MTA launch, 2020-02-01

by Dave Nordling, RRS.ORG

The RRS met at the Mojave Test Area for our third launch event of the year in successive weeks. We were glad to host UCLA’s Project Ares for another static fire test of their liquid rocket.  The team has worked hard to improve their design from last year and had just presented their Critical Design Review (CDR) to peer review.

UCLA completes their on-campus CDR for the latest design of Project Ares
UCLA stands in their lab getting ready for the next hot-fire

The second project for the day was to be my hybrid rocket that I have built with Larry Hoffing.  The commercial H222 model from Contrails Rocketry is built into an old 2.5-inch rocket body that Larry had on hand.  I had some missing fluid connectors at the last attempt and it was my hope that this next attempt with the motor successfully loaded and a parachute recovery system in place, this would be the first hybrid launch from the RRS MTA in many years.

Larry Hoffing measures out a small powder load for the parachute deployment

Osvaldo had made a two-channel switchbox using an extension cord for controlling the nitrous oxide fill and drain solenoid valves.  The unit worked very well in system checks and we were to use our existing firing box for ignition.

Osvaldo cycles the solenoids using our new fluid flow control box

After a successful leak check of the manifold under pressure, we had a serious mishap with the nitrous bottle during a solenoid valve test resulting in loss of our stored oxidizer propellant. We surveyed the situation with our pyro-op and realized our error. With some minor repairs to the manifold, replacing a gauge and recharging the nitrous bottle, the fluid system will be restored.

Dave Crisalli, our pyro-op in charge at the RRS, talks with UCLA as they are setting up

Larry and I proceeded to complete the parachute recovery system to verify all systems are present and functioning.  I chose a MissileWorks RRC2+ dual-deployment system for parachute recovery using only the drogue chute circuit and all settings in default mode.  We also had an old Jolly Logic altimeter chip as a backup for the system.  All electronics passed inspection and we began a packaging check after securing the vent line stub.  At the end of checks, we felt the payload space was too tight and with our launch attempt already scrubbed we sought to make some improvements to the recovery system.

Parachute deployment for the hybrid rocket
Laying out the parachute with a Nomex cloth for heat protection from the powder charge

The RRS hybrid rocket launch will have to wait for the next launch event. We’ll make some improvements and hopefully have success soon.

The remainder of the day was spent overseeing UCLA’s next attempt with their ethanol/LOX liquid rocket. The team has had modest success with their prior hotfire in November but was looking to demonstrate further improvements.

Anneliese Peterson of UCLA installs the relief valves into the propellant feed system
Dave Crisalli discusses progress with UCLA’s design from within the safety of the George Garboden observation bunker

UCLA discovered and repaired several leaks in their pressurant connections. They also successfully purged their propellant tanks and had reached the decision point whether to proceed with LOX loading.

Based on a thorough discussion by the team and with our pyro-op in charge, UCLA opted not to proceed with hot-fire preparations and will make further corrections to their rocket systems before returning to the RRS MTA in the coming weeks.

UCLA showed great teamwork and maturity in their decision on how to best proceed. A future hot-fire date hasn’t been set yet, but the RRS is ready to support. 

It wasn’t a great day for hot-firing but many felt something important was learned that day at the RRS MTA. We will likely be back again sometime this month.  Wolfram Blume may be ready to conduct his first system test flight by then and Larry and I certainly will be ready to try again with our hybrid.  UCLA will also likely return this month.  The next launch event with LAPD CSP will be coming in March. 

In all cases, groups wanting to use the RRS MTA must contact the RRS president and submit a standard record form. We require a minimum of three weeks notice to consider all requests.

Our next meeting will be 2/14/2020 as the second Friday falls on Valentine’s Day this year.  We will surely discuss the MTA events since our last meeting including this one.

Thanks to everyone who came out and made this a great day.

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