In April, President Obama urged NASA to come up with, among other things, a less expensive method than conventional rocketry for launching spacecraft. By September, the agency's engineers floated a plan that would save millions of dollars in propellant, improve astronaut safety, and allow for more frequent flights. All it will take is two miles of train track, an airplane that can fly at 10 times the speed of sound, and a jolt of electricity big enough to light a small town.
The system calls for a two-mile- long rail gun that will launch a scramjet, which will then fly to 200,000 feet. The scramjet will then fire a payload into orbit and return to Earth. The process is more complex than a rocket launch, but engineers say it's also more flexible. With it, NASA could orbit a 10,000-pound satellite one day and send a manned ship toward the moon the next, on a fraction of the propellant used by today's rockets.
It may sound too awesome to ever be a reality. But unlike other rocket-less plans for space entry, each relevant technology is advanced enough that tests could take place in 10 years, says Stan Starr, a physicist at NASA's Kennedy Space Center. NASA's scramjets have hit Mach 10 for 12 seconds; last spring, Boeing's X-51 scramjet did Mach 5 for a record 200 seconds. Rail guns are coming along too. The Navy is testing an electromagnetic launch system to replace the hydraulics that catapult fighter jets from aircraft carriers. "We have all the ingredients," says Paul Bartolotta, a NASA aerospace engineer working on the project. "Now we just have to figure out how to bake the cake."
How To Fly Into Orbit:
Rev Up The Rail Gun
A 240,000-horsepower linear motor converts 180 megawatts into an electromagnetic force that propels a scramjet carrying a spacecraft down a two-mile-long track. The craft accelerates from 0 to 1,100 mph (Mach 1.5) in under 60 seconds— fast, but at less than 3 Gs, safe for manned flight.
Fire The Scramjet
The pilot fires a high-speed turbojet and launches from the track. Once the craft hits Mach 4, the air flowing through the jet intake is fast enough that it compresses, heats to 3,000ºF, and ignites hydrogen in the combustion chamber, producing tens of thousands of pounds of thrust.
Get Into Orbit
At an altitude of 200,000 feet, there isn't enough air for the scramjet, now traveling at Mach 10, to generate thrust. Here spaceflight begins. The two craft separate, and the scramjet pitches downward to get out of the way as the upper spacecraft fires tail rockets that shoot it into orbit.
Stick The Landing
The scramjet slows and uses its turbojets to fly back to Earth for a runway landing. Once the spacecraft delivers its payload into orbit, it reenters the atmosphere and glides back to the launch site. The two craft can be ready for another mission within 24 hours of landing.
why don't they just mount this rail gun on the side of a mountain near a nuclear power plant, make it 10-15 miles long, and curve the last 3 miles at the end so that it shoots strait up, and skip the whole scramjet stage.
I believe this is how Dr. Heywood R. Floyd was delivered to the Space Station at the begininning of the book, 2001: A Space Odyssey.
@VoodooX i was thinking the same think, or one coming from underground just like intercontinental missiles? As long as its pointing straight up. I think maybe this is the proposed plan because they get kickbacks from the manufacturers of these scramjets. its all about $
With their country led by engineers as opposed to the West where nearly all our leaders are attorneys, China has a much better idea for a cheap launch system.
The Chinese could care less about greenies, so a modification of Freeman Dyson's Orion scheme is in the works to give them all the lift capacity for which anybody could ever envision a need.
Build a 2 mile long pipeline and sink it in the ocean two miles deep. Put a small nuke at the bottom in a put a thick steel plate underneath an automated payload capsule. Light the nuke and let er rip. When the projectile exits slam the door shut and redirect the radioactive steam into the water. Radiation leaks - a lot less than the daily radioactive output of one of their coal plants.
3000 tons at $10 a lb straight to the moon.
Great for compressibles like ice, steel,frozen food,fuel tanks, rocket fuel, circuit boards, nuclear fuel, copper wire and a thousand other commodities needed in space.
Humans and flower petals will have to be launched another way.
With the cargo capacity available, a simple very efficient space based transport could use the nuclear engines from stolen NASA Nerva designs since we aren't allowed to use them.
You're worried about a conspiracy by ... Big Scramjets. Yes.
No, the *point* is the scramjet itself. Launch something out of a rail gun and it will steadily decelerate due to gravity and resistance. It doesn't get you anywhere; it's a Wile. E. Coyote approach to space.
A scramjet can reach escape velocity before it runs out of air on the way up. The reason that they're using a rail gun here to launch it - and they could just as easily call it a mag-lev - is because scramjets can't operate below supersonic speeds. Ordinarily they have to be launched from other jets, rockets, etc. The rail gun removes that problem. But the scramjet is still doing all the heavy lifting once it gets started.
So here's ... my question. How exactly do you put *people*, which the article *specifically mentions*, on a device that accelerates to Mach 1 in *two miles*?
@VoodooX While it's counter-intuitive, you need more horizontal speed to stay in orbit rather than just climbing straight up. The space shuttle and other rockets only climb straight up for about a minute before tipping themselves over. Also, it'll let the Scramjet produce some lift which'll translate to more payload.
build it up the side of a MOUNTAIN. Without snow on top of it there are plenty out in california by 29 palms that i thought would work out great. about a mile high with some consistant elevation. On a maglev line would be ideal and the skateboard lets it go at the end of the track.
Radioactive waste produced by a coal fired power plant? Um dude, you're confused, last time anybody on this website checked, coal fired power plants don't burn Uranium, or Plutonium, or anything that is more radioactive than the graphite in your pencil... a NUCLEAR explosion at the bottom of the ocean would produce more radioactive waste than if all the coal on earth were burned at once...
And do you know why the Chinese won't put that plan you mentioned into action? Because they aren't idiots. All that radioactive fallout (from even one launch like that) would kill most aquatic life in the region, crippling most asian sea born economies. The fall of such economies and the lack of a large source of food would cause social upheaval, crippling probably entire societies, and I wager cause the start of WW3...
That said i'm pretty sure it's not "in the works" as you stated.
"No, the *point* is the scramjet itself. Launch something out of a rail gun and it will steadily decelerate due to gravity and resistance. It doesn't get you anywhere; it's a Wile. E. Coyote approach to space."
Actually if you get it going fast enough it would work its just we cant get anything going that fast yet..
99.9999999999999% of an atom is empty space
Why don't spend they're time and money in researching how to launch spacecraft by using electricity? If they can manage to do it with electricity it'll be far cheaper!
Interesting post! However, there is uranium in coal. Burning releases it. See gov't report here: http://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html
It's not necessary to have the rail gun pointed "up". A horizontal launch would be tangental to the Earth (it's round, remember)-- the further "out" you travel, the further "up" you are.
Also, consider that the idea is to launch an airplane. Once launched, the airplane (whether working off turbojets, or scramjets) would be able to change its angle of ascent. IOW, it could easily convert forward momentum into vertical climb.
Finally, the plan calls for a scramjet. Scramjets need to be travelling very fast, before they can be fired. A very fast horizontal launch, from a rail gun, followed by a boost from a turbo jet, would be the best way to get the scramjets up to speed. A vertical launch would require a lot more powerful railgun, to reach the required speeds.
I have a proposal that can do better than this, all the energy is used by ordinary trucks and pumping stations in getting mass on top of a hill. The mass generates acceleration the old fashion way, down a hill. It's called gravity assist, the old classic Galileo way of accelerating an object.
1/4 of the rocket fuel used on the space shuttle is expended getting up to 400 kilometers per hour the speed of a rocket launched sled using gravity assist alone to get up to speed, therefore a two stage to orbit space plane can be launched, this isn't rocket science folks this will really work it is about 400 years old technology, an object accelerates down an incline.
@VoodooX and @SKRIBE'
i don't think your proposal would be realistic for manned flight.
one of your assumption is to rely solely on momentum for the atmospheric part of the fly, which requires to accelerated the air/spacecraft to insane speed at ground level.
this will probably kill any pilot or passenger and/or melt the fuselage of the ship. assuming enough momentum will be left to reach 200.000'.
I'm surprised the author / PR writer used the term "rail gun". Later in the article the track is called a "linear motor", which usually refers to a very different sort of track.
Conventional magnetic levitation combined with a linear motor would probably be the best near-term tech for this sort of launcher. A rail gun is for launching small projectiles at very high velocities.
I guess they used the incorrect term "rail gun" to create a false link with recent news on rail gun weapons development...
A typical old tech 1,000 MW coal fired power plant releases more than 5 tons of uranium and 12 tons of thorium each year.
Even modern plants with ash capture still generate the waste, it is just stockpiled in the captured ash. This radioactive waste is due to the naturally occuring trace amounts of uranium and thorium in coal.
Here's a link that discusses it from a farily technical viewpoint:
Right, that's the whole idea here - the railgun just gets the engine up to operating speed. Voodoo, I understand that it would be *possible* to shoot things into space on a rail gun, but that's not what's being proposed here, it would take a hell of a lot more energy, and it would take a hell of a lot more than a two-mile track.
"So here's ... my question. How exactly do you put *people*, which the article *specifically mentions*, on a device that accelerates to Mach 1 in *two miles*?" (Dirk)
I could tell you to read the article, where it says:
"The craft accelerates from 0 to 1,100 mph (Mach 1.5) in under 60 seconds— fast, but at less than 3 Gs, safe for manned flight."
However, the article is obviously wrong -- or at least grossly misleading. A decent sport car could cover two miles in under 60 seconds, from a standing start; so, it is obvious that the launch is going to take a lot less time. If the craft is accelerating at a uniform rate; and reaches Mach 1.5 in two miles; it's going to get to the end of the rail in about 12 seconds. Sure, the article says "under 60 seconds" -- but, 12 seconds is a lot under 60 seconds.
That said, the rest of the article is correct -- 3Gs would do the trick, and it would be safe for humans.
concepts :) aren't they fun?
Using a railgun is a good alternative to launching a vehicle, as it wouldn't be as expensive to do, and it shouldn't require as much fuel. Using it throughout the entire launch is not so smart though. Simply put, why would you require more energy of the railgun when you could use the air already rushing past you to your advantage instead?
Scramjets work quite well in that regard ;)
Cool, but use a plasma rocket for the spacestage. Sounds great to me!
Now Fireball XL5 What ever next?
What about lifting a rocket to the edge of space with a balloon,and then lighting the rocket to attain orbit? It would cost a lot less than building a multi-billion dollar rail-gun launch system.
Good idea -- here's an improvement. Build the track up the side of a large mountain at the equator. If the mountain is 10,000 - 14,000 feet high, that drops the air resistance at launch time. The combined craft is already two miles high. Launching toward the East you get another 1000mph in the rotation speed of the Earth.
Landings are done near sea level so slower landing speeds are possible.
So that's my idea. I have a lot of good ideas -- all of them ignored.....
This idea is great, but has any body here thought about how to keep the plane on the track, or even centered? Because at 1100 miles an hour i would not want to catch that track.
You kids are all clearly stuck in the paleolithic age, teleportation is clearly where it's at.
I just say do away with the humans and have the thing shoot at full speed into space... the only thing human onboard are frozen cells and robots with an automated lab for growing and developing your future colony. Only problem is accelerating the development of the crew and training them to operate the ship - minor problem :)
There's also a problem with delivering that much electricity into the rail system. If the thing is burning 180Mw then you need to store a whole lot of energy in a system that can deliver it fairly rapidly without sustaining much damage. It's not something that can be plugged into the grid and fired at will. If you give it it's own power plant that detracts from it's efficiency since most large generators will need to be on for a lot longer than the 12 to 60s launch time.
In any case, whatever the cost is, we can expect it to be 10 times more expensive with the government holding the reins.
demonduck...i been saying this for some time too...powered by a nuclear reactor...its an idea that cant hide forever
No one here has mentioned the use of banks of capacitors along the track/rail line. they could be charged slowly reducing the strain on the power grid. Use a cooled superconductor to relay the trip signal with little to no resistance, also by using a cradel you reduce The overall weight of the craft. Build the system in the salt flats or desert with several mesa's. One other thing with an unmaned payload you could ramp up the intial velocity and use less fuel during flight or go from rail to rocket into orbit saving the scram jet for passengers flight.
Accelerating to Mach 1 over two miles is easily humanly survivable and I would guess the G loading would be well less than half of an aircraft carrier launch .
Shooting a space borne payload "straight up as some have suggested is foolhardy since that would make it impossible to enter orbit (which is just falling in an arc that perfectly matches the earth's size aka "falling with style")
"The craft accelerates from 0 to 1,100 mph (Mach 1.5) in under 60 seconds— fast, but at less than 3 Gs"
Hmm. At 3 Gs:
t = v/a
= 1100 mi/hr * 1 hr / 3600 s * 1609 m/mi /29.43m * s^2
= 16.71 seconds. Yes, that is less than a minute. A bit of an understatement there.
d = 1/2 a*t^2
= .5 * 29.43m/s^2 * (16.71 s)^2
= 4108.26 m * mi/1609m = 2.55 miles
but not a 2 mile track