Callahan’s Express Rocket Recovery

The Callahan’s Express rocket was launched and lost at Tripoli Tampa’s Buccaneer’s Blast last month.   Here is the report on that launch. Like the Tampa Bay Lightning’s Ryan Callahan, this rocket took a beating.  Unlike the hockey player who has bounced back from numerous injuries and surgeries (and scored a goal last night), the Callahan’s Express has seen its last launch.

Callahan’s Express Rocket Recovery

Recovery

The launch was spectacular.  It flew straight as an arrow and hit 6,500 feet.  When the rocket neared apogee there were two events.  One of the events was the drogue chute ejection charge.  The second event is/was a mystery.

Landing

The main parachute somehow deployed at apogee and the flight line had a fun couple of minutes following the rocket on its way back to earth.  It drifted to the southeast and then veered back west.  It came down in a field just south of our launch area.  When I get to the touchdown site, I found a depression full of water up to my chest.

I tried a couple of times to reach it but could not.  I decided to wait until next month’s launch to try again.  This time of year in Florida is relatively dry and I hoped that the water would have dropped in the sinkhole.  It worked out well, the water was up to mid-thigh and I was able to get to the rocket.Out of the sinkhole - Callahan's Express Rocket Recovery

The Remains

As can be expected, a month submerged in water proved disastrous to the airframe.   This is especially true with humidity-sensitive Blue Tube material.   The electronics bay was intact but submerged.  The drogue parachute was made of heavy nylon and fared better than the main parachute which was rotten.

Here is what the electronics sled looked like when I opened the bay.  The poor StratoLoggerCF was covered in scum!Aviaonics Sled - Callahan’s Express Rocket Recovery

Launch Postmortem
Flight Plot - Callahan’s Express Rocket Recovery
Flight Data

Here is the good news.  After letting it dry and cleaning it with alcohol, the StratoLoggerCF powered up!  It started with a warning siren and then one beep.  That means the flight computer lost power during the flight.  I am really impressed with this computer and that’s why I wrote an ode to it earlier this year.

The drogue ejection charge fired, and the avionics lost power.   The main parachute charge did not fire.  This can be seen in the data and the main charge was found intact on the outside of the bay.

This still leaves the mystery of how the main parachute deployed.  I thought it may have been an airframe failure, but the rocket looked just fine when I recovered it.  The main ejection charge did not fire.

Unfired Main Parachute Charge - Callahan’s Express Rocket Recovery
Unfired Main Parachute Charge

One thing that may have happened is that I forgot to remove the ejection charge from the motor.  I cannot remember emptying the black powder from it.  I still cannot figure out how this would cause main parachute deployment as the motor was next to the drogue parachute.

The Good News

I got my 54mm Cesaroni motor case back.  After I cleaned it up and inspected it, it is ready for its next launch.  I recovered the Communication Specialist radio beacon.  Once it dried out, I put a new battery in it.  It is working fine.  The StratoLoggerCF is a write off.  It stored the last flight’s data, but I am concerned the water may have damaged the air pressure sensor.  I also got my drogue parachute back and most of the D-ring connectors.

Lessons Learned

  • Put a bullet on the dual-deploy checklist to empty the motor ejection charge.
  • Hard wire all the avionics connections.  No more connectors.

 

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