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Posted

instead of making a space ship that goes to the moon or to mars in a 1 shot deal, why not make a larger ship that would sit in earth orbit until its needed, in which case all nasa would have to do is boost up some equipment and fuel etc. and then send it on its way out. saving the cost of boosting a full fledged interplanetary space ship every time nasa wanted to go to anouther planet

Posted

Because it might be cheaper with resources to just use a reuseable craft every time rather than having to move fule, equipment and supplies up every time...

Posted

nasa is currently working on the CEV (crew exploration vehicle) which is supposed to be used both as a replacement for the shuttle and a vehicle to establish a permanent moon base by 2020. It is eventually planned that the same vehicle will be able to take men out to mars

 

but seriously with the cost of sending material into space what it is now I think it would be far more efficient to leave some sort of permanent booster in space, possibly using a nuclear thermal engine concept.

 

for reference the current cost of sending 1 pound into space is on the order of $1000

Posted

How exactly would this save fuel? You still have to get everything into orbit, if you do it over a period of time it may be more spread out, but you still have you use a ton of energy to get it into space. And once you're in space, why leave booster rockets behind?

Posted

because you could reuse the booster that took you to mars for all subsequent missions. assuming nasa went for a nuclear engine, they would save a huge amount of money on building multiple reactors

Posted

Leaving anything in earth's orbit for prolonged periods of time by itself is a risk. There are tons of space junk speeding around up there that are trapped in earth's gavitational pull and are moving at insanely high speeds. A stray bolt moving fast enough has enough power to puncture anything from fuel tanks to airlocks and render the thing useless.

Posted

huh wonder why the iss has an expected lifetime of 20 years, and even then it will only be retired because its no longer useful. not to mention the hubble.

 

Nasa has already developed a couple of technologies that can block against meteriorite impact. For instance the head of the deep impact (impacter) was made of a series of copper plates that succesfully withstood the barage of debris that came from its attempt to impact with comet temple 1

Posted

I for one don't actually believe that there are any aliens out there who have told us that we can't have interplanetary spacecraft. Does anyone wish to correct me on this thought? I thought not.

 

We needed to have nice little nuclear powered spacecraft in 1970. The simple fact is that if we had worked with this technology for 35 years, we would have 35 years of hands-on experience and R&D with it, and we could have had manned missions to the Kuiper belt by now, let alone the asteroid belt.

Posted
huh wonder why the iss has an expected lifetime of 20 years, and even then it will only be retired because its no longer useful. not to mention the hubble.

Not necessarily. If you built a modular superstructure with a slot-in system in mind, you could prevent obsolescence and allow easy upgrades with the latest word in drive technology.

Posted

I think normally when a space station (even if its modular) becomes that old its retired because it becomes cheaper to build a new one than tack on new modules, as evident by mir

 

also if you add new sections to the space station, it requires you reconfigure you plan for boosting the station back up to its orbit

Posted

This is all true, but we're talking about interplanetary technology so I'm guessing we have efficient boosting technology by then.

 

I would not use Mir as a counter example. Although modular, it was not built to be future-facing, and had a specified lifespan from the outset. We'd be building ours with the opposite design philosophy in mind.

Posted

Alternatively, you could just build it all in space to begin with. Then you could cut out all of the ineffeciency of lifting the craft, as well as any subsequent ones, AND any fuel, to orbit.

 

One of these days, I hope somebody with loads of cash decides to do this - maybe that will light a fire under NASA's pants. An international space race wouldn't be a bad thing, either.

 

My vote is for the space elevator that goes straight to the orbital assembly line!

Posted

problem with a space elevator, is that it would cost several hundred billion dollars to build in the first place. possibly several trillion. with the launch cost projected to go bellow $500 a pound pretty soon it will make the argument for a space elevator pretty difficult to make.

 

with the amount of material you could send into space without a space elevator for the cost of 1 you could probably build a whole assembly line for building things in space from the NEA's.

 

if your interested you may want to look up spacex and bigelow aerospace. there two companies founded by very very wealthy people for the purpose of either space launches or space manufacture

Posted

I don't want to sound like I'm going ballistic on you, but...

 

problem with a space elevator, is that it would cost several hundred billion dollars to build in the first place. possibly several trillion. with the launch cost projected to go bellow $500 a pound pretty soon it will make the argument for a space elevator pretty difficult to make.

 

About the elevator, this is just plain wrong. Based on a study by Bradley Carl Edwards, using current technology (or technology extrapolated about 5 years from current technology), a feasible, operational space elevator could be constructed in 10-15 years for a mere US$10 billion or so, including legal costs. A second could then be built for as little as $3 billion and with construction timetables compressed to as little as six months. Costs and construction time continually decrease after each elevator is built, according to this study.

 

Also, where on God's green earth are you getting your figures for launch costs?! Mine point to US $20 000 per kilogram for geostationary orbit, and $6-12 thousand per kilogram for low earth orbit. That's a LOT more than $1000 a pound, down to "$500 pretty soon." Any craft would have to be put even further out than geostationary.

 

Sources: August 2005 issue of IEEE Spectrum, "A Hoist to the Heavens" and http://ares.jsc.nasa.gov/HumanExplore/Exploration/EXLibrary/docs/ISRU/04Making.htm

 

 

with the amount of material you could send into space without a space elevator for the cost of 1 you could probably build a whole assembly line for building things in space from the NEA's.

NEA's? Forgive me if it's a dumb question, but what is an NEA?

 

And as to the rest: actually, no. Especially since "launch" costs could be potentially brought below $10 per kilogram with space elevators. To put the small figure of $10 billion into perspective, NASA's annual budget is $15 billion. The US government's annual budget (based on the Office of Management and Budget's figure for the current economy) is upwards of $12 trillion. So, with only a shade more than 0.1% of the US budget/economy, two space elevators could be constructed. The shuttle's launch cost is $400-500 million. The cost in launches for the ISS is much higher than that of building a space elevator, and the space elevator is a much larger structure (and, quite frankly, much more important) than the ISS.

 

 

if your interested you may want to look up spacex and bigelow aerospace. there two companies founded by very very wealthy people for the purpose of either space launches or space manufacture

In my own defense... You're forgetting a few. Scaled Composites/Tier One, the companies responsible for the first private suborbital flight by Burt Rutan's SpaceShipOne. Needless to say, I'm already pretty well versed in these companies. (I plan to become a private sector aerospace engineer in a few years.)

 

I don't mean to sound hostile, but it's a very common (and annoying) misconception that space elevators are immensely expensive and unpractical. They aren't, and we could start construction on one in less than five years, if the government was motivated to do so.

Posted

odd all the studies I had seen required the use of carbon nanotubules to construct, and who knows when those will become practical

 

interesting figures on the space elevator costs though, I'll read the study soon.

 

here's the sources for my launch cost numbers

 

wikipedia, gives the average launch cost for a space shuttle at 1.3 billion per launch (most of the wikipedia articles on space travel are direct copy and pasts of nasa articles, which are later formatted for wikipedia) can't find the launch cost per pound on the shuttle but I saw it listed as 1000-2000 dollars per pound

 

http://spacex.com/

that company is planning on achieving a cost per pound of $500 when they produce their heavy lift boosters

 

The two companies I listed are backed by people with hundreds of millions of dollars at their disposal, and have IMHO a better plan for expanding their operations than scaled composites does

 

also bigelow aerospace is building the first private space station, one of the modules for it is scheduled for launch next year.

 

NEA stands for near earth asteroid, these things are solid iron-nickel with "impurities" of platinum gold and other precious metals. they are also the size of the largest mineral deposites on earth, and all you have to do to get at it is cut a chunk of it off, and bring it back (a space elevator would be the best option for bringing it to earth). If only mining companies could see the tremendous oppurtunity that they have here, considering the start up costs of a mine run into the hundreds of millions of dollars

Posted
The two companies I listed are backed by people with hundreds of millions of dollars at their disposal, and have IMHO a better plan for expanding their operations than scaled composites does

 

So is Scaled Composites. A lot of their operations go into R&D. I'm not very familiar with SpaceX, though, so I can't really talk.

 

also bigelow aerospace is building the first private space station, one of the modules for it is scheduled for launch next year.

 

I was under the impression that if this launch takes place, it is purely a proof-of-concept / test of the design, and that the actual station will not be in place 'till around 2010, hence the deadline for Bigelow's competition.

 

NEA stands for near earth asteroid, these things are solid iron-nickel with "impurities" of platinum gold and other precious metals. they are also the size of the largest mineral deposites on earth, and all you have to do to get at it is cut a chunk of it off, and bring it back (a space elevator would be the best option for bringing it to earth). If only mining companies could see the tremendous oppurtunity that they have here, considering the start up costs of a mine run into the hundreds of millions of dollars

 

I absolutely and completely agree with you. There's BIG money to be made in space.

Posted

apparently bigelow is planning on marketing two versions of the station, a little one and a big one. The little one is pretty much a proof of concept but apparently they do plan on selling the modules to various government agencies and anyone esle who wants one.

 

anyway, scaled composites is attempting to produce reusable space planes. Spacex as far as I know has no plans for a space plane. Instead they are planning on building a series of boosters with the aim of dramatically lowering launch costs. They already have recieved a 100 million dollar contract from the air force, and assuming their test launch goes well they shall be well on their way to undertaking a significant portion of all sattelite launches. The company has plans for a series of heavy lift boosters that should have a launch cost per pound of $500. They also have plans to eventually produce man ready space craft that would be able to go out all the way to mars.

 

 

Spacex is also backed by the guy who made paypal

Posted

yeah, IMHO though the real money is in launching sattelites to orbit. Scaled composites so far isn't devloping that capability, at least to my knowledge. It requires money to succeed as a corporation and to build the space infrastructure required to make a space economy viable.

 

 

one note on the NEA's though, if we were to start bringing in resources from them wouldn't that cause the current prices for steel (which is already incredibly low), nickel, and any other materials available in space to collapse

Posted

It's possible, I guess. It just means more competition - and more jobs. Somebody's got to be responsible for the mining of the asteroids, too - even if robots do the actual mining, there have to be human managers and technicians. We are definitely not to the point of having fully autonomous mining facilities (read:AI-controlled mines).

 

Personally, I think there's plenty of money out there other than launching satellites to orbit. Tourism is a huge economy-booster throughout the world, and if it were fiscally viable for the average family to stay a week in space, we'd see a lot more "astronauts" out there.

Posted

robots don't need food or air...or water...or bathrooms...or living space

 

It's possible, I guess. It just means more competition - and more jobs. Somebody's got to be responsible for the mining of the asteroids, too - even if robots do the actual mining, there have to be human managers and technicians. We are definitely not to the point of having fully autonomous mining facilities (read:AI-controlled mines).

 

Personally, I think there's plenty of money out there other than launching satellites to orbit. Tourism is a huge economy-booster throughout the world, and if it were fiscally viable for the average family to stay a week in space, we'd see a lot more "astronauts" out there.

 

true, but will it ever become that cheap? bigelow aerospace is planning on charging something like a million dollars for a 1 week stay on their station. And, not to mention there isn't all that much to do in space. You go up, get completely awestruck by the earth, zero-G, and the myriad of other things you'll bear(sp?) witness to, but then its a week in something either the size of an suv (for a space ship interior) or a week in something not much bigger than a bus (space station)

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