Armadillo Test Flies New Vehicle (w/video)

[josh_simonson]

Stable feedback systems can be complex to design, specifically the gain at the frequency that corresponds to the loop delay time must be less than 1 or you get positive feedback that causes oscillations or sloppy settling.  When dealing with instability this leaves 3 options, increase frequency compensation of the amplifier so the gain rolls off at a lower frequency, decrease the DC gain to reduce the gain over the entire frequency spectrum, or get a faster attitude sensor to push the phase inversion out.

Generally killing DC gain is the easiest of the bunch, but it comes at the cost of accuracy - which is often a firm design requirement.  Generally I start a design by pegging the gain at the lowest point that will safely meet my requirements, then fiddle with compensation if needed and last consider architectural changes if compensation is intractable or prohibitive.

From the sounds of it they're either reducing their DC gain or fiddling with some AC gain parameters in digital filters that are used to compensate the system.

[meiza]

astrobrian - 5/9/2006  8:37 PM

The daylight test shown above was also cut short by something said to be GPS in the video.

It tells all in the update: it was raining, and they couldn't get good enough GPS data (I gather the two things were related).
They might relax the terms a bit in the future...

[braddock]

New Update, including a fairly stable 90 second tethered flight!
They also almost have the second vehicle ready to go.  They want to RACE them at XPrize Cup!

http://media.armadilloaerospace.com/2006_09_30/pixelAndTexel.jpg">

http://media.armadilloaerospace.com/2006_09_30/FOFflight.jpg">

Unfortunately, they can't do any untethered tests until the actual XPrize Competition, because it requires a launch permit.  Seems rather detrimental to safety if the FCC makes the launch permits so hard to get that the first real test flight will be right in front of a few thousand people.

[MKremer]

Racing would be cool!

Interesting that they've got an nVidia sponsor logo on the tank.
(wonder who ATI/AMD could want to sponsor? )

[braddock]

MKremer - 5/10/2006  4:08 PM
Interesting that they've got an nVidia sponsor logo on the tank.

And of course there are the rocket's names:
Pixel and Texel....

Too bad these rocket's lack Frustums and ViewPorts, but I hope they still have Vectors!

[Martin.cz]

They got nVidia to sponsor them
"NVIDIA is Armadillo Aerospace’s official sponsor for the X-Prize Cup events this year."
Carmack + nVidia + Rockets = best combination ever

[hop]

There's a new update http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=335

Looks like they are on track to have two flyable vehicles for the xprize cup this year.

[Spirit]

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

Good luck to Armadillo and his/their vehicle!

[meiza]

Spirit - 7/10/2006  10:39 PM

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

Good luck to Armadillo and his/their vehicle!

If the regulatory environment and companies are more relaxed in your country, you might get your hands on high test peroxide, which was Armadillo's first try anyway (you can read the archive posts on their site). It might be relatively easy to construct rocket engines with that, although it can be dangerous.

[hop]

Spirit - 7/10/2006  2:39 PM

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

It's not quite in your back yard, but you might want to check out http://www.arcaspace.ro/en/home.htm in Romania.

[braddock]

Here is a picture of Armadillo's would-be competition, Maston Space Systems.  They haven't test flown it yet.  They claim it is ready for first flight, but they didn't get their flight qualification and permit.

http://lunarlander.spaceracenews.com/wp-content/uploads/2006/10/masten.jpg">

Armadillo still hasn't gotten a permit for a flight at the X Prize.  They just did another 90 second flight yesterday, and will be trying for a 180 second flight today.

Carmack: "Flying at the cup is gated on the experimental permit. I suppose we might be able to do a tethered demo flight without it, but I’m certainly not going to pay for the insurance, consumables, and transport for a non-prize flight."

http://lunarlander.spaceracenews.com/?p=99

[braddock]

New update from Armadillo, always a must-read.
http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=340

Anyone wanna to go for a ride?  The saddle is installed.

http://media.armadilloaerospace.com/2007_01_03/saddle.jpg">

Also, apparently this is how you test after the police shut down testing at your shop and your neighbor shuts down testing at your farm:

http://media.armadilloaerospace.com/2007_01_03/horizontalTest.jpg">
http://media.armadilloaerospace.com/2007_01_03/horizontalCloseup.jpg">

They can't stop ya if they can't catch ya!

[meiza]

Graphite nozzle ("saddle"), the material between the cooling methanol and the expanding hot combustion products... it sounds like asking for trouble, why not go for aluminium? Their chamber pressure is low, it shouldn't be hard, no?

[jongoff]

Meiza,

Graphite nozzle ("saddle"), the material between the cooling methanol and the expanding hot combustion products... it sounds like asking for trouble, why not go for aluminium? Their chamber pressure is low, it shouldn't be hard, no?

Aluminum might be possible, but they had a lot of issues trying to make it work previously.  Copper would work fine.  His pressures are much lower than ours are, and our engine is smaller, which typically makes cooling harder, but after taking the data and doing the thermo, we got our very first regen cooled engine to work no problem.  In order to get aluminum to work though, he'd actually have to take a lot of data, and do the analysis right--aluminum is kind of marginal for the job.  

~Jonathan Goff
  Masten Space Systems

[braddock]

New Armadillo update is posted: http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=342

They are flying again, and with a regen engine no less.
http://media.armadilloaerospace.com/2007_02_05/groundLanding.wmv

Also, here is a VERY cool slowmo video of a tank burst test: http://media.armadilloaerospace.com/2007_02_05/tankBurst.mpg

"We made three good long flights with Pixel this month. There are three significant changes since the X-Prize Cup: new landing gear, regeneratively cooled engine, and new gimbal actuators."

"I’m happy to hear that a number of new teams are springing up looking to compete in the lunar lander challenge (I know of at least six prospects, outside of the 2006 entrants), but I think it is going to be a long shot for anyone to beat us to first place. "

Dem sounds like fight'n words, Jon...

[ericr]

What fun.   I want one too!

[josh_simonson]

braddock

Also, here is a VERY cool slowmo video of a tank burst test: http://media.armadilloaerospace.com/2007_02_05/tankBurst.mpg  

Looks like pac-man at a frat party!  

[publiusr]

The smaller these craft are--the faster they can get out from under you.