Armadillo Aerospace Update Thread

[NotGncDude]

Does anyone know why they use 4 pneumatic legs and not 3 or 5? If one leg fails to deploy, 3 others won't save the vehicle from tilting. Might as well either use 3 for mass savings or 5 for a degree of redundancy. But 4 is the worst choice. In case of old MOD, the 4 legs formed a structure that allowed for easy transport on a truck, I imagine. But now a supporting structure is necessary anyway. Or take another case, Masten had an airframe with 4 members, so 4 legs made structural sense for ease of design and building. None of this applies to new aeroshell MOD. I do not understand this design decision. Anyone has a good guess?

-- Pete

Actually 4 seems a good choice to me.  You assume that there is a significant chance of one leg failing to deploy.  It is not a significant threat at all.  They all run off the ullage pressure.  If one does not deploy then they all probably did not.  The craft would probably be salvageable in case of a tip-over. AA's rockets are next to bullet proof.  Highly reliable system = no need for five legs.

Four does however give a significant increase in stability over three.  At this point in their testing they just need to go fast in the thick part of the atmosphere to get a handle on dynamics. Mass fraction and performance are not a big issue until they got for 100km.  For now not having to bang dents out of tanks outweighs mass savings.

Though truthfully, their landings are accurate enough that three legs would probably be sufficient.  I do think that four was a good decision for a first go at a new technique.

What? This doesn't make sense. 4 legs don't increase stability at all. The only reason you put 4 is that you can make the vehicle tighter for the same tip-over angle. Other than that they are just heavier and decrease reliability.

[NotGncDude]

Where would people say Marsten and Armadillo are at present in relation to each other's progress. 
Marsten was more accurate landing in the comp' but with respect to their technology, it seems like they're running pretty much neck and neck.
Any thoughts?

Masten lost all their engineers. It's gonna take them a while to recover.

Disclaimer, before they get p**sed with me: Sure, they got new ones already, and they are great, no doubt, but these transitions take time.

ps. the censorship here is rather silly, they won't let me write pi**ed

[NotGncDude]

Does anyone know why they use 4 pneumatic legs and not 3 or 5? If one leg fails to deploy, 3 others won't save the vehicle from tilting. Might as well either use 3 for mass savings or 5 for a degree of redundancy. But 4 is the worst choice. In case of old MOD, the 4 legs formed a structure that allowed for easy transport on a truck, I imagine. But now a supporting structure is necessary anyway. Or take another case, Masten had an airframe with 4 members, so 4 legs made structural sense for ease of design and building. None of this applies to new aeroshell MOD. I do not understand this design decision. Anyone has a good guess?

-- Pete

Agreed. But...

The reason for 4 legs is that you can keep them closer to the structure than 3 legs. 3 legs have to be much longer which is a pain with deployable mechanisms (thin DCX, Blue Origin, LEM, etc). That's why Masten dropped the 3 legs from Xoie and went to 4 with Aero-xoie which is based on the same core.

[NotGncDude]

The staged deployment makes it kinda look like stop-motion animation!

@zaitcev: orthogonal structures are easier to design/build than isometric

To be fair, yes, it's also easier to build. That's good enough of a reason sometimes.

[Lars_J]

Am I the only one thinking that this flight looked a bit er... lacking in stability? Perhaps the software needs to be tweaked, or they did it on purpose, but it sure looked like the engine kept vectoring significantly back and forth through most of the ascent. The descent looked better though.

I also think that while the legs are technically long enough, the short length means that the engine nozzle is inches away from the ground - which might make throttling during the terminal landing a bit tricky. Perhaps it contributed to the 'jump' at the end.

But then again I could be waaaay off base.

[Zapp]

Am I the only one thinking that this flight looked a bit er... lacking in stability? Perhaps the software needs to be tweaked, or they did it on purpose, but it sure looked like the engine kept vectoring significantly back and forth through most of the ascent. The descent looked better though.

John Carmack on Twitter: "Excellent free flight with deployable legs. Behaves a bit differently, will tune control parameters before next flight."

[Zapp]

Does anyone know why they use 4 pneumatic legs and not 3 or 5? If one leg fails to deploy, 3 others won't save the vehicle from tilting. Might as well either use 3 for mass savings or 5 for a degree of redundancy. But 4 is the worst choice. In case of old MOD, the 4 legs formed a structure that allowed for easy transport on a truck, I imagine. But now a supporting structure is necessary anyway. Or take another case, Masten had an airframe with 4 members, so 4 legs made structural sense for ease of design and building. None of this applies to new aeroshell MOD. I do not understand this design decision. Anyone has a good guess?

-- Pete

Remember it is still a MOD and on them they use a four point mounting design for the enginebracket, so Im guessing four legs is the simplest/lightest way to do things without a whole redesign. Checkout the pictures on James Bauers flickrpage.
 
http://www.flickr.com/photos/29153024@N07/4895843083
http://www.flickr.com/photos/29153024@N07/4896439766

[jongoff]

Where would people say Marsten and Armadillo are at present in relation to each other's progress. 
Marsten was more accurate landing in the comp' but with respect to their technology, it seems like they're running pretty much neck and neck.
Any thoughts?

Masten lost all their engineers. It's gonna take them a while to recover.

Disclaimer, before they get p**sed with me: Sure, they got new ones already, and they are great, no doubt, but these transitions take time.

ps. the censorship here is rather silly, they won't let me write pi**ed

Note: this is probably a better topic for the Masten thread, but someone did ask about a Masten/Armadillo comparison.

Well, while they definitely had some pretty tough transition issues to work through, things are picking up again.  I was down there in Mojave for two weeks late last month training my replacement, Alex.  And I'm still available for consultation if they get stuck on any propulsion problem for too long.  Reuben's already up to speed pretty well.  He started the day I quit back at the start of July.  He was the crew chief for XCOR's X-Racer, and our systems while different are at least of a similar flavor.  He's pretty much up-to-speed by now.  Ian was definitely hard to replace, and that's where I expect the most transition challenges to come from, but his replacement George is pretty darned sharp too...

And don't forget that Ken and Dave are still there.  There's a lot of institutional knowledge between the two of them...

And the aeroshell stuff is finally coming through.  They had some snags and delays, but the intertank mockup piece got in (there were twitpics a few days ago).  The LOX tank and landing gear are done.  The engine is mostly ready to go back together.  The fuel tank is done. 

There still are a lot of bits and pieces to be done, the transition is a challenge, and they have a much smaller team, and far less resources.  But I think the approach they're taking is better (I'm very biased on that count though), so we'll see.  I think Armadillo may have pulled back into the lead, but you have to admit that when you compare their in-air relights, Masten's was a heck of a lot more graceful and crisp...

Masten is still definitely the underdog again, but they seem to do well in that position...

Ok, enough tooting my old horn there...

And...enough...ellipses...to...make...an...English...teacher...cry...

~Jon

[Zapp]

Another video from the latest flight

http://www.youtube.com/watch?v=k_Xiq3dYJlM&feature=youtu.be&hd=1

[mr. mark]

Excuse me but, I don't see where all of this is going. Spacex is already next year going to be delivering cargo to the ISS. Boeing's CST-100 is conceptually way ahead of this project and should be ready to put people in orbit around 2015. Virgin Galactic's Spaceship 2 is a much safer ride as far as passengers and is farther down the line than this. So where does this research fit in? I can see Lunar and possibly planetary lander possibilities but other than that? It seems their program needs more focus and direction as far as a ultimate destination. Sounds like they have corporate management problems and a need to communicate their ideas to the public better. As far as I can see they are in the same class as Copenhagen Suborbitals. Their launch was canceled by a hair dryer.

[mmeijeri]

And...enough...ellipses...to...make...an...English...teacher...cry...

Don't worry, you can't have spaceflight without tripping over conics.

[Lars_J]

Excuse me but, I don't see where all of this is going. Spacex is already next year going to be delivering cargo to the ISS. Boeing's CST-100 is conceptually way ahead of this project and should be ready to put people in orbit around 2015. Virgin Galactic's Spaceship 2 is a much safer ride as far as passengers and is farther down the line than this. So where does this research fit in? I can see Lunar and possibly planetary lander possibilities but other than that? It seems their program needs more focus and direction as far as a ultimate destination. Sounds like they have corporate management problems and a need to communicate their ideas to the public better. As far as I can see they are in the same class as Copenhagen Suborbitals. Their launch was canceled by a hair dryer.

If they aren't launching a capsule on an expendable rocket, what's the point? Is that what you are saying? 

If you *bothered* to do some research, you would know that orbital is a long-term goal of theirs. Once they gain confidence and experience with suborbital space hops, they have written about plans to put an expendable 2nd stage on top for orbital launches, and then take it from there.

But who needs low-cost RLVs, right? 

EDIT: Now I remember you - you're the same guy who complained that 'Copenhagen' was not valuing human life enough... I should not have bothered.

[Robotbeat]

Excuse me but, I don't see where all of this is going. Spacex is already next year going to be delivering cargo to the ISS. Boeing's CST-100 is conceptually way ahead of this project and should be ready to put people in orbit around 2015. Virgin Galactic's Spaceship 2 is a much safer ride as far as passengers and is farther down the line than this. So where does this research fit in? I can see Lunar and possibly planetary lander possibilities but other than that? It seems their program needs more focus and direction as far as a ultimate destination. Sounds like they have coprate management problems and a need to communicate their ideas to the public better. As far as I can see they are in the same class as Copenhagen Suborbitals. Their launch was canceled by a hair dryer.

Armadillo (and Masten, etc) have a very important role. Have you noticed how SpaceX, while still cheaper in some respects than ULA, still are around the same order of magnitude in cost?

We still have a long way to go. Arguably, work like that which Armadillo is doing is more important than what SpaceX is doing. Armadillo is practicing reusing rockets over and over again, focusing on a quick turnaround concept of operations. We aren't going to get truly cheap and reliable access to space without that capability. We just aren't.

Virgin Galactic will not be orbital for a long time, and their airlaunch technique is very expensive at a large enough scale to launch people into full orbit. They may get there eventually, but I think that Armadillo (and Masten) have an approach that is much more scalable and with lower capital costs.

Ultimately, the real reason their research is important is because you can't have a truly vibrant space economy with only one or two launch providers, even if they are inexpensive. You have to have diverse competition (though, since the industry is just starting to grow, a victory for one of these companies will actually probably help the others as well).

And the retractable legs are important to reduce the drag, because very soon these folks are going to go past the Kármán line (and back, safely), and to get there they will need to go supersonic.

[butters]

Excuse me but, I don't see where all of this is going. Spacex is already next year going to be delivering cargo to the ISS. Boeing's CST-100 is conceptually way ahead of this project and should be ready to put people in orbit around 2015. Virgin Galactic's Spaceship 2 is a much safer ride as far as passengers and is farther down the line than this. So where does this research fit in? I can see Lunar and possibly planetary lander possibilities but other than that? It seems their program needs more focus and direction as far as a ultimate destination. Sounds like they have corporate management problems and a need to communicate their ideas to the public better. As far as I can see they are in the same class as Copenhagen Suborbitals. Their launch was canceled by a hair dryer.

Their intention is short-duration microgravity and (maybe) vacuum experiments.  Like an advanced reusable sounding rocket.  Their objective is suborbital (at least for the foreseeable future), so it makes little sense to compare them to SpaceX or Boeing.

[NotGncDude]

Where would people say Marsten and Armadillo are at present in relation to each other's progress. 
Marsten was more accurate landing in the comp' but with respect to their technology, it seems like they're running pretty much neck and neck.
Any thoughts?

Masten lost all their engineers. It's gonna take them a while to recover.

Disclaimer, before they get p**sed with me: Sure, they got new ones already, and they are great, no doubt, but these transitions take time.

ps. the censorship here is rather silly, they won't let me write pi**ed

Note: this is probably a better topic for the Masten thread, but someone did ask about a Masten/Armadillo comparison.

Well, while they definitely had some pretty tough transition issues to work through, things are picking up again.  I was down there in Mojave for two weeks late last month training my replacement, Alex.  And I'm still available for consultation if they get stuck on any propulsion problem for too long.  Reuben's already up to speed pretty well.  He started the day I quit back at the start of July.  He was the crew chief for XCOR's X-Racer, and our systems while different are at least of a similar flavor.  He's pretty much up-to-speed by now.  Ian was definitely hard to replace, and that's where I expect the most transition challenges to come from, but his replacement George is pretty darned sharp too...

Sorry Jon I knew this was going to get me in trouble. I agree with this, all I'm saying is that these transitions slow down progress for a bit. In any case, it's an Armadillo thread so I'll shut up.

[Zapp]

sounds like they just flew again, twitter:
ArmadilloGadget(Phil Eaton): Awesome flight! Ben will have video later.

[kch]

And...enough...ellipses...to...make...an...English...teacher...cry...

Don't worry, you can't have spaceflight without tripping over conics.

And a good thing, too -- who'd want to get "Hooked on Conics"? 

[savuporo]

Here we have a great Heinleinian rocketship rehearsing its landings, poised to start flying out of the atmosphere .. and all you guys do is argue about how many legs it should have !



EDIT: seeing this one flying, reminded me about the ISAS/JAXA RVT program again, i wonder how these guys are progressing:
http://ina-lab.isas.jaxa.jp/about/index_e.html

There hasnt been a test flight in a long time.

[Zapp]

twitter: ID_AA_Carmack: We repeated the rocket flight this morning with the addition of having it land offset from the liftoff point and some other changes.

[zaitcev]

Here we have a great Heinleinian rocketship rehearsing its landings, poised to start flying out of the atmosphere .. and all you guys do is argue about how many legs it should have !

Who knows, perhaps one of us is going to have to make a decision in the future, and judgement is not something found in a textbook.

That said, I just noticed that PPTK NP also has 4 legs (they unfold from the bottom to the outside, in the opposite direction to RXVT).

-- Pete