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."

Comments

I ask everybody ...

[Aceticon]

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

For the lbf impaired

[CausticWindow]

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.

Re:For the lbf impaired

[VCAGuy]

Damn, that's impressive. The GE90-115B (exclusive to the Boeing 777) is currently the world's most powerful turbofan engine and is capable of producing "only" 127,000 lbf (which shattered aviation records the world over for turbofan engines). When you consider that the GE90 is 11.25 ft in diameter (without cowling) and 23.9 ft long (again, without cowling) and NASA's/Boeing's aerospike engine is measured in inches, that's like...damn.

Re:For the lbf impaired

[blufive]

So, what article are you reading?

The 204,420lbf you're quoting is for the Boeing XRS2200 Hydrogen-Oxygen linear aerospike, proposed for the X-33, which never got off the ground.

The little dinky engine powering the rocket mentioned in the article produces 1,000lbf and runs on Ethanol-Oxygen.

Nice diagram

[Sir Haxalot]

here ;)

Re:Research is good...

[CausticWindow]

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.

Aerospike introduction

[David Kennedy]

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

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

[caillon]

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

Successful?

[Fzz]

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.

Re:Successful?

[Lord_Dweomer]

"The subsequent impact with the desert floor destroyed student payloads provided by a USC/JPL team and another from Cerritos High School"

Jesus, they were carrying students on this thing?!?!?!

Re:Huzzah for Free Enterprise

[Volmarias]

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.

lbf? Newtons? What about Elephants?

[SkiifGeek]

What's the idea with all this lbf and Newton units of measurement?

This is Slashdot for fsck's sake, let's hear about it in terms of elephants, swallows carrying coconuts, the size of San Francisco or SCO licences.

The rationality that is creeping into Slashdot is disturbing.

Sadly

[panurge]

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.

Re:Sadly

[gilroy]

The launch was successful. The landing, however, needs some work... :)

thanks! did you see the foot?

[twitter]

Wow, a thing about half the size of a man's foot generates 1/20 the thrust of a space shuttle engine. In English units, 1/2 foot is kicking ass.

If you are not a rocket scientist, that translates to much zoom per pound mass.

Does the "California Space Authority" bother anyone else besides me? What's next, Arnold calling himself "big chief" of independent California and wearing feathers on his head?

Re:thanks! did you see the foot?

[tektrix]

Uh . . . I think you're a bit confused here. The aerospike engine tested with the rocked develops 1000 lbf or 1356 Newtons/M, and the shuttle generates 2,174,286. That's 1/1603 the size of the shuttle. I think you were looking at the stats provided for the Boeing angine. All that said, the test vehicle could easily lift several 10's of gerbils. I imagine that the gerbils would hate the part about "transitioning into a ballistic terminal descent"

Hurrah

[FifthElephant]

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.

Redefined success

[Tap-Sa]

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.

Not a big deal

[twiddlingbits]

It's great for some college kids, but it's not bleeding edge like some think. Lots of spin,not many facts (but hey, thats why the marketing guys make the big bucks and we get to try to make what they say work!)

Linear aerospike rocket engines have been around for more than 30 years. They were created by Air Forc in the early 1960s, Rocketdyne developed the technology for both linear and annular aerospike engines during the mid-1960s, ground testing various designs into the 1970s.Aerospike engines were proposed for use on the Space Shuttle, but the engine was turned down because the technology was considered too immature at the time. Since then, Rocketdyne has accomplished 73 laboratory and ground-test firings, with over 4,000 seconds of operation of this type engine. (the kids flew for FOUR seconds, 3 orders of magnitude LESS)

The RS-68 Rocketdyne aerospike LIQUID Fueled engine was planned for the X-33 SSTO (cancelled) but linear aerospike engines of up to 430,000 lbs thrust (XRS22200) have been sucessfully tested.

In other words who ever wrote the press release for the University didn't do the research. The kids are back when the Nazi's were in the 1940s.

Re:Political problem, I would guess.

[AJWM]

As noted, linear aerospikes work (at least in ground tests). The problem with X-33 (well, one of) is the general shape that invited the use of a linear (vs round) aerospike in the first place.

That deltoid shape (coupled with the central cargo bay, etc) pushed them to a V- or Y-shaped fuel tank, on which they were pushing material limits. Basically they couldn't make a pressurized, lightweight tank that shape that was also leakproof. (The original 70s StarClipper design that the X-33 was loosely based on used two external tanks joined in a V configuration around the lifting body.)

X-33 had other problems, of course. The whole vertical takeoff, horizontal landing profile is a mistake -- it means you need to engineer the vehicle for two orthogonal primary load paths, and it makes an intact launch abort virtually impossible (vs say VTVL). That latter in turn means you have more failure modes and have to engineer in more redundancy, do more intensive between-flight overhauls and inspections, and that generally you've just reinvented everything wrong with the current Shuttle system.