Tripoli Williams July 25 2009 Launch Report

So I went down to Williams Valley on Saturday for my first Tripoli launch. Gotta say it was a great time. Here's the breakdown of the day.


Semi-scale goodness on the table

My first rocket off the pad was the inaugural launch of my Binder Thug. It's got a 38mm motor mount and I started with a H242T with a medium delay. Rocksim calculated apogee at ~2350ft with a max velocity of ~562 ft/sec. The T designation of the motor stands for Blue Thunder propellant which happens to burn very quickly. The motor has 230N-sec of total impulse peaking at ~60 pounds of thrust at just after motor ignition. Motor burn time is approximately 1.3 seconds in length.


Binder on a H242

The launch was completely successful with deployment just after apogee. That said recovery isn't always easy. The Thug ended up in a tree that I had to climb to recover it. Thanks go to Steve for assistance in locating the rocket as well as finding a suitable branch to use to get the thing down.


Amraam on the pad

Next launch was the AMRAAM. Let's just say the rocket gods were against it going up, and I should have listened. I went through five igniters trying to light the G64 in the Rouse Tech reloadable motor. When the fifth igniter finally lit, so did the rocket. CATO. Catastrophe At Take Off! The forward closure of the motor failed. I think it was due to the forward o-ring or forward insulator not seated properly against the propellant. I should have checked the entire motor after changing the ingitors so many times. RIP AMRAAM, you served me well.


Cato
If you look closely, you can see the nose cone already separating from the body.


Here's how it ended up, ~25 meters from the launch pad. I had to step on the forward part of the body tube to put the fire out!


forward closure
On the left is a 29mm RMS forward closure in good condition, on the right is the one that blew.


So after a tree climb as well as a spectacular CATO, I figured I'd leave the Thug on the bench and fly the Snarky. I dove into the rocket box and pulled out a 3 pack of F39T-6's. They have 50N-sec total impulse, a peak of ~13 pounds of thrust, and a burn time of 1.5 seconds. Rocksim estimates the flights reached apogee at ~1130 ft with max velocity of 460 ft/sec. I've got to give it credit, this little thing flies fantastically. The air scoop provides stabilisation so it always flies straight up and noses over fantastically to resemble flight. Recovery works great using blast protectors with a few sheets of wadding or dog barf and is much simpler than pistons or baffles. I flew the Snarky a total of 3 times on the day, all on F39's.


Snarky Launch
Photo was taken just as the F39 Blue Thunder lit.


Snarky recovery


Finally I thought you might like to see what Rocksim looks like. Here's the motor tables for my Thug and Snarky.


Binder Thug Rocksim file


Snarky Rocksim

A big thanks goes out to all the team at Tripoli, especially Dave, the Tripoli WA Prefect, Mel aka the Queen of Coordination, Neil aka the media guru, and Steve the Rocket hound.

That pretty much wraps it up. I've started on a 38mm PML Bullpup as well as a Estes Patriot modified with a 24mm mount and baffle. I figure I need to replace the AMRAAM with something scale and sizeable. Plus I've got the Initiator that still hasn't flown for the 29mm motors I still have in the rocket box. Time to start preparing for the next launch!

July 12 2009 PARC launch

It's taken me a while to get to this, here's a summary of my latest launches. We went up to the field a bit late and it was pretty windy but that didn't stop us. I only launched the AMRAAM, twice on G64-7W's and once on a H238-T with a medium delay. On the second G64 launch I attached the internal payload bay I've built for my Pico AA-1 accelerometer based altimeter. I'll do another post detailing my results shortly.

The H238 launch was for my Level 1 Certification. The motor had a total impulse of 175N-sec and burned out in under 0.8 seconds. It was a Blue Thunder propellent type, the first one of these I've launched. Talk about a quick burn! I was lucky enough to recover my AMRAAM intact after the launch. I say lucky because it destroyed one of the Mantis pads in the process. Guess they just don't have the strength to handle the thrust of high power motors! Have a look at the pics below as well as the little vid of the H launch.

On the pad, loaded with a G64.


Ready to go beside a James's Loc V2.


G64 launch, Thanks goes to James for the rest of these shots. I'm going to have to get a nice DSLR soon I reckon.


Gaining altitude...



Still going, those G64's burn for nearly 2.5 seconds.
Here is a cropped image of the previous photo to give more detail.


Some of the less impressed spectators.


Here's a shot of the launch field. I'm not 100% certain, but I think this is the launch of Rich and Atla's Grappler as well as my 2nd Amraam launch of the day. The Grappler is above, with my Amraam just coming off the pad.

Last but definitely not least, here's my L1 launch on the H238.



A big thanks goes to Rich and Atla. Cheers to James for the high res shots and PARC for supervising my L1. Now I can launch motors up to 640 N-sec. Sweet.