creates a lot less resistance than "omg, the government is trying to kill us." So until it's way too late, a lot of people are going to just comply.
Etc.
In a nutshell, we're already damn good at exterminating each other without "hydraulic despotism" methods. The "hydraulic despotism" scenarios add an unnecessary and inefficient level of complexity. Why would anyone realistically bother with that?
A polar bear is a cartesian bear after a coordinate transform.
I really did not know that.
I prefer the "u" in honour as it seems to be missing these days.
Duly noted, theoretically speaking it is an imaginable mode of failure. That much I'll aggree. It's not one I'd worry that much, though. And here's why:
1. It would have to be a particularly _dumb_ government that resorts to that. As I was saying in the other post, we already know much better ways to organize a repression than that.
And as a lot of modern oppressive governments discovered in the 20'th century, FUD (Fear, Uncertainty and Doubt) works _much_ better and cheaper than outright repression. E.g., the USSR post-Stalin didn't as much rely on outright oppression, as making people unsure who's an agent provocateur and what will be used against them if they say it. Basically it's better and cheaper to get the people too insecure to organize, than to do mass repression.
So, well, I'll reserve my fears for the future for smart governments, not to comic super-villain types that re-enact ancient societies (and presumably dress their legions of doom like Roman legionaires.)
2. Water despotism didn't even work that well as repression. It had to be backed by military threat anyway, or preople would just take control of the sluices and free themselves. And if the troubled history of Mesopotamia is anything to go by, it didn't exactly create long-lasted stability. Quite on the contrary. Empires went up and down like a yoyo, and it was one of the areas extremely hard hit by the catastrophe at the end of the bronze age. A lot of cities were razed and abandoned.
3. Water despotism was so successful back then, not as much because it's such a fearsome form of repression, but also because it was the only known way to organize a state. We're talking a very _primitive_ point in history. Humanity was just discovering how to work on bigger scales than a tribe, how to get people to pay their taxes instead of buggering off, or how to even know how many citizens you have and how much grain you're owed in taxes. The whole bureucratic mechanism didn't even exist yet, laws had yet to be invented (Hammurabi's code comes much later), it was some _millenia_ before nationalism as a way to keep people together, and even something as basic as a census or a map didn't yet exist.
Hydraulic despotism was, basically, one way to make it all work. Instead of bothering with all the organization, you'd just sell water for agriculture. That was your taxation, land measurement (instead of sending unpopular agents to assess how much land a peasant had, he'd come to you and say how many acres he wants flooded by you), incentive for the people to stay there, etc. It was a very primitive way to organize a state, more than anything else. The repression possibilities were just a side-effect. Admittedly, a nice side-effect, but a side-effect nevertheless.
In a nutshell, it was "successful" only in that it was the only competitor.
Basically, given that even the classical ancient empires were better organized than that, is another thing I base my assertion that it would have to be a particularly dumb government that tries to re-enact that. We already know to organize a state and collect taxes without basing it on selling that one vital resource.
I could go on about it some more, but it's already too late, and it's a huge message already. Basically I'm just trying to say that novels paint a very warped image of it. Historically it was a pretty complex thing, and there mostly as an early crappy solution, rather than as the ultimate scary government.
A polar bear is a cartesian bear after a coordinate transform.
Get a damn superpowerfull Drill (get it from Blendtec©) and take a trip to the mars core. Maybe you're lucky and find water.
I always thought the concept presented in the movie Red Planet (retardo movie, I know) was interesting.
Basically, they had this sphere that the crew climbed into, then it had gigantic inflated balloon things surrounding it. In the movie, their spacecraft was able to slow down enough to drop the crew container and have it just bounce once it hit the ground.
Of course that isn't an option, but what about an apparatus that was able to fire the crew container at close to the same speed that the craft is traveling downwards, but in the opposite direction (up)? Same idea as if you're in a falling elevator, jumping might prevent you from dying... A human can't generate enough force to mitigate the downward velocity, but wouldn't it be theoretically possible?
The other idea I had was a mini-space elevator. There could be a space shuttle type craft that orbits the planet and when the crew is ready to go down to the surface, the shuttle extends a super long, super strong cable that reels the landing craft down to the surface close enough to release them safely. Admittedly, the first option doesn't seem all that realistic, as the humans aboard would probably be killed by the G-forces required to counter the negative velocity, but the second option seems somewhat plausible.
Not only continents apart, but now worlds apart.
òò òó óò óó ôô õõ öö øø
The hypercone reminds me of an engineering class I attended. On the first day, we are handed an egg, some construction paper, scissors, and scotch tape. "Make something that can hold the egg and drop 20 feet--without the egg breaking". Of course, most everyone made some sort of brutish cushion. And, none of that worked. What did work? A simple cone. The egg was placed about 1/3 up of the cone to provide ballast and proper directional control. The extra construction paper was put at the top to slow the descent. When dropped... the cone descended--quite quickly (!), and then collapsed... the egg was safe. If the egg was put too far up, the cone would tip over and the egg would crack. Nonetheless, it was a simple and elegant solution. And, as far as I could see--the only solution out of about 30 different ones. BTW... my egg shattered on impact--surrounded by some construction paper. Oh if I had only stolen someone else's engineering design....!
The answer is simple: don't do that.
Method 1:
Ignite horizontally, above the craft. After ignition, rotate the nozzles 90 degrees and into the airflow.
Method 2:
Use the most powerful practical rocket design, the hydrogen boiler. (liquid hydrogen flows over uranium or plutonium, boiling it but not burning it -- skip the oxygen, which is heavy and corrosive anyway)
Can we use gas rockets to expand the donut instead of inflating it? Then in addition to the aerodynamic resistance you will get a floatation force as well. Donut will be "filled" with vacuum. Technologically harder of course.
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
Once we're able to freeze ourselves, we won't have to worry about reentry speed. We can be tossed around like a bowling ball until we come to rest much like the rover landers.
Failing that, use a big bunch of landers with rovers (each autonomous) each one carrying a small piece of the base to a rendezvous point. Have the base made before you drop the astronauts in individually.
Let's get some homework done before the technology is here. Build the base now with robots.
By the time its built/upgraded, drop in the astronauts using whatever method is most suitable in the future.
those stinkin Marsians are gonna get one hell of a sonic boom to wake them up.