May 6, 2007 notes:
Sorry about the missed update last month, I was doing one of
my “working retreats” for Id, where I lock myself in an empty hotel room with a
computer to get a lot of uninterrupted work done, and I didn’t work my way out from
under the backlog pileup until half way through the month. I was still having trouble getting this one
done now…
Matt set up a cafepress shop for
Armadillo, so you can now get t-shirts again, as well as all the other various cafepress items. A
t-shirt probably pays for a few gallons of rocket propellant. J
http://www.cafepress.com/armadilloaero
Space Access
Space Access ’07 was enjoyable, as always. Matt had time this year to get another
Armadillo progress video together that covers the last two years of work:
http://media.armadilloaerospace.com/misc/sas07_high.mpg
This year was particularly interesting due to the many Lunar
Lander Challenge entrants present. Despite
there being nine teams registered for the Lunar Lander Challenge (up from four
last year), I still think there is a very good chance that we will be the only
competitors flying at the event. There
is a lot to be done. However, there are
several entrants that are very serious, and have all the resources necessary to
reach the goals, if not, perhaps, in time for this year’s event.
While much smaller in scope and grandeur, in some ways the
LLC is turning out more productive than the X-Prize. Despite some incorrectly reported figures in
the media, there wasn’t very broad development expenditure for the
X-Prize. Rutan
reportedly spent over $20 million, and I spend about $1.5 million, but I doubt
all the other teams put together actually spent more than $1 million in cold
cash. Sweat labor counts, but it
obviously didn’t cut it. All of the
serious LLC teams are planning to spend six figures in cash, as well as all the
labor, making it much broader based and more competitive. I also think that the more open nature of
most of the competitors is a very positive thing, and I like to believe that
the Armadillo example has had something to do with it.
Masten Space Systems
The Masten guys are almost
certainly the closest to getting another vehicle flying, but their prototype
vehicle won’t be capable of competing, so they will need to build a brand new
vehicle in the next few months. Dave
commented at the conference that they thought they were two weeks away from
flying the vehicle, but they had thought the exact same thing back in
October. Another month and a half has
gone by since he said that…
Paragon Labs
Kevin Sagis and I have been trading
email for a while now, and I have been really impressed. They have the best fabrication facilities of
any of the teams (better than us), and they have experience with solid rocket
powered attempted space shots, so they know how to do field ops and deal with
the FAA. Also as a very positive sign,
Kevin was still uncertain at SA whether he would actually enter, because he
knew how much work actually needed to be done, and wasn’t positive that they
could make it. A realistic grasp of the
effort required is very valuable.
Speed Up
I love the “rocket jet ski” approach for a commercial
direction, and I hope they can pull it off.
It has almost all the risk of suborbital flight for a fraction of the
profit, so it is a gutsier play, but Bob seems to be willing to have a go at
it. Sitting around at night after the
sessions, Bob, the Frontier guys (who are actually building the vehicles) and I
were talking about how cool it would be, and someone said something along the
lines of “Its Wyoming! We could put guns
on it!” Kidding. Mostly. J Being peroxide monopropellant based is the
only chance a brand new, from-scratch entrant really has to make it this
year. It really does make things a lot
easier. We sold them one of our old fiberglass
peroxide tanks a little while ago, so it would be quite ironic if they managed
to somehow snag first place at the level one prize away from us.
Unreasonable Rocket
I have always said that anything that we have done at
Armadillo could also be done for a quarter of our expenses if someone actually
tried to minimize cost in all ways. Paul
Breed Sr. and Jr. are going to try and verify that. However, there was always a caveat to my
statement – it will take longer. I don’t
think they can do it in time for this year.
You can’t help but pull for a father and son rocket team, though.
SBIR Award
Somewhat to our surprise, Armadillo was awarded an Air Force
SBIR contract. We made a fairly general
pitch about the virtues of a modular space launch system built in our current
style, and apparently they liked what they saw.
The fact that the two awards made for this round were to Armadillo and
XCOR seems to make the point that they want to get something that actually
flies. While phase I awards are really
just for studies, we will be generating a lot of flight and operational data
from the module work we were already doing.
If they decide to go forward with a phase II contract, we will deliver
some vehicles that they can actually USE.
I am of somewhat mixed opinions about SBIR work. In many ways they are sort of “life support
for small aerospace companies”, and I believe that many companies get stuck in
that rut, desperate for a tiny contract so they can keep the lights on and
their people employed, and they never make any real progress. Commercial work is preferable in a lot of
ways, but I don’t have nay personal issues with having the government as a
customer. We are going to do our best to
deliver real value for them, rather than just trying to efficiently suck out some
funding.
Neil is our point man for this effort, and he starts working
full time again this month. In addition
to managing the SBIR work, he is also busy preparing an experimental launch
permit for the modular vehicles, and we will be putting in for a full launch
license later this year. His day looks a
lot more like “real work” than the “playing with rockets” that the rest of us
do. Our various permits will be:
Experimental permit #2 (granted): dedicated for the Quad
flights at XPC ’06, now useless
Experimental permit #3 (granted): initially for Quad flights
at the Oklahoma
spaceport, will get an addendum for Quad flights at XPC ’07.
Experimental permit #??? : Single
module flights at Oklahoma and XPC ’07,
hopefully also covering two and four module flights at Oklahoma
and Spaceport America.
Launch License #??? : commercial revenue flights of one / two / four modules at
Spaceport America.
Various Improvements
We are continuing to work on various improvements to our
flight operations.
We currently use a fairly high flow electric pump to load
alcohol into the rockets, but we are testing a pressure loading option to shave
a few minutes off of the loading time.
This would add an operation to load the alcohol from the drums into the
pressure tanks at the fuel depot, but it saves prize clock time during
operations.
Matt and Phil have done a nice job integrating all the
receivers, signal conditioners, screen dividers, camcorders, and monitors for
the three camera video feeds coming from the vehicle into a single box with a
single cord. We did find that the signal
conditioners have some heat issues if they are left on for several hours at a
time.
http://media.armadilloaerospace.com/2007_05_02/goldBoxBaseStation.jpg
http://media.armadilloaerospace.com/2007_05_02/goldBoxBaseStation2.jpg
We had made a portable pole mount for our telemetry radio,
but lately all of our flying has been done with the control vehicle parked on asphalt,
so Tommy made a support box that lets us conveniently stick the Esteem
telemetry radio on top of my car. Using
power-over-ethernet is convenient for this.
http://media.armadilloaerospace.com/2007_05_02/esteemMount.jpg
I finally converted one of our electronics boxes over to
lithium ion and lithium polymer batteries, which saved 18 pounds. We have always used very large batteries for
the main computer, because it is a big benefit to be able to leave the computer
on essentially all day without having it run down.
We are going to try using some lighter weight landing legs
that are basically just leather covered foam pads. They can’t break, but the landing shock will
be greater. The trade off is that they
are over 20 pounds lighter than the super-reinforced shock based ones we tested
a couple months ago.
http://media.armadilloaerospace.com/2007_05_02/foamFeet.jpg
We made a nice new program to mill our igniter / engine
mount pegs, which we used to do mostly by hand.
We need to build at least seven engines to have the latest designs on
Pixel, Texel, and
the five modules under construction, so manufacturability is a big issue for
us. We included pre-drilled metering
orifices where the AN fittings for lox and fuel get welded on, so we no longer
need to use NOS metering jets on a cut down AN fitting. Russ added engraved lettering, so nobody has
to wonder which one is which.
http://media.armadilloaerospace.com/2007_05_02/igniter.jpg
http://media.armadilloaerospace.com/2007_05_02/tenIgniters.jpg
Our last attempt to fly a 180 second flight has a bit of a
bang on startup at the higher initial feed pressure, and we found that we had
cracked the graphite chamber (it still flew for two minutes before I shut it
down). To get more immediate ignition,
we changed from a single downward pointing igniter throat to four angled
throats that throw a flame jet more directly under the main injector elements.
Also after that last flight we found the bottom plate of the
engine slightly bowed out, so we decided to go ahead and finish the redesign of
our engine chamber that we had been planning for the modular vehicles. The new design uses a big Smalley snap ring
to retain the injector instead of a flange, and moves the fuel distribution
manifold inside the tube instead of outside, with the graphite chamber stepped
down to make room for it. This was seven
pounds lighter than the old engine, but more importantly it is easier to
manufacture consistently. We are also
using a Helicoflex metal seal instead of an o-ring at
the injector, to avoid the o-ring erosion we were seeing with Viton.
http://media.armadilloaerospace.com/2007_05_02/snapRingEngine.jpg
One thing that we should have started doing a long time ago
is hydrostatically proof testing our engines to well above the operating
pressure. When we took the first in-tube
engine up to 500 psi, the top closure bent a whole
lot more than we expected, so we redesigned it with a thicker plate.
Using the new engine, we did three 100+ second flights in a
row yesterday with everything working well, in full LLC trim with payload and
operating gold box. Each flight took a
little less than an hour, and we weren’t hurrying at all, so I think we are in
good shape for the contest time. We put
in a request to do untethered free flights at the
Oklahoma Spaceport next weekend, but the FAA is insisting on two weeks prior
notice to use our permit, which seems excessive and annoying. We are now requesting permitted flights every
single weekend for the rest of the year, which is probably not exactly what
they wanted. We are going to try and go
the following weekend, but the weekend after that is killed by the ISDC
conference (come see Pixel and meet some of the Armadillo crew if you are in
the area) and a meeting of the Personal Spaceflight Federation.
I expect that by the next update we will have full video of
us essentially “winning” the level 1 LLC.
We have every reason to believe that the new engine will handle level 2
as well. We get 120 seconds of flight
with a half propellant load, so 180+ seconds should be easy with the full load,
especially since the engine will be operating at a higher pressure while
burning all the extra propellant. We
have had something or another go wrong on each of our four attempts at 180
seconds so far, but the vehicle is getting better all the time.
Module Work
Module #1 is close to ready for hover testing. James has been doing a lot of work preparing
for production of these. We have a jig
structure that encloses the entire vehicle to guarantee that the inter-module
links, engine mount, and computer mount are all square and at the right
location.
http://media.armadilloaerospace.com/2007_05_02/jig.jpg
http://media.armadilloaerospace.com/2007_05_02/jig2.jpg
http://media.armadilloaerospace.com/2007_05_02/jig3.jpg
http://media.armadilloaerospace.com/2007_05_02/assembled.jpg (we missed getting a picture of it with the
engine and everything else on)
Assembly went fine with our concentric tube design. The lower (lox) tank has a 2.5” ID pipe going
through it with a metal bellows at the top to keep it from being stressed. The upper tank has a 2” OD tube with 1/8”
thick o-rings centering it going all the way through the bottom tank and hanging
free at the base. We have about a half
hour before the alcohol starts freezing in the pipe across the air-gap. With an ambient pressure air gap always
between the fluids, we don’t feel that it has the dangers of a common bulkhead
or conventional internal feed tube, and the assembly is quite elegant. Better pictures next update.
http://media.armadilloaerospace.com/2007_05_02/upperTank.jpg
http://media.armadilloaerospace.com/2007_05_02/manifolds.jpg
The legs have been a pretty big hassle to get right, but they
are almost done. The legs bolt on to the
inter-module mount points, but we want to be able to transport assembled single
modules, so the spread of the legs must fit within the DOT 102” maximum vehicle
width. The legs are fairly heavy, but we
want to be able to use them on four module systems, and the single module has
plenty of margin for 90 second level 1 LLC flights, so
we aren’t sweating it much. We can make
them with carbon fiber tubes if we wind up needing higher performance.
http://media.armadilloaerospace.com/2007_05_02/legTest.jpg
http://media.armadilloaerospace.com/2007_05_02/legMounts.jpg
We fabricated bolt-on pegs for our elevated tether testing,
which bolt opposite the upper leg mount at the module connecting blocks:
http://media.armadilloaerospace.com/2007_05_02/tetherMount.jpg
http://media.armadilloaerospace.com/2007_05_02/tetherMount2.jpg
We have plenty of Aspen Aerogel
insulation for all the modules and lots left over for patches:
http://media.armadilloaerospace.com/2007_05_02/insulation.jpg
BTW, congrats to the Up Aerospace guys for a successful
space shot in New Mexico!
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