Innovations in Space Launch Systems

WolfWithoutAClause writes "Its long been a dream of people to just fly into space in an airbreathing aeroplane, however this has sadly remained as science fiction. The main problems have been a) collecting air at mach 23 requires that most expensive material: 'unobtainium' ; and b) having to carry extra airbreathing equipment into orbit. New Scientist has an article on a new study that NASA is funding to investigate whether an airbreathing launch vehicle might in fact be possible."

Comments

Some more Info

[jonfromspace]

There has been extensive research on this:

Including, but not limited too:

1)This Article in Scientific American
2)This Reasearch Paper
3)This NASA report


Just FYI ;-)

Hard to See

[SatelliteBoy]

The last paragraph says a lot about this concept. They may end up with a net energy loss.

The problem with Horizontal Takeoff, Horizontal Launch designs is resident time in air. Most boosters launch on a pretty vertical trajectory to get above the energy-robbing atmosphere. They do pitch over in the air, but only to use gravity to do most of the work for them. Boosters even launch up, reach a local maximum altitude, then decend under power in order to obtain the very large velocity required for orbit. Getting this velocity in air gives a lot up to drag.

This idea gets around the mass penalty for heavy landing gear by gaining weight in the air. Aircraft landing gear accounts for about 3% of the maximum total takeoff mass. This is for sufficient strength in a takeoff abort situation.

Pretty clever, but I think complicated machinery that requires extensive maintainance won't get us into space cheaply. The price of space travel is largely the cost of people on the ground. It takes about 10,000 people to service the Space Shuttle, hence its cost. LOX is cheap, and so is LH2.

It will be interesting technology, but I disbelieve that it will lower the cost. To get into space cheaply, I think we need to do two things:

1.) build it big.
2.) build it simple.

After all, NASA spent thousands to get an ink pen to write in space. The Russians used a pencil...

SatelliteBoy

Re:Hard to See

[Leon Trotski]

After all, NASA spent thousands to get an ink pen to write in space. The Russians used a pencil...

Spider Robinson writes a column, Past Imperfect, Future Tense, for the Toronto Globe and Mail. Some time ago, his column was titled "Senator Socksdryer and the Two Million Dollar Boondoggle". In it, Spider relates a conversation he had with Buzz Aldrin at a science fiction convention where they were co-Guests Of Honour. Buzz Aldrin related a fairly hushed up incident in the Apollo 11 mission.

The lunar landing module was very tight for space. The story is that, at the end of the exploration phase of the mission, as our heroes get ready to return to Earth, they need to remove their backpacks (dead weight) and switch back to the LEM air supply. In removing his backpack in the tight constraints of the LEM, Neil Armstrong breaks the ignition switch for the ascent engine. They are stranded on the moon with no tools to fix the problem and a finite reserve of air.

As Spider puts it:
``It dawns on Armstrong and Aldrin that they are now dead men walking, a long way from home.

``And then, God be thanked, Armstrong remembers what Senator Jocksfire called the Two Million Dollar Boondoggle. That egregious taxpayer-ripoff frippery: his zero-gravity pen. He retrieves it, roots around in the ruins of the switch...and becomes the first man ever to hot-wire a vehicle on another planet."

In the rest of his article, Spider uses the space pen, and other by-products of space-race research, to justify the support of basic research by government in the face of opposition from pork-barrelling politicians like Senator Socksdryer.

The space pen had a bigger side effect than having any notes written by American astronauts more easily preserved for posterity. The failure of Apollo 11 could have crippled the American space program and provided the Russians with breathing room for their moon landing efforts. Kennedy's goal, after all, was ``to land a man on the moon and return him safely"

Jerry Pournelle argues the point that the fall of the Soviet Union is in large part due to the fact that the Russians bankrupted themselves trying to match the American SDI ("Star Wars") effort. Their belief that the Americans might succeed at Star Wars was, Pournelle believes, founded in the USA's success on seemingly impossible projects like Apollo. Would we still be living with the Cold War had we not had the space pen?

Yawn. Take a look at the "Black Horse"

[McSpew]

Seriously, a former USAF captain proposed a hybrid air-breathing vehicle which would be fueled with LOX once in the air by a modified KC-135 at least 7 years ago.

The guy who came up with the idea has since left the USAF and founded a company solely for the purpose of commercializing the concept.

The primary difference between the Black Horse concept and the one proposed in this article is that it wouldn't take three hours for a Black Horse-type aircraft to collect the LOX necessary to fire its rocket motor(s). They'd take on the LOX from the KC-135 while airborne in presumably less than three hours.