Slashdot Mirror
Nautilus-X: the Space Station With Rockets
astroengine writes "So we have a space station, now what? We've heard some rather outlandish ideas, but this is one concept a research group in NASA is taking seriously. By retrofitting the ISS with rockets, Nautilus-X will act as an interplanetary space station of sorts, including room for 6 astronauts, an artificial gravity ring, inflatable habitats and docking for exploration spaceships. When can we take a luxury cruise to Mars? 2020 by the project's estimate. It all sounds very 2001, but the projected costs of retrofitting the space station seem a little on the low side."
It's a damned cool idea. Probably won't happen, but still, an awesome second life for the ISS, and one that has an actual point to it.
Yes, a very cool idea. The only catch? Increased costs for resupplying the thing. Even at Earth-Moon L1, it's out much further than GEOsats, which are orders of magnitude further out than the ISS is currently at LEO. Funding the retrofit is one thing, funding resupply and ferrying in/out inhabitants is quite another. Besides, that thing would have to live outside the earth's magnetic field. Water shield or not, I'd hate to be out there during a CME or X-class flare.
ASCII tastes bad dude.
Binary it is then.
Hrm. Took me aback as well, that might just work with some serious modifications. Of course I don't see much point in going to Mars right away, we'd be better off concentrating on the mineral wealth floating around near to earth and using that to build orbital manufactories and further survey ships. Once we have a significant orbital infrastructure we can populate that level and look at going much further out, in style.
I mean I get the whole wonder of the mission and so on, but there's a reason man didn't go back to the moon. We need real economic incentives to build onwards and upwards, realistically. Once we're up there in force it's a whole lot easier to go anywhere else.
Actually, the Nautilus -X plan doesn't propose fitting "the" space station rockets and sending it to other planets (which would require making a goddamn huge rocket!), it proposes building "a" space station with rockets and sending it to other planets. The idea is to use a modular system that's actually built in space like the ISS to go to other worlds. Pay attention.
for long distance human travel is if we already had massive space stations at destination orbits.
You would only need to move human transport shuttles between stations, instead of transporting entire launch-shuttle-landing systems.
http://en.wikipedia.org/wiki/Delta-v_budget#Delta-vs_between_Earth.2C_Moon_and_Mars
It's about 1/3rd.
Those who fail to understand communication protocols, are doomed to repeat them over port 80.
The summary leaves out the most important part of the story: Nautilus-X is an acronym for "Non-Atmospheric Universal Transport Intended for Lengthy United States eXploration".
they aren't going to actually reuse the ISS, btw. They just put that in the article for people with no imagination, for which every modular spacecraft looks like the ISS.
A truss, with a VASIMR and a bunch of Bigalow inflatable modules attached is what they are proposing, as a lunar transfer ferry.
That might (probably will) happen SOME day, but i doubt by 2020.
Bad summary of what Nautilus-X is about, but the article itself fails in the opening paragraphs as well.
A better summary of the idea from physorg of the Multi-Mission Space Exploration Vehicle.
The idea is NOT about taking the existing ISS and strapping rockets to it. Nautilus-X IS about building something that would ride permanently in space out of technologies similar to what was used in ISS, along with inflatable modules such as Bigelow Aerospace's expandable space habitats. Separate crew modules would provide the ability to land and lift off from planets.
About the only part ISS itself would play is hosting a demonstration version of the ring centrifuge.
Pretty much the "real" interplanetary spacecraft as it has been discussed for decades, but Nautilus-X would be built with mostly known technologies.
I keep waiting for us to do something halfway exciting in space. Instead we blow our money on being world police. Screw all that. Cut the military budget in half and we could have a colony on mars.
I doubt we can afford this
NASA's budget for 2010 was ~18 billion dollars of a 3.55 trillion dollar budget. Making up a mighty half a percent of our budget. We can certainly afford it, even in these rough times. Whether it's a priority or not is up for debate.
I doubt if anyone will consider it seriously.
You are probably correct.
You do realize that despite the resemblance, this thing is not actually a Space Station. It's a space vehicle designed for interplanetary travel.
He says:
The Nautilus has a huge deep-space antenna where laser transmission may make more sense. It also has a shuttle-derived remote manipulator arm which also seems like excess weight.
As for the manipulator arm, yes, it is excess weight. Excess weight isn't necessarily a bad thing if you are already going to be lifting a lot of mass to orbit. If, say, one launch for constructing this vehicle required a Dragon, HTV, Progress, or some other supply vehicle to be lifted (for the purposes of a lifeboat, or some such thing), one could piggy back the manipulator arm on as an extra payload and outfit it to the new spacecraft. If the arm would require an extra launch then, yes, it is an expensive addition. However, in the event that this spacecraft would be landing a crew and then picking them back up again, the manipulator arm would not be unnecessary mass, but, in that case, a critical system for redocking surface-to-orbit ferries.
The oddest thing about that assessment by the author is when he says this previously in the article:
To significantly lower mass and therefore reduce transit time, why not simply send unmanned landers ahead and put them into a parking orbit to wait until the crew arrives.
If the spacecraft is supposed to be linking up with landers in a parking orbit at the destination, you can bet your sweet ass that a manipulator arm will be necessary to capture the landers. Of course, alternatively, the crew could also take a ferry to the on-orbit lander modules instead, but then you'd be carrying around the crew ferries rather than the landers and/or the arm, which means, again, a trade study should be conducted and the folks at NASA have probably already done so.
One other thing to consider is that while a higher mass requires a higher delta-v to hop from orbit to orbit, if the excess mass is a small enough fraction, it may not make a practical difference. Rocket engines that are in production produce a certain amount of thrust. If that thrust can boost "up to X many kg of mass to this delta-v" then reducing your mass below X is somewhat unnecessary, unless you need or want a higher delta-v margin.
It's important to remember that the first European colonists to North America didn't land on the East Coast and then drag race to the Pacific. Rather, they established a colonial foothold in the East first (like we should in LEO) and then, after developing their on-continent infrastructure some, they set off to explore further. Baby-steps lead towards progress. One off, epic publicity stunts lead to debt.
Motorcycles, Robots, Space Gossip and More!
Hahah, alright so. You construct an 11km high tower/launch ramp, a compressive tower the same as cell towers as a truss of smaller elements. A reasonable height-to-base ratiomight be 20:1. So a 10 km tower would have 3 base points 0.5 km apart, assuming you have a triangular cross section for the tower as a whole.
Each principal column would in turn be a truss with 3 sub-columns spaced 25 meters apart, which in turn are made of tertiary columns 1.2 meters apart and 0.06 meters in diameter each. The tertiary columns have a wall thickness of 0.03 meters. This puts you above the denser elements of the atmosphere. Its not nearly as hard as it seems, Frank Lloyd Wright designed mile-high skyscrapers back in the 30's.
Then you run maglev/railgun type vacuum tubes up the length of it, therefore using extremely cheap electrical energy to power the vessel through the first stage, which I think should put the ship into LEO at 7g, althoughyou'd probably still need a booster stage.
If you could launch at 10000 ft above sea level, you could reduce your velocity change to get into orbit by approx. 250 m/s. However, you need about 8000 m/s to get into orbit. A 3% improvement, which would actually be a serious improvement. A RL-10A has an Isp of about 450 seconds; thus, exhaust velocity Ve is about 4400 km/sec. Structure and payload mass fraction is exp[deltaV/Ve]; a RL-10A powered vehicle could achieve a maxium amount of structure plus payload to 8km/sec of 16.3%. Typically about 5% of this is actually payload. A 3% decrease in delta-V to orbit increases this to 17.3%. This increases the *payload* to 6% of the gross lift-off mass -- a 20% increase in payload.
Imagine the benefits of launching higher and a lot faster.
This has the effect of vastly reducing the cost to get to LEO and from there to proper orbit and eventually escape; if it was as cheap to get to orbit as it is to cross oceans, we'd already be on Mars.
So lets talk mineral wealth. The most detailed study of an asteroid, Eros, collected by NEAR shows that it contains precious metals worth at least $20 trillion. If Eros is typical of stony meteorites, then it contains about 3% metal. With the known abundance's of metals in meteorites, even a very cautious estimate suggests 20,000 million tonnes of aluminium along with similar amounts of gold, platinum and other rarer metals.
That is just in one asteroid and not a very large one at that. There are thousands of asteroids out there.
So once you make it economical to get up there, you need to build out an infrastructure. There are lots of theories on how to do this by aseroid resource extraction, I'm wavering towards the "rubble pile" asteroids which come pre-demolished, I can go into more detail if you like.
Let's be clear though, unless a launch tower would drastically lower costs to space, the initial buildout has to be for space and by space. Then once orbital manufacture has reached a sufficiently advanced level, you can send manufactured goods, worth many times their wieght in gold, straight back to earth markets.
/borrowed from many sources, I haven't the time to do the maths right now.