On Saturday, April 12, 2008, California State University, Long Beach (CSULB) and industry partner Garvey Spacecraft Corporation (GSC) jointly conducted a flight test of the Prospector 14 LOX-Methane (P-14LM) prototype launch vehicle that featured a 1,000 lbf-thrust LOX/methane rocket engine developed by CSULB students. It is believed that this is the first such powered flight of this cryogenic propellant combination, which is under consideration for applications in a variety of future space exploration initiatives, such as those funded by NASA for future RCS and in-space main propulsion systems. It is preferred to current storable systems because of its non-toxicity, its high performance, and because methane could be manufactured on Mars.
The flight test was conducted as part of the joint CSULB/GSC CALVEIN (CAlifornia Launch Vehicle Education INitiatve) and was supported entirely by internal team resources. It took place at the Friends of Amateur Rocketry (FAR) test site outside of Mojave, CA.
P-14LM in flight, powered by LOX/methane
A first version of the engine was developed by undergraduate students James Okofu, Jason Ellert a nd Anup K. Sandeep Dev as part of their senior design project in 2006-07, with additional participation of Deepak Verma and Akihiro Shibuya. James Okofu and Deepak Verma benefited from a CSULB Provost's Undergraduate Student Summer Stipend for Research to complete the engine and prepare the flight vehicle. The engine features a flat head injector with split triplets and some fuel film cooling is used to limit ablation rates of the carbon-fiber over-wrapped silica-epoxy ablative chamber.
In order to reduce costs, the decision was made to forgo traditional static fire tests and go directly into flight. The engine was integrated into the retrofitted Prospector-1 rocket, the first prototype vehicle developed and launched by the CALVEIN team back in 2001. This vehicle, modified for methane operations, became the P-14-LM (while P-1 through P-8 have flown, some as many as 4 times, P-9, P-10, P-11 and P-12 are slated to fly between May and Sept. 2008).
While the rocket and engine could have been ready for flight in the summer of 2007, several additional months were needed to find a suitable source of methane. Liquefied natural gas (LNG) was used for this project.
A first attempt to conduct the flight test with the first version of the engine finally took place on March 29, 2008 at FAR. In this initial configuration, ignition was performed via a lance-type device inserted through the throat. The test resulted in a "hard-start", leading to an explosion of the engine. Over the following two weeks, with the critical efforts of George Haberstroh, student lead for the larger 4,500 lbf-thrust engine, CALVEIN members fixed the aft end of the vehicle, implemented design changes for reliable engine ignition and manufactured a new engine for this April 12, 2008 flight test.
The wet vehicle weighed at approximately 120 lb and operated in a blow-down mode, with about half of the tanks filled with propellant. Tank pressure was set such that the engine thrust would be reduced from the 1,000 lbf design point in order to limit liftoff thrust-to-weight ratio to about 6 g's. Burn time was 5-6 s and the vehicle reached an altitude of approximately 5,500 ft above ground level before a parachute was deployed for recovery. Work is now is progress to extract and analyze data from the flight test.
This project exemplifies the approach used by the CALVEIN team towards meeting the objectives of developing new technologies while also engaging students by conducting frequent in-field operations and providing opportunities for quick iterations. Back in September 2003, the engine on the first flight of an aerospike rocket engine experienced an anomaly. A design fix was rapidly implemented and resulted two months later in a flawless flight test. Here, iteration from first test to engine design revision, manufacturing and vehicle integration was performed in 2 weeks. This rapid turn around provided students with an opportunity for iterating on their design rather than waiting for a new team of students to come in the new academic year and allowed them to complete their project successfully.
As noted above, the past few years have seen an increased interest in using LOX/methane as rocket propellants for a variety of applications with most of the funding coming from NASA:
Also, South Koreans have developed a LOX/methane engine which was ground tested.
Several RLV-related demonstration flights are planned for this vehicle as a follow-on to the Prospector 7 under GSC's Phase II SBIR program with AFRL/PR and SMC where CSULB participates as major partner. The P-9 configuration features several major improvements over the previous NLV / RLV prototypes, including the 4.5K lbf-thrust engine previously demonstrated on the P-8 and full-scale composite propellant tanks from Scorpius SLC. Future configurations will have even more capability once thrust vector control is implemented. The first set of low-altitude P-9 flight tests are now scheduled for mid-2008 pending clearance of several programmatic milestones.
The P-10A features a next-generation aerospike engine with 10 individual ceramic matrix composite thrust chambers and is in the final phases of integration for a near-term static fire test. This project is funded by the Missile Defense Agency.
Wireless networking testbed vehicle for NASA Ames. Launch is anticipated in mid-2008
This will be the second vehicle development and flight project sponsored under Task 3.3. of the U.S. Department of Labor / California Space Authority's WIRED program. Objectives include student mentoring and the manifesting of payloads from other WIRED partners. Launch is scheduled for September 2008.