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NASA engineers are developing a radical new form of launch that begins aboard an electrified track similar to that of a rollercoaster.  (Source: NASA)

The sled would then fling a scramjet into the air, which would activate and rocket to the upper atmosphere. Once in the upper atmosphere, the scramjet would fire a capsule launch vehicle into space as the final step.  (Source: NASA/Artist concept)
New launch system could be used for manned launches and satellite launches

NASA's budget may be cut, but that hasn't stopped the first international organization to put a man on the Moon from dreaming big.  One key question the agency is looking at is what the next big thing in space propulsion will be.  NASA and foreign space agencies have examined plasma enginesion enginesnuclear-powered designs, and solar sails, but these technologies lack the impulse and thrust to accelerate a launch vehicle into orbit. 

However, NASA's latest proposal may be the most creative idea of them all and has the potential to be relatively affordable.  The new proposal starts by placing a sled on electric tracks -- NASA's sled needs to reach a whopping 600 mph (appr. 1,000 km/h).

At the end of the track, the passenger vehicle, which rests atop the sled, will be flung off, launching at extreme speed.  The passenger vehicle would be a wedge-shaped aircraft, with scramjets aboard, which would activate upon launch.  Those scramjets would accelerate the aircraft to Mach 10.

Wings would gradually angle the craft into the Earth's upper atmosphere.  At the boundaries of the Earth's atmosphere, the scramjet would fire the actual spacecraft -- a capsule.  The maneuver would be akin to firing a round out of a barrel

By using mechanical motion to launch the craft, instead of expensive chemical boosters, the cost of launches could dramatically decrease.

NASA's Stan Starr, branch chief of the Applied Physics Laboratory at Florida's Kennedy Space Center, says the technology to achieve this type of launch isn't that far away.  In a released statement, he explains, "All of these are technology components that have already been developed or studied.  We're just proposing to mature these technologies to a useful level, well past the level they've already been taken.  Essentially you bring together parts of NASA that aren't usually brought together."

Engineers at NASA and the U.S. Air Force have worked on a variety of scramjet projects thus far, including the X-43A and X-51 (a missile design).  So far these programs have had a couple of successful launches and tests under their belt, raising hopes that the technology can soon be applied to projects like the launcher.

Mr. Starr and other NASA engineers have assembled a proposal to build the system, which they're dubbing the Advanced Space Launch System.  They're seeking grants from a variety of sources.

Under the plan Langley Research Center in Virginia, Glenn Research Center in Ohio, and Ames Research Center in California would build and test the parts of the hypersonic aircraft.  Dryden Research Center in California, Goddard Space Flight Center in Maryland and Marshall, along with the Kennedy Space Center would engineer the rail track.  The plan calls for an actual two-mile long test track to be laid down parallel to the crawlway that the Shuttle used to be transported along to Launch Pad 39A.  Mr. Starr comments, "I still see Kennedy's core role as a launch and landing facility."

The 10-year plan for the launch platform calls for the program to begin with launching small drones -- like those used by the Air Force -- into orbit.  This would be followed by satellite launches.  If all goes according to plan, the system could eventually be used for low-cost manned mission launches, as well.



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Jumping to Conclusions
By FormulaRedline on 9/15/2010 12:44:43 PM , Rating: 2
Unfortunately I think DT has filled in some gaps in information from the NASA release and has created a misleading article. If the rail is only capable of acceleration to 600mph, the vehicle cannot be powered by a scramjet. A ramjet works by compressing (decelerating) supersonic airflow to subsonic airflow for combustion, a scramjet is similiar but the air is still supersonic (usually being decelerated from hypersonic speeds) during combustion. DT's claimed 600 mph of the launcher is well under even Mach 1 (~760mph at ground level), the scramjet would not light.




RE: Jumping to Conclusions
By mcnabney on 9/15/2010 1:11:17 PM , Rating: 3
The DT text combined some comments from the linked NASA article to get to that 600mph number. The scientist referenced that current accelerators are used on rollercoasters and that those rides run at velocities like 60mph. Later it is mentioned that NASA would be working on accelerators that would need to be at least 10x faster than current uses. Top Thrill Dragster at Cedar Point goes 120mph, 10x that is approaching mach 2 at sea-level.

I am actually really excited about this. Using electricity for initial acceleration and SCRAM after that is extremely energy efficient. It is also much safer due to the lack of oxidizer required, isolated fuel systems, and the ability to use the atmosphere to help support the weight of the craft instead of fighting it (along with gravity) when a rocket is used.

Combine that with a simple reusable launch vehicle and we are on the road to the commercialization of space. Space vehicles will look different though. I envision long, needlelike spaceplanes.


RE: Jumping to Conclusions
By mas6700 on 9/15/2010 1:21:30 PM , Rating: 2
Totally agree. When I worked on the inlet flow analysis for the NASP (National Aerospace Plane), back in the 1980's, I seem to recall the free stream Mach was well above Mach 5 before the vehicle went into SCRAMJET mode. So there's no way the vehicle in this article is going to be using SCRAMJETs to fly off the ground. That's ridiculous.

Speaking of which, what kind of passengers are going to be on a vehicle that accelerates from 0 to 600 mph in a space of two miles? Is that realistic? Seems like it would be a lot of G's. Then again, maybe not since dragsters can get to 300 mph in a 1/4 mile...


RE: Jumping to Conclusions
By bupkus on 9/15/2010 2:37:00 PM , Rating: 3
Interesting that NASA would essentially be using roller-coaster design software to measure g-forces in the upward curve from an initial horizontal track. Can you imagine at speeds of over 600 mph the force on the track not to mention one's brain against one's brain-pan directing this object upwards? Obviously, the ideal angle would be perpendicular to the earth's surface for the quickest escape from dense air friction but that would require quite a tall structure.

Imagine now the commercial and fun benefits in some really awesome new rollercoasters. ;) NASAcoasters! Now at 6 Flags!


RE: Jumping to Conclusions
By JediJeb on 9/16/2010 3:07:50 PM , Rating: 2
quote:
Obviously, the ideal angle would be perpendicular to the earth's surface for the quickest escape from dense air friction but that would require quite a tall structure.


Since the launch vehicle would be a lifting body using Scramjets you wouldn't need to go verticle at the end of the electric assist platform. A long smooth curve upwards to something over 45 degrees should work ok and not put all the g forces on the vehicle at the last moment.


RE: Jumping to Conclusions
By Jaybus on 9/15/2010 2:41:05 PM , Rating: 5
For a constant acceleration of 2 G (20 m/s^2), it would take 13.9 s to reach a velocity of 278 m/s. The distance traveled, given a constant acceleration, is d = 0.5 * (Vf - Vi) / t. Vi is zero, Vf is 278 m/s, and t is 13.9 s, so d is 1932 m. So for a 2 mile track, the acceleration could be a good bit less than 2 G.

BTW, top fuel dragsters reach accelerations of nearly 6 G.


RE: Jumping to Conclusions
By FormulaRedline on 9/15/2010 3:39:01 PM , Rating: 5
It's a good thing engineers do calculations instead of "listening" to the guy who said it "sounds" like a lot of G's.


RE: Jumping to Conclusions
By AssBall on 9/15/2010 4:47:05 PM , Rating: 2
Build the accelerator up the side of Hawaii. Make it ten miles long, and it will have a rise of say 2.5 miles. Make it a maglev to reduce friction (screw rails and wheels).

Most people who can pass a physical for a shuttle or soyuz trip can take 6-7G okay (more with respirators).

The advantages:

-you are close to the equator (get more centrifugal help from rotation).
-you have less air resistance the further you go up the mountain.
-you are already headed upwards 22 degrees at rail exit.

Given constant acceleration (and it isn't, of course) at say 8g, they would be going mach6 at the end. Unless I completely jacked up my math as usual.

Disadvantages:
-would need excessive power to operate.
-designing a ten mile accelerator over rough terrain and a several ton vehicle that can handle 3000 mph+ stabily.
-did I mention power? Dedicate a small nuclear facility.

Superconducting rails would be great for the messier effect, but they are even more power hungry once you cool them and expensive to build/operate.


RE: Jumping to Conclusions
By Manch on 9/15/2010 5:10:05 PM , Rating: 2
why not build near the poles. the troposphere is higher at the equator. 12 miles vs 4+. Does the centrifugal force overcome the amount of atmosphere that must be pushed trhu? If anyone knows the answer or a link post it.

thanks


RE: Jumping to Conclusions
By AssBall on 9/15/2010 8:28:18 PM , Rating: 2
Launching from the poles would put you in a weird ass orbit though.


RE: Jumping to Conclusions
By roadhog1974 on 9/15/2010 8:43:53 PM , Rating: 2
Gravity might get you down.


RE: Jumping to Conclusions
By tng on 9/15/2010 10:10:57 PM , Rating: 2
Yes it is better to get to orbit from the equator. If I remember correctly it has to do with the earths spin and that is one of the reasons that the launch facilities are in Florida. I think that the EU space agency launches are done somewhere in South America for that reason, it takes less energy to launch into orbit there.

Also the suggestion of a Mag Lev system is good. Right now the best example of this is the train from the Shanghai Airport to the downtown area. It reaches about 300mph (not quite sure about the top speed) and they were going to extend it for several hundred miles until the cost of just what they built almost bankrupted them.


RE: Jumping to Conclusions
By marvdmartian on 9/16/2010 9:32:56 AM , Rating: 1
Ah, but if your track is like a loose corkscrew shape, then you can still get the effect of Earth's spin assisting, as well as directing your ship in any direction you want at launch, which might actually assist in putting it into orbit.

I'd keep it down at the South Pole, though, for a number of reasons:
1. "Global Warming" seems to be having a lesser effect in the Antarctic, and the cold air might actually make it easier to cool your superconductive magnetics
2. You're actually building on ice on top of land, instead of on top of water, so it's likely to be more stable (especially if this whole "global warming" thing is true!!)
3. Accidentally hitting a penguin that roams onto the tracks will be much less detrimental to the system than hitting a polar bear. They're having a tough enough time as it is, why give them more to stress about??
4. Less chance that we'll piss off Santa Claus!! ;)


RE: Jumping to Conclusions
By AssBall on 9/17/2010 3:33:02 PM , Rating: 1
No.

The diameter of a spinning object is directly responsible for the centrifugal force. So unless your cork screw is the diameter of the earth....

Also you need extra energy to get something up to speed on a curve, and the track and object take in a lot of extra force stress. Oh, and logistics of setting up an accelerator at the poles is a bitch.


RE: Jumping to Conclusions
By ninjaquick on 9/17/2010 6:41:37 PM , Rating: 2
Unicorns in Narnia are to blame for Centrifugal force, here on earth we are subject to centripetal forces which hold us in a constant loop until we decide exert energy away from the center, spinning does not cause us to go further out. Inside a centrifuge the pressure felt pushing you out is actually a result of your body having a outwards "acceleration (actual constant velocity) that is equal to that of the rotation velocity and radius of the centrifuge with a high angle of exit as your body's inertia makes your frame tend to move in a straight line which is impeded by the wall behind you. This is what helps create a slingshot effect when an object approaches a high center of gravity, enters orbit which decays, increasing forward momentum which ultimately results in a high speed low angle exit.
Thanks to the high rotational radius of Earth at its equator, there is less centripetal force to be contended with which allows for an easier escape from earth's gravity. Dun?


RE: Jumping to Conclusions
By tng on 9/16/2010 11:48:18 AM , Rating: 3
OK found this which explains why it is better to launch from the equator
quote:
equatorial launches give spacecraft an extra 'push' of nearly 500 m/s due to the higher rotation velocity of someone standing on the equator than near the Earth's axis where rotation velocity approaches nil.


RE: Jumping to Conclusions
By Spookster on 9/16/2010 1:29:28 PM , Rating: 2
They can just borrow some inertial dampeners from Stargate command.


RE: Jumping to Conclusions
By johnsonx on 9/16/2010 1:50:32 AM , Rating: 2
I seem to recall an article on DT some months back about a new ramjet/scramjet hybrid engine design that essentially works both ways.


By quiksilvr on 9/15/2010 11:19:40 AM , Rating: 2
We can never control gravity, we will simply find ways around it. Every atom, subatomic particle and quark has a gravitational pull. We have NO idea what it is or why it exists, but it's there.


By AssBall on 9/15/2010 12:03:29 PM , Rating: 2
Thermodynamics notwithstanding? Just turn those off too. Damn things.


By Mitch101 on 9/15/2010 12:47:02 PM , Rating: 5
Couldnt one run around Rosie O'donell and Oprah using the slingshot effect from thier gravity to launch ones self into space?


By Manch on 9/15/2010 4:59:44 PM , Rating: 3
Only by using a klingon Bird of Prey but that would also take you back to the 80's to save the whales.......ughhhh the 80's....

Of course this would be beneficial because you could stop Michael from turning white and then a ghost.....

.....too soon?


By MozeeToby on 9/15/2010 5:08:43 PM , Rating: 2
quote:
Of course this would be beneficial because you could stop Michael from turning white
Little known fact, his autopsy confirmed what he had always claimed; he never bleached his skin, he actually suffered from an extreme form of Vitiligo. http://en.wikipedia.org

Normally the pigment loss is only in patches (I have a few inches around one eye and a few spots on my shins), but in some people it spreads to their whole body. Supposedly it started on his hand, which is why he started wearing the single glove way back in the 80's.


By MozeeToby on 9/15/2010 5:09:52 PM , Rating: 2
Well, that obviously wasn't the link I was going for: http://en.wikipedia.org/wiki/Vitiligo


By Manch on 9/15/2010 5:19:26 PM , Rating: 2
ummmm.....again...space travel, Klingons, rosie, oprah, whales, time travel, 80s.....,Michael, ghosts.


By Fritzr on 9/16/2010 1:12:31 AM , Rating: 2
Space Ghost to the rescue!!!


By AstroGuardian on 9/15/2010 12:19:54 PM , Rating: 2
which is impossible to build :)


By Belard on 9/15/2010 12:26:16 PM , Rating: 2
Just need to have your handy dandy anti-gravity module up and running.

Its very simple, you know.


By tng on 9/15/2010 10:24:10 PM , Rating: 2
Actually no, you can't control gravity, but you can lessen the mass.

There is a well know effect of 2 charged plates set up as a capacitor where it can be measured that the positively charged plate will loose mass as the charge goes higher.

Yes this is possible, but it would take megavolts to get an effect that is helpful in any way. This effect was discovered by two physicists one of whom was an assistant to Einstein researching unified field theories.


By Shadowmaster625 on 9/16/2010 8:52:17 AM , Rating: 1
You mean YOU have no idea what gravity is or why it exists. (You wouldnt happen to be public school educated?) I happen to have a pretty good understanding of at least what it is.

All matter in the universe is actually a conglomeration of standing waves. Every "atom" in the universe outputs a wave. And every atom also receives waves from ALL other atoms. These waves exert a pressure, something like a background radiation. When you place a large mass, like the sun, next to a smaller mass, like the earth, you get a blockage of that background radiation on one side. The sun blocks a small portion of the background radiation, creating a loss of pressure in the direction of the sun. So the earth falls toward the sun. It is very simple once you understand it, no?

It isnt the sun that pulls the earth, it is the sun blocking a small portion of an otherwise constant radiation pressure being exerted on the earth on all sides by the entire universe.


By tng on 9/16/2010 12:01:08 PM , Rating: 3
First time I heard that one.

Really despite what you might think, gravity is really not well understood at all. Ever wonder why we have this stuff called "Dark Matter" out there now when 30 years ago it did not exist? It is because when astronomers finally got the tools to look at the galaxy as a whole they found out that it was rotating to fast for the amount of matter that it has, almost 10 times to fast. Dark Matter is a fudge factor to explain that difference. Maybe we don't know as much as we think we do.


By Shadowmaster625 on 9/16/2010 2:18:51 PM , Rating: 1
That's because they are basing their assumptions on flawed, outdated science. So the complexity increases exponentially as the contradictions keep piling up. That is what always happens. Look how complicated the math became right before the sun was Accepted to be the center of the galaxy. Look how much twisting and form fitting and exception making they had to do to make their theories work... until it all blew up.

Now, mainstream science must accept so many things they are not prepared to accept. The Wave Structure of Matter is one. Radiation Pressure is another. There is also Expansion Tectonics. And SEC Electrolysis. The list goes on and on. Gravity is simple to understand once you realize it is a revoltingly corrupted System that is in fact the source of the confusion. That is the Sole Purpose of mainstream academia - to spread confusion and stand in the way of progress so that those in power cannot so easily be displaced by technological breakthroughs they do not control.


By JediJeb on 9/16/2010 3:20:38 PM , Rating: 2
Do you have references for these theories? I would like to read up on them.


By tng on 9/16/2010 3:35:17 PM , Rating: 2
I was thinking that he was into QM, but I guess not.


By freeagle on 9/18/2010 8:21:28 AM , Rating: 2
It's interesting to think about it this way, though I have one question atm:

How does the mass cause a blockage of the radiation push? Does size of the object also effect it? If yes, how come black holes are such a good blockers, when they are in fact very small.

Is this your own view of the thing or are there any articles to read about it? As someone already posted, it's the first time I hear this as well


Well, let's see...
By chromatix on 9/15/2010 3:24:27 PM , Rating: 4
...clearly it won't be a scramjet at sea level. But NASA generally doesn't suggest doing things that are totally impossible. They're too smart for that.

So, just maybe, they can make an engine that's a normal ramjet at transonic-to-supersonic speeds, and can accelerate the vehicle from launch velocity and sea level to Mach whatever at altitude.

*Then* it can go into scramjet mode, accelerate to some crazy speed, and go ballistic for maximum apogee.

*Then* it brings the on-board mass-driver into play, which imparts even more velocity to the payload. If that's not enough for LEO, add an ordinary boost rocket to that.

The launch vehicle will fall back into the atmosphere. Since it's already at suborbital energy and has wings, recovery and reuse should be feasible.




RE: Well, let's see...
By FormulaRedline on 9/15/2010 3:42:56 PM , Rating: 2
quote:
NASA generally doesn't suggest doing things that are totally impossible.


I'm sure NASA didn't suggest trying to run a scramjet at subsonic speeds. However, the article states the scramjets would activate upon launch; that is clearly not the case. I didn't want people to be misinformed.


RE: Well, let's see...
By Fritzr on 9/15/2010 4:21:14 PM , Rating: 2
True, but 13 to 14 seconds from the time the brakes are released is close enough that most people would consider them lit during the launch :P

Remember that this is a very vague news release, I suspect that the engineers designing the maglev launcher (yes this tech is already used for 200mph+ trains) are aware of the limitations of the SCRAMJet engines.

These spacecraft will be a minimum of 3 stages.
1st stage is the maglev track and that is dropped when they run off the end of the rail.
2nd stage is the SCRAMJet climb to near orbital altitude.
3rd stage will be conventional rocket booster to insert into orbit where additional non-conventional engines do not have to fight gravity.

An alternative 2 stage design has the "launch pad" mounted on an aircraft. Liftoff from 60000-80000 ft altitude is far cheaper in terms of fuel than liftoff from sealevel. Also a conventional airport is used for launch.

The additional feature here is mounting the rocket on a high speed plane that will launch the rocket while climbing at supersonic speed, allowing the rocket to add acceleration to a high base velocity...more fuel saved.

This idea has been kicking around for many years now. I am glad it has gone beyond the "What a great idea" stage into a serious effort to design the hardware that can do it.

Like the SuperSonic Zeppelin, it has been something that could be done if anyone took the time to design the hardware...but the SSZ is still a wacky idea as no one has tried to design one. This NASA design looks like it will fly :D


RE: Well, let's see...
By Manch on 9/15/2010 5:22:58 PM , Rating: 2
what about rail gun technology? Could they use that instead of MagLev or are the similar?


RE: Well, let's see...
By Fritzr on 9/16/2010 1:08:37 AM , Rating: 2
Similar ... both are Maglev linear accelerators,
A Maglev train/sled rides on the outside, the projectile in a railgun rides inside the magnets of the stationary gun. A railgun design gives more repulsion surface for acceleration, but you are restricted to something that will fit the tube. With a maglev the restriction is the max weight that can be accelerated to target speed.


What about bird impacts
By ViroMan on 9/15/2010 3:30:53 PM , Rating: 3
Now that this thing is going to breath air, we need to worry about things that get stuck in its engines during take off. The catapult is going to race in parallel to the land for a bit to build up speed. During this time, how ever long it takes, it will be at risk. Going through a flock at 600+mph is most likely going to cause issues.




RE: What about bird impacts
By JediJeb on 9/16/2010 3:29:07 PM , Rating: 3
Just mount some Ginsu knives on the engine inlets and a basket at the exhaust to catch what comes through and you will have instant BBQ for the astronauts when they arrive at orbit :P


Fireball XL5 !
By BernardP on 9/15/2010 4:57:50 PM , Rating: 2
I must be too old. Surprised that no one has posted this yet:

http://fireballxl5.sfdaydreams.com/

Basically, the same launch system




RE: Fireball XL5 !
By delphinus100 on 9/15/2010 8:57:47 PM , Rating: 2
RE: Fireball XL5 !
By BernardP on 9/16/2010 9:54:00 AM , Rating: 2
Right! Thanks for the link.


Wait...
By cruisin3style on 9/15/2010 1:55:59 PM , Rating: 2
Isn't NASA the only organization to put man on the moon?




RE: Wait...
By mbarry1961 on 9/15/2010 7:07:44 PM , Rating: 3
Yeah, but they used proprietary hardware and closed software so it must have been some dictatorial attempt to manipulate the space market... If only NASA had the PR foresight to name it the iMoon.


I don't know what the big deal is...
By bupkus on 9/15/2010 2:43:38 PM , Rating: 3
...I'm building one now with Legos.

Mom! Where's the jello? My scramjet needs fuel!

Move Mr. Pusspuss! Did you go to MIT like me? No, I didn't think so.




By Belard on 9/15/2010 5:05:17 PM , Rating: 2
Mr. Pusspuss went to Harvard, fool!

A video of Puss Puss on Youtube: Nanna & Lil' Puss Puss in "In A Pinch" or http://www.youtube.com/watch?v=1K_xf378Sos Actual video starts at 1m20s - past the very OLD TV-ADs... which are interesting too.


Alternative Space Thruster
By rbrtw on 9/15/2010 7:39:35 PM , Rating: 2
Catapult, it sounds so medieval. Nowadays, we should have something more elegant and smarter than this.
http://www.youtube.com/watch?v=9ScAHXN_kAY




RE: Alternative Space Thruster
By roadhog1974 on 9/15/2010 8:06:32 PM , Rating: 2
Catapults are inefficient we should use trebuchets.


By Hammer1024 on 9/15/2010 1:46:08 PM , Rating: 3
Ah well... Tis another day and another abridged article...

First up in the batters box: "NASA's sled needs to reach a whopping 600 mph (appr. 1,000 km/h)."

600 mph is 880 ft./sec. or Mach .79 at sea level in a standard atmosphere. In order to start and maintain scram jet (Supersonic Combusting Ram Jet) operation, the thrust chamber fluid (burning air/fuel mix) velocity cannot fall below Mach 1. The typical transition velocity is in the Mach 6 range, so we'd need in the neighborhood of 6699 ft./sec. just to start and maintain the burn. That's 4567 MPH at sea level.

So a scram jet off the deck is not feasible; we'd melt any large cargo capable (human or other) structure created from thermal heating. About the only thing we do have that goes that fast or better at sea level is a thermonuclear reentry vehicle and it doesn't last long enough to matter.

So a combined cycle air breathing engine is a must; an uprated SR-71 type if you will: Turbojet/fan, RAM, then SCRAM.

The turbofan/jet would be good up to about Mach 2 - 2.5, the ram jet then takes over to about Mach 5.5 - 6 which then transitions to scram jet.

Next up: ... The maneuver would be akin to firing a round out of a barrel.

Not a good idea... Not at all. At those speeds, Mach 10 or so, the scram jet vehicle is flying faster than any bullet. The only thing you'd do is fire the bullet and have it come right back through your wind screen... See the example of the A-12; the pre SR-71 interceptor. And the separation dynamics are UGLY!

Forget staging in the atmosphere at those speeds. Either get completely out, then stage so there are no aerodynamic drag issues, or fly the entire vehicle to LEO.

For the LEO option, one would add the closed rocket motor cycle to the engine: Seal off the inlet and push LOX & LHX/Kerosene into the engine. Back to the SR-71 example:
Turbojet/fan, RAM, SCRAM, rocket.

I believe I remember from back in the 70's that the fly to LEO option was the overall best solution for payload to vehicle complexity and throw mass: Lightest vehicle to payload option using an air breathing launch vehicle.

Also, since most active research is into getting a scram jet to burn petroleum (Kerosene) products, it stands to reason the LOX - Kerosene cycle would be the way to go; Kerosene's easy compared to LHX.

The downside of Kerosene is that once on orbit and the fuel cooled, one couldn't restart the engine since the Kerosene would be one big ice block.




Qualification needed?
By futrtrubl on 9/15/2010 12:10:00 PM , Rating: 2
quote:
the first international organization to put a man on the Moon


Let's start with "international". I thought it was pretty definitively national.

And why "first"? Any other organization put a man on the moon while I wasn't looking?




Hold it.
By smartalco on 9/15/2010 1:13:25 PM , Rating: 2
Wait up.

You are telling me that one of the ridiculous pieces of technology in the Ace Combat series, this in particular -> http://acecombat.wikia.com/wiki/Basset_Space_Cente... , is potentially actually going to be built?

I like it.




That scramjet looks familiar
By SnakeBlitzken on 9/16/2010 9:47:07 AM , Rating: 2
Could be the same design Steve Austin crashed before he became bionic?

anyway, the biggest obstacle will be keeping the possums and/or armadillos off the track.




By magnetrain on 9/23/2010 10:26:52 AM , Rating: 2
This launcher concept is a classic and is doable with the technology that we've had for decades. It's called "Ground Assisted Launch," of which there are various types. Thought I'd reference the work that's been done on it.

First, what's been made. Holloman Air Force Base has a sled test facility ("slippers" on steel rails) that's gone over Mach 8, more than enough to launch a vehicle in scram jet mode.

http://www.airforcetimes.com/news/2008/02/ap_airfo...

http://www.youtube.com/watch?v=qdp4gxfwlv0

Then concept work on applying it.

http://www.g2mil.com/skyramp.htm

Although scram jet speeds has been done, you don't need to go that fast to significantly alter launch technology and costs. Because of the nature of ground assisted launch, just getting the vehicle up to mach 1-2 with large vertical component, you can make Single Stage to Orbit work with current tech (6G's.)

It's interesting to note that this technology is vertical vs. horizontal launch agnostic.

Related technology that's in entrepreneurial stage. High G, low cost launch for bulk materials.

http://www.quicklaunchinc.com/

If we ever get serious about space, the technology is already there.




Mass driver
By AnnihilatorX on 9/15/10, Rating: -1
RE: Mass driver
By Belard on 9/15/2010 11:27:57 AM , Rating: 5
Remember, the key is scramjets which uses much less fuel, but only work at high speed. The prototypes needed to be launched by high-speed crafts in order to start the engines.

So, hitting 600+MPH on the ground could be safer than the shuttle/rocket systems we have today if the delivery vehicles are smaller, have less full and complicated systems.


RE: Mass driver
By tallcool1 on 9/15/2010 12:42:21 PM , Rating: 2
Marty McFly and Dr. Emmett Brown used the magical speed of 88 MPH.
http://en.wikipedia.org/wiki/File:Delorean5.jpg


RE: Mass driver
By roadhog1974 on 9/15/2010 7:53:47 PM , Rating: 2
but how will they generate the 1.21 gigawatts?


RE: Mass driver
By Ammohunt on 9/15/2010 1:58:18 PM , Rating: 2
They chew through fuel though the Fuel tanks on this platform would be massive.


RE: Mass driver
By emoser96 on 9/15/2010 8:39:33 PM , Rating: 3
The real problem is the speed of sound is ~760mph at sea level. They're proposing to accelerate the "wedge" to ~600mph and expect scramjets to light? You need to be going around mach 4 to get an effective scramjet startup. Less than Mach 2 and you don't even really want a ramjet. This doesn't even account for the absolutely RIDICULOUS dynamic pressures an air/spacecraft would have to endure traveling > mach 1 (or 3-4 for a low speed scramjet startup) at sea level.

Maybe they'll launch from the himilayas???


RE: Mass driver
By FITCamaro on 9/15/2010 8:50:21 PM , Rating: 3
I hear they plan to use Chuck Norris as a booster.


RE: Mass driver
By emoser96 on 9/15/2010 8:39:34 PM , Rating: 2
The real problem is the speed of sound is ~760mph at sea level. They're proposing to accelerate the "wedge" to ~600mph and expect scramjets to light? You need to be going around mach 4 to get an effective scramjet startup. Less than Mach 2 and you don't even really want a ramjet. This doesn't even account for the absolutely RIDICULOUS dynamic pressures an air/spacecraft would have to endure traveling > mach 1 (or 3-4 for a low speed scramjet startup) at sea level.

Maybe they'll launch from the himilayas???


RE: Mass driver
By roadhog1974 on 9/15/2010 9:37:57 PM , Rating: 2
Launching from tibet certainly makes technical sense.

Can't see it happening.

most countries want to launch locally given the military
implications.


RE: Mass driver
By guacamojo on 9/15/2010 11:33:06 AM , Rating: 5
The mass driver is there just to get up to the minimum operating speed for the scramjet. By itself, it doesn't save much fuel.

The scramjet stage does most of the work of accelerating to escape velocity. Since it's an air-breathing engine, you don't need to carry oxidizer, just fuel. That dramatically cuts down on launch weight.

Then the spacecraft itself is kicked into orbit by pushing away the scramjet stage (which is itself reusable, I assume) or by chemical rocket.

It's an interesting concept.


RE: Mass driver
By AstroGuardian on 9/15/10, Rating: 0
RE: Mass driver
By ekv on 9/15/2010 12:46:30 PM , Rating: 2
quote:
The mass driver is
... the fuel you don't have to carry.

Yes, interesting. But, dare I ask, what about the birds?


RE: Mass driver
By Mitch101 on 9/15/2010 12:49:12 PM , Rating: 3
Fabio is working on that.


RE: Mass driver
By Hafgrim on 9/15/2010 6:28:24 PM , Rating: 2
High energy microwave antennas on either side of the tracks that focus down the line ahead of the launch vehicle should easily do the trick of keeping the launch vehicles safe from any birds & in dramatic fashion I might add. =)


RE: Mass driver
By DanNeely on 9/15/2010 10:03:31 PM , Rating: 4
Yup. The scramjet will save a lot of fuel. It's the only realistic near future technology that can significantly reduce the cost of launching something into orbit.

Doing a back of the envelope calculation, a 1000m/s launch track + mach 10 scramjet will reduce the amount of fuel needed to reach mach10 by a factor of 2.2 allowing for either a much smaller total rocket or a much larger upper stage + payload combination. At mach 25 (slightly under orbital velocity of mach28.5) the ratio increases to 6.5:1. At mach 28.5 the ratio goes up to 8.3:1 but this would be undercut somewhat due to the need for a circularizing rocket burn once the ship reached space (otherwise it's in a ballistic missile type orbit and would reenter shortly after leaving the atmosphere).

As back of the envelope math these calculations ignore various fiddly bits that can significantly alter the final results. The relative mass of the ramjet vs conventional rocket module would be a major factor in where the actual numbers end up. For a real world example a large chunk of the higher performance of hydrogen rockets over kerosene or solid fuel rockets is lost because cryogenic hydrogen is bulky and the larger fuel tanks increase the parasitic mass of the rocket itself.

For anyone curious about my math, the rocket equation when solved for the mass ratio is:

m0/m1 = e^(deltav/g/Isp)

e = 2.71
g = 9.81m/s
Isp (kerosene rocket) = 350s
Isp (kerosene ramjet) = 1250s

deltaV (kerosene rocket) is 3400, 8500, or 9700m/s in the three cases above.

deltaV (kerosene ramjet) is 2400, 7500, or 8700m/s (remember the ramjet is leaving the launch track at 1000m/s).

Specific impulse (Isp) is a measure of how long 1kg of propellant can produce a thrust of 1g. Since only ~28.1% of the propellant in a kerosene rocket is kerosene (the remainder is oxygen) a ramjet, by getting its oxygen from the air, will have 3.56 as much kerosene per kg of propelant and be able to burn for 3.56x as long giving an Isp of 350*3.56 ~= 1250s.

PLugging the numbers above into the rocket equations gets mass ratios of 1.22, 1.84, and 2.03 for the scramjet vs 2.69, 11.88, and 16.86 for the conventional rocket. These numbers divided by each other are what I cited in the 2nd paragraph.

http://en.wikipedia.org/wiki/Tsiolkovsky_rocket_eq...
http://en.wikipedia.org/wiki/RP-1


RE: Mass driver
By AssBall on 9/15/2010 11:37:13 AM , Rating: 2
That 10 seconds of fuel is probably about 20 times less total volume though. The scramjet has very efficient fuel/thrust/aerodynamic lift ratio, and a new lightweight vehicle will not be trying to drive 4,250,000 lbs directly perpendicular to gravity (rough shuttle weight @ liftoff).


RE: Mass driver
By theArchMichael on 9/15/2010 1:23:22 PM , Rating: 2
True, plus You wouldn't need the disposable dildo shaped fuel tanks to help penetrate the atmosphere.


RE: Mass driver
By MozeeToby on 9/15/2010 11:40:58 AM , Rating: 2
I think the idea is that the cannon launch gets them up to a speed that a SCRAM jet can work. SCRAM jets are nice because unlike rockets they are air breathing, they need to take fuel up but not an oxidizer to burn it with.

There are a lot of downsides, only some of which are addressed by a mass driver launch. First is that they can only work at extremely high speeds, you need to boost them up to those speeds using some other engine technology. Second is that no one has ever flown one anywhere close to orbital speed (Mach 25 about). Finally, even if you can reach orbital speed you still need a relatively small rocket to actually insert yourself into orbit, since the SCRAM jet uses air as its oxidizer you can't use it at orbital altitudes.


RE: Mass driver
By sealsix6 on 9/17/2010 8:37:40 AM , Rating: 2
I remember this launch idea(rail acceleration) was kicked around on Popular Mechanics in the 90's. They went for the maglev variant on a mountain slope.

I think the research pointed to massive cost prohibitors and it was canned.

Maybe now they can make it work. Maglev plus vacuum tube/tunnel to an altitude of maybe 4000m.


RE: Mass driver
By SimBoB on 9/15/2010 12:26:42 PM , Rating: 2
The Fabio pic is rather appropriate- Just because it's technically possible for a passenger vehicle to be accelerated to 600mph and then "flung off" at the end of the track (along with a fueled launch vehicle to make up the other 15,000mph) doesn't mean it's the best way to fly.

Nevertheless, sled launch has been studied for nearly 40 years- here's a partial list:
http://www.astronautix.com/fam/slenched.htm

And some video of an actual sled launch:
http://www.youtube.com/watch?v=sBZN3c7O9wc&feature...

B)


RE: Mass driver
By theArchMichael on 9/16/2010 9:09:34 AM , Rating: 2
Ok, I give up... what does fabio have to do with reusable space vehicles???


RE: Mass driver
By SimBoB on 9/16/2010 1:22:35 PM , Rating: 2
"Game reviewers fought each other to write the most glowing coverage possible for the powerhouse Sony, MS systems. Reviewers flipped coins to see who would review the Nintendo Wii. The losers got stuck with the job." -- Andy Marken














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