Armadillo Flies... Briefly

david.given writes "Armadillo Aerospace did their first untethered test flight last week, at the Oklahoma Spaceport, using their new tube-shaped rocket. Predicted height was fifteen hundred feet; unfortunately a computer failure caused the vehicle to tip over and dive into the ground from a hundred feet up, causing severe damage (i.e., it requires a rebuild, not a repair). See the report and the slightly depressing video footage."

Comments

Ouch!

[Raetsel]

Boy, that "from the lawn-dart dept." crack is painfully accurate. I just got the video (at ~12K/s), and that thing came almost straight down! (Yes, there was much tumbling involved, but at impact it was pointed pretty much 180 from the way it started.)

Also, if you look close, you'll see metal (?) plates flapping on the ground at launch. (Looks like a folding launch pad.) Did they interfere with the rocket and throw its' stabilization routines off? Who knows.

Stuff likes this happens

[Anonymous Coward]

As an experimental physcist in aerospace, I've got to say that this looks real familiar. A cable that comes off in flight? Sounds just like my latest balloon flight that lasted 5 minutes after launch before a power supply failed.

The reality is that with a complicated system, there is a lot that can go wrong. 99.99% reliability on a system with 100,000 connections still means that 10 connections break in flight. This flight was unlucky in that the connection that broke was the main power cable. Next time, they'll have the watchdog on board, killing the engines when the power dies.

Good luck guys, I know how it feels. Experience is a hard teacher, but it's sometimes the only ones.

P.S.: the "Crossbow" the post talks about is an inertial guidance device. I've used those before (the cheapies, not an expensive one like this).

Keep trying...

[Goonie]

On the off chance the Armadillo guys read this post, I'd just like to congratulate them for making it as far as they have, and hope that they aren't too discouraged by the less-than-perfect result of this test. If you expect things to work perfectly every time, you'll never try anything new.

Good luck, and count me in for a ticket when the bugs are out of the system!

Re:Shareaza The Video

[Baldrson]

This link may do a G2. The URL was created by the G2-enabled Shareaza.

Not true at all

[Anonymous Coward]

Pressure fed rockets can achieve significant altitudes, just look at the Scorpius and Beal efforts. France developed and launched a pressure fed orbital launcher years ago. No turbopumps are required at all.

Even if pumps are decided to be used, there are a couple low-tech alternatives to turbopumps that have been demonstrated in the past ten years, the ASTRID piston pump and the Flowmetrics Pistonless Pump come immediately to mind.

There's also the gas generator to be considered, basically pressurizing the propellants with a specially designed slow-burning solid rocket motor or a slow peroxide feed on a catalyst pack connected to the main propellant tanks.

Turbopumps are old tech!

Re:Stuff like this shouldn't happen

[Once&FutureRocketman]

As far as I can tell from reading the report and looking at the video, this crash was not due to a computer failure.

It was due to a design failure.

The rocket appears to be unstable, which is to say that the center of gravity is behind the center of pressure. Looking at the pictures, it's not too surprising. The vehicle is too short vs. it's diameter, and the flared base isn't big enough to stabilize it (i.e. not big enough to push the Cp back behind the Cg of the vehicle).

I imagine that Carmack etc. knew that it was aerodynamically unstable and counted on active feedback controls to compensate, which was their primary mistake. By doing so, they greatly increased the critical complexity of the system, which is to say they increased the number of things that would kill the vehicle if any one of them failed.

It would have been far better to design for simplicity and graceful failure by building a vehicle that is aerodynamically stable. Someone forgot KISS.

I guess I shouldn't be surprised -- this is what happens when you let programmers design rockets. :)

Uhh.. no

[malakai]

Soldering a wire directly to the battery terminal is not a "Good Thing". When the solder hardens, it creates a point between the hardened solder soaked wire and the solder free wire. This, under vibration/stress leads to a clean fracture/break.

Mill specs require you _not_ to solder directly to this type of connection. Instead double crimp (but don't over crimp) the wire to a mechanically fastened connector.

so anyhow mister smarty pants, your dry humor was inaccurate and thereby makes me laugh at you, and not with you.

-malakai