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

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.

Re:Aerospike introduction

[Anonymous Coward]

I was a rocket scientist - actually designed things used on the space shuttle fleet and studied Aerospace Engineering at a top 5 school. The equations for these sort of engines are some of the easier to understand and use in this field.

The propulson class I took used a book from 1965 and covered every theory I've seen put in practice since 1980. Profound improvements have been made due to improvement in materials, but the basic theories haven't changed.

story from CSULB with a little more detail

[caillon]

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

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?

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

[WolfWithoutAClause]

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.

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.