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 bags usable volume.
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
Lots of work going on:
Changed the attitude engines up to 0.100 jets, because the
0.070 jets didnt 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
Check out the flight computer software under loss-of-signal
conditions, which we might hit in a flight.