Stretch Mustang First Flight

I got out to the NCR launch yesterday and did the first flight of the stretch mustang rocket on a G250 VMAX motor.  The altimeter reported an apogee of 1428 feet.  My original simulation predicted 1529, which is not too far off.  I can get an apogee of 1457 feet out of the simulator if I switch from smooth paint to regular paint, but there are probably other factors too.

My girlfriend also got her level 1 certification with her Wicked themed rocket “Defying Gravity”.


New Rocket Weight

The 6″ rocket is close to being all put together so I decided to get an updated weight for it.  It’s now 42.8 lbs.  The target is 45 lbs so I’m in good shape.  Both of those numbers are not including the motor, which according to the manufacturer’s web site is 5.8 lbs.  Here is the list of things that still need to be added:

  • Two CO2 cartridges for the parachute ejection system.
  • Electronics, including batteries.
  • Nuts and bolts to hold the coupler section to the body tubes.  I haven’t drilled the holes for those yet.


Recovery System Progress

I’ve been making progress on the recovery section of my 6″ diameter rocket.  The basic design is a CO2 cartridge, a solenoid, and some tubing blow off the nose cone.  Then a drogue chute pulls out the main chute.  Eventually, I’ll have something hold the shroud lines of the main chute so the rocket can fall on the drogue until low altitude.  But the first flights won’t be to that high altitude so I will let the drogue pull out the main parachute right away.

I got some brackets and mounted the CO2 cartridge/solenoid assemblies in the rocket.  There are two redundant systems.  It’s possible I might eventually use this rocket for my level 3 certification, and that requires redundant recovery system deployment.  The space is tight enough that I figured I should mount two from the start so I won’t get into the situation where I have to rework something to make it fit later.  Also, redundant deployment is good in its own right.

One nice feature of a totally pyro-free CO2 deployment system is that I don’t need to use kevlar webbing to resist the heat of a pyro charge.  Nylon will work just fine.

Why, yes, that is a ten centimeter square.

One of the nice things about a 6″ diameter rocket is that the diagonal of a ten centimeter square is 5.57″.  That means a cubesat can fit inside the rocket.  I’m building a payload bay into my nose cone that can hold a 3U cubesat.  I made a removable endcap for the nosecone that screws into a ring that’s epoxied into the nose cone.


My plan is to offer a free ride whenever I go out to fly to any educational or non-profit organization that has a cubesat.  The rocket will only go up a few thousand feet (up to a few tens of thousands if I complete all of the upgrades on my wish list.)  Still it will be a cool experience for students to see their cubesat fly on any rocket, and with the popularity of cubesats there may be a shortage of free rides.

In other news, life intervened and I couldn’t make it out to the launch this month either.  That’s still on the to-do list.