Official Armadillo Q&A thread

Hello Fatron,

James Bauer posted some pics on Flikr of the cockpit. There is no passenger seat. It looks like a control consol of some sort, presumably for the engine, is sitting in the place the right hand seat usually is. This aircraft is normally a four passenger job, but the back seats are filled with one of the tanks. I think someone said it was the LOX tank in a previous post.

Matthew,

I just looked at the link you provided of the AA powered takeoff. That was too cool. You need a bigger airframe. Pixel fuel stores would be very handy.

Previous articles have stated that thrust decreases as fuel burns. Does this have to do with pressure? Is there no way to regulate pressure to maintain a constant value during the entire burn? Perhaps you've already explained this and I just missed it. Was it covered on the AA website?

I just saw this hit the wires:
http://www.webwire.com/ViewPressRel.asp?aId=73503

Were the mystery teams present for this conference? Are you under a NDA regarding their names?

As the propellant is depleted and the empty tank volume (ullage) increases, the pressure decreases, and yes, that decreases performance. It's possible to have an external high-pressure tank that supplies regulated pressure to the propellants, but that's a separate system which adds more complexity and requires space for an additional tank. It's not out of the question, though. Then there is the idea of using pumps to supply constant pressure, which is XCOR's approach, but we aren't fans of pump systems.

I don't believe they were there, but I didn't go so I'm not positive. I'd have to confirm with Neil (he has talked about the status of the other teams there, but they were already-announced teams).

From the article on CNET: "The league is building five rockets so that it will have six by next spring."

Armadillo, it looks like you have plenty of work in store for you over the next nine months. With 5 more rocket engines to build and 10 tanks.

With the new FAA permit requirments for tethered testing, and the work you are doing for the RRL and NASA, it doesn't seem like you will have enough time to do extensive hover testing with the new engines on MOD and Pixel in time for the LLC. Hopefully you will though, because I want to see AA win the LLC prize this year.

You guys should win the LLC this year because along with the reliability of the new engines, the third time is a charm!

BTW, what is the current count on your TTIAC (third time is a charm) counter?

Hehe, I've suggested wagering on the total number, but it will probably be hard to keep track!

Is there any issue with CG shift during flight phase. If so, how is it compensated for?

Over at hobbyspace, it looks like John has responded to a post saying they have now completed 7 test flights.

http://hobbyspace.com/nucleus/?itemid=8112

Maybe this is a dumb question, but I just thought of it after watching the test flight video, traditionally the fuel tanks on the modules and previous vehicles are always oriented more or less straight up, so isn't there just a fuel pickup at the bottom of the tank since it's pressure fed. When it's in the plane how does it always pickup fuel when it could potentially be upside down?

They're using stainless hoses as flexible propellant pickups. If the fuel line accidentally picks up gas the liquid sensor triggers an engine shutdown, on the LOX side that might be a bit different.
Being upside down isn't a significant problem, but it might still be possible to have the fuel and hose part company.

Very cool. Would love to see it in person. Will it be flying in North Texas anytime soon?

http://media.armadilloaerospace.com/200 ... akeoff.wmv
http://media.armadilloaerospace.com/200 ... akeoff.wmv

Climb, baby, climb!

Those videos of the test flight were extremely impressive. Any details about test flight 4? Was that a full propellant load burnout? How high did it get? What was the climb rate? Was that the angle of attack necessary to keep the plane at max V under full power?

Extremely impressive. Sounds and looks wicked, to boot. Good job, guys!

The altimeter went around 6.25 times, so I think that is 6250 feet (engine cutoff was at 6000). Time from liftoff to engine cutoff was 56 seconds.

John's hoping to set the time-to-climb world record of 3000 meters in 26 seconds. I wonder if that video was at full throttle. My guess would be not since the takeoff roll seemed a little longer than some of the other videos. I wonder if they'll be able to do it with this plane/engine configuration.

Russell has more videos of the test flights up:


http://www.flickr.com/photos/27997120@N05/

I did manage to snap a few pics, and put them up on flicker also...

http://www.flickr.com/photos/29153024@N07/

Just shots from takeoff. Will see what else I can get soon...

I just posted a new, long update that covers the first flight testing of the Rocket Racing League plane: http://www.armadilloaerospace.com/n.x/A ... ews_id=361