Project Odyssey took place during the spring semester of 2015 after Pyralis ended. The twin vehicles - Scylla and Charybdis, won the IREC Basic Category in June 2015. Since the design, build, and test of this project took place in one semester, the project was streamlined by a primarily COTS booster.

Leadership:

Quick facts:

Testing

The recovery system was ground tested twice - once at an alumni's home prior to flight test 1, and once on the launch field prior to flight test 2.

Round 1

The first ground test was performed to verify the charge sizing. The verification was successful: the rocket separated with the tested charge sizes. However, flight test 1 did not experience drogue deployment. Post-flight analysis brought the conclusion that the drogue charge fired, but did not separate the motor section from the rest of the rocket. Potential causes include less combustion efficiency at altitude (at ~9800 ft, P_atm is ~70% of P_atm_MSL), and that forces on the rocket in flight made it more difficult to separate than in the ground test. At 1000 ft, the main charge fired and separated the sections, but since the rocket was ballistic prior to this, the main chute ripped, and the rest of the rocket didn't have time to slow down before it hit the ground. Flight Test 1 resulted in a near-total loss, but since the payload was not flown and we had (barely) enough time to make a new rocket, we geared up for ground/flight test 2.

Fixes implemented (see below):

• Drogue charge size doubled

Round 2

After consulting Woody, the Team decided to ensure the rocket was separated more aggressively than in ground test 1. We did this by doubling the primary charge size for the drogue section, which gave us the aggressive separation that was needed. (VIDEO?)  After the successful ground test, Scylla and Charybdis went on to fly to 9800 feet the same day. (VIDEO?/GIF?)

The recovery was successful, but not as planned. The fin can separated from the rocket at apogee as planned, but subsequently was removed when torques from the rocket body tumbling chaotically from apogee to 1000 feet caused the eye bolt at the top of the motor to unscrew. This resulted in a loss of a bulkhead, and nearly resulted in the loss of the motor section. Thankfully, it was found. The motor casing was re-used, but the fin can had to be remade prior to competition.  (PICTURE OF MOTOR SECTION STICKING OUT OF THE GROUND)

The avionics bay and parachute sections were recovered together. This section worked as planned.

Charybdis experienced main deployment at apogee, and drifted a significant distance from the launch site, landing in a tree. Some team members returned the following weekend to recover the payload from a tree. Climbing gear and expertise were required. (PICTURES?)

Fixes:

• Safety wire on the eye bolt for the motor section
• Swivel for main (drogue already had one)

IREC 2015

With two flight tests done, the Team went to IREC for the first time in 2015 to compete in the Basic Category. (PHOTO MONTAGE OF PRESENTATION, HOTEL, BUILD) (POSTER)

The presentation went smoothly, with 6 presenters. (Julia, Eric, Chris, Andrew A., Andrew K., ?) 

We attempted to launch on day 1. Integration was going relatively smoothly, and Charybdis was having a full functional run on the ground. The fins deployed, and after some deliberation, the decision was made to reset integration for the following day. There was some worry about losing the time slot, but it was taken care of by Julia.

The next day, everything was smooth. Recovery integration went well (Led by Connie L.), payload integrated, and the twin projects were, at last, competition ready. 

(PICTURE OF PRE-LAUNCH, LAUNCH)

The vehicles ascended to 9690 feet, and the recovery sequence occurred as planned for Scylla.  Charybdis drifted significantly from apogee, so its sequence was unclear - but it was found, fins deployed, with little damage apart from a broken fin. However, no data was found upon landing. The theory is that a loose connection caused the vehicle to power-cycle upon landing, causing the data to be overwritten. The Team received full marks for re-flyability. The efforts of Odyssey won us 1st place in the Basic Category.

(PICTURES)

On the last day, some team members went to Arches for a day trip.

IREC Poster

Lessons learned

Design/Build

• Leave more space than you think you'll need for recovery. And then add space. Test-pack your chutes.
• Milling the holes for the body tubes takes time, but is worth.

Testing

• Ensure separation for ground tests is vigorous. Dinky separation doesn't cut it.
• If there is an eye bolt for recovery, make sure it absolutely will not spin under torque. Safety wire or Loctite or epoxy it in place.
• Put swivels on all your chutes
• Add screamers if you can. Especially if you don't have telemetry.

IREC

• Be fully prepared to launch on day 1, but waiting a day is no big deal.
• IREC is really hot. We need to make sure our components can take the heat.
• Don't write a 3000-word checklist for recovery alone (but do write a detailed checklist)
• Don't do your first full functional test on competition day
• Data recovery needs to be assured!
• The flight tests won us the competition
• Arches is really freakin' cool and a good day trip