Successful First Launch of Aerospike Engine

ScottKin writes "CSULB announced that on September 21st they achieved a milestone in aerospace engineering when they successfully launched their 'Prospector 2' rocket powered by an 'Aerospike' engine. What makes this remarkable is that even NASA had trouble with testing their incarnation of an Aerospike engine - but the Linear Aerospike Engine is quite a different beast. More info on this definitely-newsworthy even can be found at the California Space Authority website."

I ask everybody ...

... out of respect for the family of the just deceased web-server, no slashdotting jokes please.

For the lbf impaired

The sea level thrust of this engince (204,420 lbf) is equivalent to 900,404 Newtons.

In comparison, the Space Shuttle engines produce 2,174,286 Newtons at sea level.

What did they do different?

It isn't clear what they did differently from the others who have tried this. Yes, I understand theirs is not a linear engine like Lockheed's. But I doubt the older versions that are discussed in the article were linear. Is there something else that is different? New materials? Some other breakthrough?

Redefined success

As said in their site the goal was to get off the pad. Anything puffing hot gases generally downwards while being guided by quite a long launch rail achieves that, including 'several' seconds of stable flight. Engineers in the 60s could have done the same easily but they knew the result without even trying and their goal was in the orbit, not one foot above the pad.

Real innovation in this engine is the use of ablative shielding inside the chamber. But that makes it even harder to overcome the original problem of this type of engine; having steady and stable burn/gas flow (ie. equal thrust) around the annulus. Linear aerospike engine does this by replacing one large chamber with numerous small ones which are easier to control.

Nice diagram

here [nasa.gov] ;)

Aerospike introduction

If you're not a rocket scientist, here's a very readable introduction to aerospike engines [aerospaceweb.org].

Caution: It is rocket science, and a little bit of maths is required to appreciate even this introduction.

story from CSULB with a little more detail

http://www.csulb.edu/colleges/coe/ae/rockets/aeros pike/ft-1/flight-1.htm [csulb.edu]

Successful?

After a smooth countdown and nominal engine ignition, the thirteen-foot long P-2 quickly accelerated up a 60-ft launch rail and entered stable flight. Several seconds later it abruptly pitched ninety degrees and demonstrated unstable operation until finally transitioning into a ballistic terminal descent. The subsequent impact with the desert floor destroyed student payloads provided by a USC/JPL team and another from Cerritos High School, but the aft section with the aerospike survived relatively intact. Preliminary analysis indicates that the most probable cause for the observed flight behavior is that part of the engine's graphite exit outer ring experienced excessive and asymmetric erosion, which in turn created a side thrust component.

I guess that's a form of success. But there's probably a reason why everyone else is still doing ground tests.

Sounds like

Sounds like though the engine worked as planned, everything else that had anything to do with the rocket, it's payload, camera, and rescue chute were fucked...

And in other news...

... we hear that Nigeria has blasted a satellite into orbit [google.com]. No comments have been made about a purported increased need for broadband satellite internet access...

Space development by students

Great.
Though the benefit of a aerospike nozzle is effective only in a flight through which the back pressure varies (i.e. sealevel to very high, like SSTO), at now, the aerospike-nozzle-powered flight itself is important.

Besides, this rocket was made by students. What kind of other space engine development are there in the world?

Sadly

The article has more spin than a British Government press release.

The motor worked except that, well actually it went badly wrong very soon after launch. Combustion gases went the wrong way and caused the engine to malfunction.
Result: crash. Destruction of payload.

I guess the definition of success came from the people who defined "interception" of Scuds by Patriots in Gulf war 1 as meaning more or less that both missiles were in the air at the same time.

Meanwhile, relatively primitive Russian rockets continue very reliable and Ariane just put up another two comms satellites last night, plus the European moon mission which is aiming for some sort of record as the slowest trip to the Moon ever. Far from being an endorsement of private research versus NASA, it suggests that caution and extensive testing remains the norm in anything to do with rocketry. Even if the next flight is successful, I guess a huge amount of further work would be needed before anyone would risk a real commercial payload on a rocket using this nozzle technology.

Hurrah

At last, we're one step closer to the X302. Now, if only we can get the Goa'uld hyperdrive to work, we're in business.

Finally

I was wondering how long before a Spike plug engine would fly.

Altho it terminated after a couple hundred feet, we know one thing. It can lift off. The hardest part of any flight.

All you nay-sayers, go fly a god damn kite.

This isn't an aerospike nozzle, it's a plug nozzle

A plug nozzle is a tapering nozzle; ideally tapering down to infinity, you always chop it off short for obvious reasons.

An aerospike nozzle is a plug nozzle but it gets its name because you're supposed to inject gas in the base to provide extra pressure - that gas is the 'air' spike. And the main advantages come about because you dynamically adjust the pressure of the base dependent on the vehicle speed to optimise the shape of the aerospike and give maximum possible thrust. (Basically the air spike pushes on the exhaust gases which in turn push on the ambient air, the result is that the nozzle can compensate for the atmospheric pressure changes over the flight envelope better than a conventional 'bell nozzle').

Now this nozzle had no base gas injection, so is in fact just a plug nozzle. Plug nozzles aren't bad, but aren't necessarily anything like as good as an aerospike.

Trouble testing aerospike?

What makes this remarkable is that even NASA had trouble with testing their incarnation of an Aerospike engine...

Can you back that up? From what I read, the aerospike tests went fine. A friend, one of the Shuttle engine designers and who was in contact with the linear aerospike group at Rocketdyne, said he heard that the aerospike delivered the expected thrust during its ground tests. So what troubles are you referring to?

I often wondered if NASA didn't screw up cancelling the X-33. The only major failure that I know of in that project was the fuel tank and given that it was the one of the only two they ever made, it seemed like giving up cooking because your first few tries end up tasting lousy. When the X-33 tried to recover from the tank failure by testing the craft with temporary aluminum replacement tanks, NASA pulled the plug because the extra weight of the temporary tanks would compromise the test rocket's performance. Seemed short sighted at the time and I've never seen anything since that indicated it was the right thing to do.

Mirror?

This has some of the exact same quotes from above so it might be a mirror. [spacedaily.com]

kinda off topic

but i find space an amazing field of study what would i have to do to get a job writing code for nasa or another space authority and what systems would i have to study i know nasa runs on solaris and other unix. thanks

the moon! alice the the moon!

we should actually forget mars for now develop a space station on the moon use that for our launches cuz the gravity is less we'll need less power aka less money to launch from there and it'll give us a bigger place to perform experiments*the moon that is* forget these orbiting space stations they are stupid the moon owns.

It WAS a failure with the engine

From the site [csulb.edu] provided in another link:

The graphite outer ring (blue) was not perfectly sealed with the bottom of the chamber (grey) and moved downward very slightly. This opened several gas paths between the ring and the ablative material (beige) which then melted the back of the chamber and led to thrust vectoring. This phenomenon did not occur during the static fire test.

So it looks like the test did ultimately fail due to a problem with the engine. Nevertheless, the rocket did fly.

__

Why yes, I AM a rocket scientist.

Gotta love the spin...

Even though the motor failed in flight, this was still a 'successful' test that 'met its objectives". In the process of destroying the vehicle, the flight demonstrated nothing not already demonstrated on the test stand.

These guys have been learning PR from NASA and Microsoft.

Re:Research is good...

Considering that the space elevator is just very slightly beyond the pipe dream stage, yes.

You won't see the end of rocket delivered sattelites for some years to come. I'm sure companies aren't putting their sattelites on hold, only beacause there might be a space elevator some day.

Re:Research is good...

And how do you get the tousands of tons of material to construct the space elevator in orbit?

Re:Huzzah for Free Enterprise

It doesn't help much that NASA keeps getting its funding cut every year. The reason we end up only sending space probes is because its all we can afford to send. Private companies have the money and ability to explore because visionaries see profit in the long term. If we went nuts and actually gave NASA the funding they needed I bet we could get a man on mars within 20 years, its just that the politicians see no reason to perform long term budgeting when there's more than enough porkbarrel projects just itching for them to sign so that they can stay in office and sign more porkbarrel projects. Doesn't help that the public generally doesn't give a crap about space exploration anymore either.

Re:Research is good...

I believe that most people have stopped laughing at the idea, which means it will be built in about 50 years, if Clarke is ot be believed.

No.

No. Not in my opinion.

1) The fail scenarios of space elevators are not very good. Think about the possible fail scenarios from the various areas: political, military, natural disaster, engineering. Consider the impacts and probabilities.

2) Space elevators only get you up to geostationary (and maybe 2X), they don't get you much further than that.

3) From the perspective of the Solar System, they are a very expensive form of navel gazing.

From a longer term perspective it is better to spend the resources on finding cheaper ways to get to geostationary and to other planets. And maybe even other systems.

Once we reach the technological level to do all that cheaply, THEN we can consider building the space elevator - because it'll be a piece of cake by then. Have all the tech to make it viable.

Just because you think you've figured out how to make the concrete doesn't mean you should start building a skyscraper. Don't try to build skyscrapers before you develop cranes and the rest of the tech and systems.

Re:on this date in history

So, what's your point?

Not just bureaucracy

Bureaucracy is not the only problem. Private organisations can be bureaucratic, too. The real problem seems to me to be one of perverse incentives.

1) NASA appears to lack a intentional mission. It's de-facto publically assumed mission is something along lines of "do space stuff". But it has few real "space stuff" goals, because it has no (profit) incentive to go there. Shuttle "science experiments" are ludicrous. The ISS does nothing and goes nowhere, expensively.

In reality, as evidenced by all the politicians' attitudes to NASA (even during their condolence speeches), its real mission is: national self-congratulation, international self-promotion, congressional pork, and a vague continuance of the "sense of progress" of the moon landing years.

Naturally the above is not conducive to good "space stuff".

2) NASA is funded, not invested in. Their budget isn't going away (unless, perversely, they demonstrate they can do more with less, which would lead to them being de-funded). The source of their money is politicians, not commercial profits. Actual success brings them no payback, and failure does them no harm. The incentives this gives are: pocket the budget, don't waste it on any actual space stuff, and beg continually for more funding.

3) For this funding, they are expcted to produce immediate bigness, not gradual affordable advancement. Thus their attitude to problem solution consists of "throwing money at it".

A good analogy here is the architechtural construction techniques of the Egyptian pharaohs. You can build quite big pyramids if you throw a fortune and an army of slaves at the job. But it doesn't scale, it doesn't advance the state of the art, and, crucially, it doesn't get any cheaper when you do it more often. It was the brick-and-mortar commercial construction industry that led via engineering advances to modern skyscraper construction.

When NASA complains of underfunding, it's analogous to the pharaonic architects complaining that their skyscraper plans are hobbled by the shortage of slaves.

Re:on this date in history

I'm sorry, but StarFleet's Ex Planitia Shipyards orbiting Mars are not quite complete yet - we're waiting for the Systems Development group to finalize their design for the Matter/Antimatter Containment System, Mark 6 Computer Systems, Anti-matter injectors, Warp Drive, Transporters and the other cool technologies that will remove the need for old-fashioned chemical-based combusion systems.

If you can wait until the 24th Century, I think we'll have things pretty well nailed-down. In order to wait until that time, have you considered Cryogenic Storage of your body?