October 15 and 19, 2002 Meeting Notes

 

 

Rocket Parachute Tests

 

We test fired our new rocket drawn parachute twice on Tuesday, with mixed results.  A single three grain Pro-38 motor mounted in the “escape tower” fashion was able to pull the chute out, but not as cleanly as we would like.  The tower plowed into the ground after pulling the chute out, breaking the body tube before it could eject its little chute.  We have made a new mounting block to hold two Pro-38 motors, which will give us a lot more pull, and a degree of redundancy.  We may need to angle the engines outwards to make better use of the thrust, but then a single motor firing may jam the tube in the vehicle.  The little rocket chute is now at the bottom of the deployment bag, so after the rocket pulls the bag completely off the main chute, its small chute will be pulled out, which will keep it from flying 5000’ away if it has a nice, straight deployment of the main chute.

 

Packing the parachute into the deployment back is definitely a pain, exacerbated by the fact that the tube section we fit the bag in is slightly smaller, which reduces the bag’s usable volume.

 

World Space Conference

 

We officially announced our entry into the X-Prize competition at a press conference at the WSC.  We are confident that we can build an X-Prize class vehicle before the prize expires at the end of 2004

 

Fabrication Work

 

Lots of work going on:

 

Changed the attitude engines up to 0.100” jets, because the 0.070” jets didn’t seem to have enough control authority at 250 psi tank pressure.  We may have an issue with rough running without much pressure drop across the jet when we test next.

 

Made polyethylene 2x4 blocks for “feet” for the wire rope isolators to raise the vehicle up some, and give it better skid behavior.

 

Fiberglassed the nose cone to the computer tube section, and epoxied the coupler ring down.

 

Russ finished the custom tank closures for the Structural fiberglass tanks.  With a 4” diameter, we are able to put several tapped holes directly on the closure, avoiding the need for a plumbing manifold.

 

We finished the fabrication work for the big vertical test stand.  We can bolt the shop press down outside and mount the test fixture on it for testing moderate sized monoprop engines, and move it to the cemented-in stand at the test site for big motors.  We should be testing both a 1000 lbf biprop and a 5000 lbf monoprop on this before the end of the year.

 

 

What we need to do before flying the tube to altitude:

 

Hydrotest the vehicle tank.

 

Bolt the aluminum engine / gear frame into the tail cone.

 

Test fire the new 2” nozzle monoprop engine on the test stand, should be 1000+ lbf at high pressure, and at least 400 lbf at 250 psi.

 

Hover test the vehicle.

 

At least two perfect parachute pull tests, fired by the flight computer.

 

Check out the flight computer software under loss-of-signal conditions, which we might hit in a flight.