September 5, 2004 notes:

 

Rejected NASA NOI

 

A couple years ago someone pointed me at this image:

http://history.nasa.gov/SP-4002/images/fig8.jpg

 

From the NASA history:

http://history.nasa.gov/SP-4002/contents.htm

 

I thought, “Hey, that looks rather like our manned lander…”

http://media.armadilloaerospace.com/2002_09_28/groupShot.jpg

 

Since then, I have often commented that something along those lines would be an excellent mobility tool for lunar or Martian exploration.  NASA recently put out a request for proposals for Human and Robotics Technology (H&RT) programs to further the current lunar directed exploration directive, so I decided to go ahead and make a pitch. 

 

http://www.exploration.nasa.gov/acquisition.html

 

It took a couple of readings to wade through all the acronyms and make some guesses at what they were actually looking for, but it seemed reasonably in line with what we are working on.  The submission process starts with sending a Notification Of Intent (NOI) to submit, which included a 700 or so word summary of the project and some information about the deliverables.  After the NOI, you make your full submission proposal, and they decide which projects get funded through a two-stage process.

 

It turns out I probably underestimated the importance of the NOI.  We planned to hire a professional to write the full proposal, because we don’t have enough (any) experience with NASA expectations, but I thought the NOI was just to see if we were even looking in the right direction.

 

My summary in the NOI:

 

Rocket powered ballistic roving is a technology with applications for both manned and unmanned transportation on both the moon and mars.  Even modest ballistic vehicles could provide rapid transportation over lunar ranges of hundreds of miles, and cover terrain impassible to ground vehicles.

 

Over the last four years, Armadillo Aerospace has independently developed several generations of vertical takeoff, vertical landing rocket ships ranging in size from forty pounds to over two thousand pounds.  Our work so far has focused on hovering translations and strictly vertical ballistic paths, but we propose to use our existing technologies to rapidly and cost effectively produce a proof of concept demonstrator capable of point to point transportation and return.  Our existing systems could be considered TRL 5, but they are not directly applicable as is.

 

An example of a recent vertical soft landed ballistic flight is at: http://media.armadilloaerospace.com/2004_06_15/perfectBoostedHop.mpg

 

An example of an older man-carrying ballistic vehicle is at:

http://media.armadilloaerospace.com/2002_09_28/firstMannedFlight.mpg

 

For an initial demonstrator, the primary unique challenges will be in modifying our flight control software to maneuver and thrust along ballistic trajectories with soft landings, and designing a robust vehicle configuration to survive the test program.  Our ongoing efforts at improving operability and manufacturability would continue with this vehicle.

 

Initial testing with the demonstrator would show multiple destination hops in the several-hundred-feet range, with a return to base for refueling.  Speed and range would be kept low enough to prevent it from becoming an aerodynamics experiment, but still cover enough range to adequately demonstrate the concept.  After an initial boost at moderate acceleration, the engine would be throttled down to still provide attitude stabilization until it is time to do the landing burn.

 

A trade study of various propellant combinations and vehicle configurations for an efficient lunar design would also be conducted, with extrapolations from the operation of the demonstrator vehicle giving greater confidence in the results.

 

We could pursue several different directions for phase II, and we would like feedback on which directions NASA would find most fruitful.  A truly space capable demonstrator could be fabricated and tested.  A manned vehicle could be demonstrated.  A telepresence ballistic rover could be operated in a lunar analog environment.

 

Moving to a different engine technology would require some effort on our part.  Our current vehicles use jet vanes under a single mixed-monoprop rocket engine, but we also have experience with 90% - 98% hydrogen peroxide monoprop and peroxide / kerosene biprop engines, as well as attitude control by dedicated thrusters or symmetric differential throttling.  We do not have any experience with cryogenic propellants.

 

Our current guidance system uses GPS to handle drift in the IMU that we use.  For proof of concept demonstrators this should be acceptable, but we would need to move to a higher end IMU for a true lunar capable vehicle.

 

We do not have experience in vacuum operation of our systems, but we plan on enclosing what we can in pressurized compartments.

 

Moving to bladder tanks may be helpful to the project.

 

Armadillo Aerospace is not an established government contractor, and our development approach will be considered unconventional, but we feel that we can provide excellent value to the program.  Our small team has a diverse composition, representing minorities, women, and veterans, and two team members are also educators.

 

NASA’s response:

 

John Carmack,

 

Your Notice of Intent (NOI) entitled Ballistic Rover Demonstartion has been reviewed by NASA.  The Agency received a tremendous number of NOIs (over 3,700) in response to the H&RT BAA.  Unfortunately, only a relative handful can be accepted to proceed to full proposal preparations.    Your NOI was determined to be very good and demonstrated acceptable understanding of requirements and approach that meets performance or capability standards. The NOI has no major weaknesses, several minor weaknesses, but sufficient strengths to balance and compensate for the minor weaknesses.  However, only NOIs rated as excellent or higher were invited to submit full proposals.

 

Therefore you are not requested to submit a full proposal for the Human and Robotics Technology BAA. 

 

Please continue to monitor our website for future opportunities.  On behalf of the H&RT Program we thank you for your participation.

 

Jimmie Nehman

Program Executive Officer

 

I was a bit disappointed at this, but I would rather get the brush off now instead of wasting a month and some money to prepare a proposal that would be rejected.

The list of all the NOI’s that they did accept (about 500):

http://www.exploration.nasa.gov/documents/accepts_post_0902.doc

Mountains of paper studies will be made, but it will be interesting to see how much actually gets built in the next few years.

Miscellaneous

 

We are still waiting on the tank for the new vehicle, as well as the machined manway flange and the rolled nose cone assembly.  I went ahead and ordered a second Crossbow IMU, so we should have a complete backup electronics system sitting on the shelf.

 

We are still having problems with the 7” engine combinations, and we have nearly exhausted the possible permutations we can make with them.  The latest builds will run smoothly for about five seconds, then go unstable, apparently when the hot pack reaches a certain temperature.  We could use the engines in their current form, but we would have to limit the throttle to a certain level to keep them running smooth.  We have a few more things to try, but all this aggravation is pushing us to look at biprops again.

 

Unstabilized 70% peroxide / kerosene with a cat pack and spark igniter is still the best bet for us, because we can still use the polyethylene lined tanks, and it should be easy to deep throttle.  While peroxide is normally shipped around at 70% concentration, it isn’t usually repackaged at that concentration.  I may need to buy an entire tank car load to get it.  We have been setting up our old 1000lbf aluminum biprop chamber for some tests in preparation for

 

I don’t think nitrous oxide offers much for us, because it is more expensive than peroxide, and offers worse system performance when you include the heavier tanks that are necessary at ambient temperature.

 

We may yet build a LOX engine.  I’m not sure any LOX engines have ever been demonstrated with a 5:1 or greater throttling range, but Charles Pooley proposed the interesting idea of making a lox preburner that vaporized all the lox before mixing most of the fuel, which gives a gas / liquid main combustion, which should throttle just like our cat-pack peroxide biprops.  We still think cryo propellants are something to be avoided if possible.

 

One of the things I had been thinking about in the context of the NASA submission was a purely gaseous hydrogen / oxygen rocket, which could easily use the presumed polar ice deposits.  You would probably also inject some water for extra cooling and improved mass fraction.  We built a few experiments to play around with this while we were between tests of the 7” mixed monoprop engine.  Separate injection of hydrogen and oxygen gave hot spots as the mixture ratio varied, but a coaxial injector worked great, and barely got hot during operation.  We set up our old 1” ID water cooled chamber and made a little rocket engine out of it.  It was an excellent demonstration of engine critical pressure, because we started by cranking the hydrogen pressure all the way up, then turning the oxygen pressure up.  It would start out as a fluffy blow torch, but as the oxygen was cranked up, it got louder and louder until the chamber reached critical pressure, at which point it instantly switched from a blow torch to a rocket engine with mach diamonds.  We might use a small combustor like this for a lox vaporizer.