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.

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.

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.

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.

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.

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.

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.

by Osvaldo Tarditti, RRS President

USC Students came out to fly a rocket as part of the USC Poise Project (see more below). The students arrived Friday evening and camped out at the MTA to get an early start Saturday. The rocket took off around 11 am, followed by the recovery crew initiating a search. It was a beautiful day with no wind, it seems like the vehicle took a slight curved trajectory right after clearing the ramp. The rail may not have been perfectly straight and the speed might not have been fast enough to secure an initial straight trajectory. Further details from USC follow.

Poise Project Summary (by USC)

Poise is the sophomore design project of the 2018-2019 sophomore class. The project consists of a static fire and 6” diameter vehicle with an expected apogee of 34,000 feet. As a design project, Poise is not going for an altitude record, rather it serves as a test-bed for a handful of new R&D projects at a relatively smaller scale. While the static fire occurred in April of 2019, the vehicle launch has slipped into the 2019-2020 school-year due to the numerous design changes being tested. Compared to our proven technologies on Traveler IV, Poise features the following new innovations:

• A new “extrudable” propellant formula that is less viscous than RPL’s previous formula. This will serve for easier manufacturing of motor grains.
• A 2-part recovery system, where the rocket body and nosecone each have independent parachute systems. This is predicted to result in a smoother descent and minimize damage to the vehicle on descent.
• An additional, isolated avionics component called the “black box” placed in the camera bay. The black box contains a high-grade IMU in order to supplement avionics’ existing IMU and gyroscope data and increase precision and certainty when calculating apogee and flight path.
• The nozzle is made entirely of carbon phenolic, without a graphite insert at the throat. This drastically simplifies the nozzle manufacturing process while having very little predicted impact on the flight.

After review of GPS flight data, it has been determined that Poise reached an apogee of 31,090 ft! This was only 160 ft above the nominal prediction by our simulations team, which is an excellent estimation. While Poise’s trip up went incredibly, our new dual recovery system leaves work to be done. The nosecone (containing the main avionics components) was found, but the rocket body separated from its parachute on descent and has not yet been located. This section contained the GoPro cameras and the black box, which recorded additional flight data. Regardless of the loss of the body, the Poise project served as a test-bed for numerous development projects, a platform for RPL’s younger members to design a vehicle, and gives RPL much to improve on in the future.