Saturday, March 06, 2010

Working on Blue and....

Last week I fixed the landing gear on the blue ball in preparation for taking it to spaceup last week for show and tell. (You can see a picture of it there on its new gear here:

Last night I worked on building up a new cat pack. I started with the cat pack from silver and added some new disks. The top third of the cat pack was stripped and dead, I'm not sure what is going on. If I'm overheating the cat pack I'd expect the bottom third to be bad, not the top third. This leads me to believe I have some kind of contaminate in the h2o2. The new pack is ready to install.

My prep list looks like:
  • Remove the bottom half of the motor.
  • Grease lube and inspect bearings on the vanes.
  • Install cat pack in motor.
  • Replace seals in all the sanitary fittings. (This is preventive)
  • Reassemble the motor.
  • Replace the GPS antenna cable. (It has a kink at one of the ends.)
  • Inspect the wiring.
  • Build new Tethers.
  • Do a full electronics checkout.
  • Charge all the batteries . (computer, actuators, abort rx, telmetry box, laptop,2x rc transmitters, 3x cameras )
  • Do a tethered flight (on the 20th)
  • Do a free flight to about 1K ft. (maybe on the 20th)
  • Do a higher free flight???
I expect to finish all but the last four this weekend.

I have almost no traditional HPR experience with things like recovery high speed airframes etc... to remidy that I've been contemplating building a really simple H2O2 monoprop out of 4" or 6" aluminum tubing. Something that could go supersonic and reach to 20k ft or so. I'd use conventional dual stage recovery just like the big HPR guys do. This is something I can do with today's budget. Making the same basic vehicle bi-prop would make it capable of 100K ft.

It would probably be three increasing complex projects:
  • Unguided simple blow down mono prop to learn recovery.
  • Fin guided pressurized mono prop.
  • bi prop.
One of the really cool things I saw at spaceup was Ventions LLC small 100lb thermally
decomposed biprop h202 and RP-5 motors. Dr London had some cool video of it fireing on his phone. The motors were interesitng for both the construction and the thermal decomposition.
The were constructed out of stacked photo etched plates diffusion bonded together.

Getting a reliable thermal decomposed h2o2 motor to work would also be a really cool project.


heroineworshipper said...

Damn wire kinks. So many things in aerospace didn't matter in pure software.

AbodaOrganizer said...
This comment has been removed by the author.
Isaac Mooers said...

Here are a few innovative ideas I thought you could try:

1. Add a Toridial aerospike to the design, obviously regeneratively cooled.
2. Partner with flowmeterics to utilize Bio diesel JP-8/LOX, ideally using thier pistonless turbopump.
3. Since you can work with Lox you have the ability to work with ALICE Work up a hybrid booster design again with pistonless turbopump if needed.

Combine all 3 to make a 2 stage OTRAG style ALICE/LOX lower with spike. With a bio JP-8 lox upper with spike.

Put everything into the free google 3D rendering software. Document everything to patent office standards. Yet publish it under a copyleft style patent. Document all the work and ideally make videos of you doing it once the best way for each assembly step is determined.

End result much less complicated rocket with very common fuel sources not based on foreign oil, utilize as many off the shelf and duel use (for economies of scale) pieces of technology as possible.
Thus democratizing space access?

R2K said...

Love it, but more pics please!

Stevo Harrington said...

I would be happy to make you a small pistonless pump for your peroxide "HPR" rocket.
Peroxide would be easy to pump, compared to liquid oxygen.


Anonymous said...

Do you know if anyone has built a catalyst pack with a cross-section that gets smaller along its length?

This should lower the pressure inside the pack like a venturi, maybe encourage decomposition?

Term Paper said...

Very nice write up. Easy to understand and straight to the point.
I never thought of it like that, but it really is true.

Bob Steinke said...


Erik Bengtsson has more info now on his catalyst page,, he says the inlet end of a cat pack suffers more abrasion because of the two phase flow before the peroxide is all vaporized. Maybe that is what happened to the top third of your pack. He suggests solid silver instead of plated at the inlet end.