quote:We live in an age where a $10 million, four passenger, carbon-fiber spacecraft can soar into space and re-enter the atmosphere and repeat the feat within a week of the first try. This "little spacecraft that could" accomplished this without thousands of ceramic heat-shield tiles that the shuttle requires. We live in an age where the scale model of an inflatable space station is successfully orbiting over our heads. Bigelow Aerospace of North Las Vegas has developed a full-size space station module that will be in orbit in a few years. These spectacular accomplishments were all done with private funds and the imagination and skills to make the impossible happen.
quote:NASA needs to reconsider its "Apollo on steroids," good-enough- is-good-enough approach and reach out to the Rutans and Bigelows and some of the old space hands to find innovative and cost-effective solutions to space travel.
Just think of the wonders that the United States could accomplish during the next 10 to 20 years as we follow our dream to explore space. Just think about the stimulation that these pioneering ventures would accomplish to attract our best and brightest young people into the fields of engineering and science. NASA should be leading the search for the best of the best rather than accepting the safe, but dead-end business as usual approach that it has chosen to follow.
quote:We live in an age where a $10 million, four passenger, carbon-fiber spacecraft can soar into space and re-enter the atmosphere and repeat the feat within a week of the first try. This "little spacecraft that could" accomplished this without thousands of ceramic heat-shield tiles that the shuttle requires.
Is he talking about SS1?
As I understand it their 65 mile jump (while technically into space) is not nearly high enough to generate the heat the shuttle does when it is falling at several times the speed of sound from orbit at nearly three times that altitute. His other complaints seem valid, but I don't think this one holds.
--j_k
[ September 17, 2006, 02:10 PM: Message edited by: James Tiberius Kirk ]
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quote:As I understand it their 65 mile jump (while technically into space) is not nearly high enough to generate the heat the shuttle does when it is falling at several times the speed of sound from orbit at nearly three times that altitute.
Yeah, I'm not sure about the technicality of that one. But the point: NASA's not doing its job, still holds. I'm reading a book by a space journalist, which I plan to post a review of when I finish, that discusses basically the battle that has been waged over the past two decades between NASA and the entreprenuial space community.
The entreprenuial community wants to move forward, and would love to have NASA's help, but NASA has been staunchly defending the status quo. As in, they tried to move forward with out NASA and NASA wielded its political and economic clout to kill their efforts. Meanwhile feeding money into Lockheed Martin and Boeing.
He's basically calling for NASA to cease and desist doing business as such. And I agree. Course... it won't happen unless very large amounts of the populace start getting on congress and NASA's back about it.
Posts: 3295 | Registered: Jun 2004
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posted
While I'm all for more interest and effort being put into privatized space industry, people need to understand that just as a matter of scale this isn't going to happen overnight on any kind of large scale.
As j_k mentioned, while SpaceshipOne is a great accomplishment it is absolutely no where near comparable to the shuttle or anything else.
This comparison is like saying: hey, the wright-brothers just got this plane to fly a few yards with one guy on it, why aren't they in charge of the commercial aviation industry instead of Boeing and Airbus?
one of the things that many people don't understand about the aerospace industry is that our designs really push the margins. i.e. to save on cost and mass etc the structure is just going to be a tiny bit better than it absolutely has to, the gas tank is going to be just a hair bigger than it absolutely has to etc.
Yes, there is some benefit to smaller companies working on this type of innovation, if only in the area of bureaucratic cost savings, but people definately have an inflated view of what is possible with private money.
And in terms of "finding the best of the best" by and large the best minds in aerospace are already there, working for NASA and the other big government contractors. Yes, pushing the envelope is great, but when you absolutely need something to work flawlessly for long periods of time with no possibility of repair or replacement, then you have to go with the tried and true technologies.
Much as this all is a science, a HUGE portion of the field is still based heavily on experimental results (i.e. we often don't know why this particular design works/doesn't just that reality has shown us the results to be so). So, when you decide to swap out a battery or processor or strut or gyro you may be getting better performance, or you may be throwing in something that's better on the ground but breaks down immediately in vaccum or zero-g or extreme temperatures or as it passes through the van allen belts etc....
Posts: 1038 | Registered: Feb 2006
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posted
[Deleted post because cannot put words together in intelligent, coherent manner while stoned out of gourd on wisdom tooth painkillers. Will contemplate later.]
posted
WHAT??? arnt enough of our heros and role models alrighty coming out using steroids?? berry bonds, lance armstrong and now even Nasas apollo program? when will all this drug use stop? i feel so dirty inside
Posts: 9 | Registered: Sep 2006
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posted
Sorry for the delay, its been so busy around here that I haven't been able to think in what spare time I have. Let alone do a response to this justice.
So here goes:
quote:While I'm all for more interest and effort being put into privatized space industry, people need to understand that just as a matter of scale this isn't going to happen overnight on any kind of large scale.
Cheers and agreed. Of course it won't happen overnight. But people need to start pushing now for NASA to give the smaller private endevoures(sp?) a little more support and to break up the big aerospace monopolies.
quote:As j_k mentioned, while SpaceshipOne is a great accomplishment it is absolutely no where near comparable to the shuttle or anything else.
That would be becuase it was a prototype build on a budget the whole of which was less than 10% of what it takes to send the shuttle on one mission. Of course it ain't gonna be anywhere near it. But it's on the right track. It's fully reusable, it has the turn around time necesary and EGADS it's so much cheaper than the shuttle it ain't even funny.
Sure it ain't a heavy cargo lifter, but it can lift people, which is much of what the shuttle has done: shuttle people to and from the ISS. Well SpaceShipOne can't do that. But the currently in developement (for a similarly low budget, I might add) SpaceShipTwo and the planned SpaceShipThree ought to be able to. SpaceShipTwo will be a suborbital, basically bigger version of SpaceShipOne. SpaceShipThree will be orbital, still using the same concept, just bigger and better. It ought to be able to handle transport to LEO.
quote:This comparison is like saying: hey, the wright-brothers just got this plane to fly a few yards with one guy on it, why aren't they in charge of the commercial aviation industry instead of Boeing and Airbus?
Here's where you really lose me. The comparison ain't even close. These people have worked on shoe string budgets and created fully reusable craft with the potential to make the shuttle, and it's insane expense, completely obsolete. That's worth a little, or if you ask me a lot of NASA funding and support. They're getting none. They have the potential to open space up like nothing else we've seen. The problem with space thus far has been the insane launch costs due to the shuttle and current line up of expendables. These guys are making fully reusable craft with crazy small turn around rates. That has the potential to drop launch costs out the bottom.
quote:one of the things that many people don't understand about the aerospace industry is that our designs really push the margins. i.e. to save on cost and mass etc the structure is just going to be a tiny bit better than it absolutely has to, the gas tank is going to be just a hair bigger than it absolutely has to etc.
What the frack are you talking about? The shuttle is pushing exactly no margins. It's twenty years old. And the planned Ares rockets are going BACKWARDS! They're falling back on Apollo Saturn technology that we actually FORGOT ABOUT. The engineers are having to study the Saturns on display in museums to reverse engineer the Saturn side of things becuase the plans for the Saturn were LOST! And the rest of the Ares is based of the same old THIRTY YEAR OLD shuttle technology. Gimme a fracking break. Not only that, but the Ares are expendable boosters. Thier cost will be comparable to that of other expendable boosters of today, which is: really freaking expensive.
Admittedly it will be nice to have heavy lift capability again. Which is why I don't personally advocate that NASA drop them entirely. But NASA ought to take a look at what the little guys are doing out there and feed them some support. It doesn't have to be much, a few million here, a few million there, a tiny fraction of NASA's budget could go a LONG way.
quote:Yes, there is some benefit to smaller companies working on this type of innovation, if only in the area of bureaucratic cost savings, but people definately have an inflated view of what is possible with private money.
Which is why NASA should send these folks a little FUNDING!
quote:And in terms of "finding the best of the best" by and large the best minds in aerospace are already there, working for NASA and the other big government contractors.
A few of the best of the best are. But they're bogged down in beaucratic bullshit and the politics of big aerospace and not truely allowed to use innovation. Big aerospace doesn't wanna innovate. They're getting fat off tax-payer dollars from the shuttle and the current expendables. They don't wanna lower launch costs cause that money that's spent for every launch GOES TO THEM! The best of the best who actually care enough about innovating have been in big aerospace, chaffed at the fact that big aerospace doesn't want to innovate and go anywhere, and jumped ship. They are now the ones building the K-1, building SpaceShipOne. They are the ones who built and flew the DC-X and the DC-XA. The ones who are trying time and time again to lower launch costs and make space viable and are getting shut down by NASA and big aerospace.
It's not even just that they aren't getting support it's that NASA and big aerospace are actively SHUTTING THEM DOWN!
quote:Yes, pushing the envelope is great, but when you absolutely need something to work flawlessly for long periods of time with no possibility of repair or replacement, then you have to go with the tried and true technologies.
Uh huh. And that's the shuttle? The shuttle that blew up and killed 7 people with in 5 years of its maiden voyage? The shuttle that 15 years a lots of upgrades later, fell apart on reentry killing another 7 people? I'm sorry, but when you're talking about our only real human access to space, I wouldn't call a 98% success rate in hundred missions killing 14 people "working flawlessly for a long period of time". Not only that, but consider that 2 out of 5 shuttles ever flown with regularity have blown up. No possibility of repair or replacement? We made a replacement shuttle for the Challenger. And the half the reason it takes so long between shuttle launches is that the damn thing needs so much check up and repair each flight.
Sorry buddy. Big aerospace and NASA have been screwing up for the last thirty years. And not only that, but they've been actively preventing other folks from having a go. Now other folks are being stubborn enough to actually get stuff the fly, it's time for people to take off the blinders and force NASA to give the little guys a leg up. Cause when they do, they'll find that the leg up they gave the little guys is returned 100 fold in lower launch costs. Which will open up the frontier of space as never seen before.
Personally I doubt NASA will change its ways. I doubt we can get enough people to care to force NASA to breakup the three way monopoly of Beoing-Lockheed-NASA and actually spend taxpayer money well instead of just feeding it into corporate contractors. I just hope to god that the little guys can stick it to the big aerospace, which it very much looks like they might.
If you wanna know more about the rockets I mentioned here are some wikipedia links on them. If you don't trust wikipedia, look at the links at the bottom of the wiki page, they'll point you to other sources:
posted
Not really. If you look at the their website (or the wikipedia sight lays it out nicely: http://en.wikipedia.org/wiki/JPL ), most of the missions they've sent out have been robotic probes. DS1 was an exception that tested a type of Ion Thruster.
JSC-ASP was working on a similar engine design (the VASIMR), and from the looks of it they sorta-kinda sold it, while still keeping it in house.
But before any of these engines will really be useful for human space missions, we need to drastically lower launch costs to LEO from what they currently are. Ares shows no signs of doing that. And the shuttle definately doesn't. These small corporately built and owned craft do.
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posted
How proven is VASIMR? Just curious, reading the description and it talking about directing the plasma exhaust by use of magnetic force fields sounded a bit high on my Star Trek-o-meter.
Is this something we can actually do, or is it theoretical?
And what steps, if any, have been made in increasing the speed of these vessels? Or, is the problem really one of fuel? If the VASIMR can travel at high speed for longer distances due to a reduced fuel requirement, it fulfills the requirement for increased speed.
Where are we on inertial dampeners? Hey, if we can have magnetic force fields, why not inertial dampeners? Or artificial gravity?
Posts: 21898 | Registered: Nov 2004
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Not magentic force field, a magnetic field. You know, the thing created by a magnet? In this case its very powerful electromagnet. Ionized plasma is electrically charged by definition, and anything electrically charged can be controlled with magnetic fields, since charges will spiral around the field lines. Pick up a physics 101 book and skip to the section on E&M, it'll explain it better than I could, though if you really want I can attempt to explain it.
quote:Is this something we can actually do, or is it theoretical?
They built a working prototype. They were still working out the bugs last I checked.
quote:And what steps, if any, have been made in increasing the speed of these vessels? Or, is the problem really one of fuel? If the VASIMR can travel at high speed for longer distances due to a reduced fuel requirement, it fulfills the requirement for increased speed.
Has to do with fuel weight. There is no 'speed' limit in space other than the speed of light. If you accelerate and then stop accelerating you'll keep going at the same speed, there's no air resistance to slow you down. So the only thing limiting max speed is the amount of fuel you have to carry. The more fuel you have, the longer you can burn that fuel and therefore accelerate, the higher your speed. The VASIMR has an insanely better fuel efficiency over the standard chemical engines of today, because it can use very light gases (hydrogen) as fuel. That's a massive mass drop.
**WARNING TECHNICAL INFO AHEAD**
Chemical rocket engines use liquid hydrogen, liquid oxygen fuel, with a ratio 2:1, hydrogen to oxygen. Hydrogen weighs about 2 kg a mole (H2) and oygen weighs 32 kg a mole (O2). So its about 4 kg hydrogen/32 kg oxygen. The VASIMR doesn't work on a combustion reaction so it doesn't need the oxygen. That's a lot of mass you don't need to carry, 8/9ths less actually. Obviously its not quite that simple, there's more to it (the whole combustion reaction has higher thrust, due to its higher mass flow, but plasma yields much much higher exhaust velocities and what both of those mean). But that starts to give you an idea of why.
**END TECHNICAL INFO**
The result is the VASIMR can accelerate longer on the same mass of fuel, and therefore obtain greater speeds than chemical engines.
There's a cost though, it doesn't have a high thrust by comparison. It can accelerate longer and over time reach greater speeds, but its basic acceleration isn't very high. And it's the base acceleration isn't strong enough for it to be useful in lifting things off the surface of the Earth. So, it's only really useful in going from planet to planet.
The ion engine is similar, but not quite as fuel efficient as the VASIMR. But it's fully operational, and the VASIMR is nearing that, so
Again, all of this is nearly useless though if we can't lower the cost to LEO.
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Incidently, we already know of a form of this we can use, if needed. But it's kinda clumsy, it involves spinning the ship Posts: 3295 | Registered: Jun 2004
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posted
I was quoting the article you linked when I said force fields. I don't really know the difference to be honest, was never much of a science geek (at least not for THIS kind of science).
Heh, I was looking more for the artificial gravity on Firefly or Star Trek, rather than that of Mission to Mars.
Posts: 21898 | Registered: Nov 2004
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quote:I was quoting the article you linked when I said force fields. I don't really know the difference to be honest, was never much of a science geek (at least not for THIS kind of science).
Fair nuff, sorry, I didn't actually read it too carefully myself. Just enough to figure out where the VASIMR was being housed. I've been kinda following it's developement since I first learned about it back in... 7th grade... 1999? 2000? Somewhere in there. So yeah, most of that info I can quote off the top of my head
As for the field/force field thing... they tend to like to spice things up sometimes. The difference in my mind is that force field brings up an image of a sci-fi shield or something... not the electrical and magentic fields they're talking about. Which is obviously did for you too. So they're being silly and trying to get publicity.
quote:Heh, I was looking more for the artificial gravity on Firefly or Star Trek, rather than that of Mission to Mars.
Yeah... no. Far as I know no one even has any realistic ideas for that sorta artificial gravity. There are two ways we know of that you could get it:
1) spinning the ship, make the floors be on the out side of the circle in which you are spinning (so feet facing away from the center) and let cyntrifical (sp?) force simulate gravity.
2) a constant acceleration, floors oriented towards the back of the ship (feet toward the ships engine, head in the direction you're going). But that's sorta unrealistic, since the fuel necesary to produce enough thrust to simulate even a fraction of Earths gravity is insane even with the VASIMR. (I think I once calculated that the fuel necesary to accelerate at 9.8 m/s^2 all the way to Mars was something like 500,000 tons of fuel. And that was assuming hydrogen and the most optomistic predictions of the VASIMR's efficiency. Granted, the trip would take about a week under that acceleration :-D )
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