Experimental Sounding Rocket Association

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Update 11/24/09: 5th Intercollegiate Rocket Engineering Competition Advanced Category Announced: The Advanced Category for the 5th Intercollegiate Rocket Engineering Competition (5th IREC) will be to launch a 10-lb payload closest to 25,000 feet above ground level. Currently two university teams are planning on competing in the Advanced Category, and additional teams may be added as approved by ESRA. Interested teams should notify us via the Contact Us page.

Update 11/10/09: 5th Intercollegiate Rocket Engineering Competition Dates Set: The 5th Intercollegiate Rocket Engineering Competition (5th IREC) will be held June 16-19, 2010, near Green River, Utah. Early registration forms will be made available for reduced-fee preregistration soon. We have compiled an e-mail list of collegiate rocket teams that we will invite to the competition. If your college team wants to be included, please notify us via the Contact Us page.

Update 9/22/09: Tropos 2 Static Firing: We conducted a static firing of the Tropos 2 3" nitrous oxide/sugar motor on September 14 to test a new data acquisition system, main valve, and as a recruiting opportunity for the Rocket Club at Utah State University (smoke and fire!). The motor ignited well, indicating that we have the ignition problems solved, but "surged" repeatedly during the burn (see the data and a discussion here). We think it is because the main nitrous oxide valve we tested has too small a port, causing a pressure drop ahead of the injector. This probably caused three-phase flow (gas, liquid, and solid), causing intermittent partial clogging of the injector. We may go back to the old 3-piece valve, but it had some problems with leaking and being a bit too stiff for the spring to open consistently. It was also a bit heavier than the new valve. We may switch to a 2-piece valve--that decision has not been made yet. A new load cell ($1 university surplus!), in-house instrumentation amplifier ($10 in parts), and $50 data acquisition module were used with good results. It is interesting to note that the chamber pressure was less than in previous tests, yet the measured thrust was greater. We think part of this is because previous tests were done at an angle on the launch rail (with friction), whereas this test used a new horizontal "trapeze-style" test stand with minimal friction.

The USU Rocket Club decided they would like to rebuild the Tropos 2, and began work on new bulkheads immediately. We will work on getting an FAA waiver for a launch in early December.

Update 9/1/09: Tropos 2 Rebuild Effort Starts: With the start of the new school year, the Utah State University Experimental Sounding Rocket Club is starting work on the Tropos 2 again. Yesterday we tested the igniter design with 2-micron aluminum powder instead of magnesium. The igniters worked well, igniting by nichrome wire alone and burning with a 2-3 inch flame for approximately 12 seconds. We plan to do another static test of the 3" motor with the candy fuel grain on Sept 10. We plan to use the new horizontal test stand to gather more accurate thrust data.

Update 8/6/09: Reason for Tropos 2 Flight Failure Found: In preparation for the static firing at the 4th IREC, we reconfigured the motor with an electric valve and mounted the motor and tank on a horizontal test stand. Turns out that when we took apart the motor, the O-ring from the fill check valve had come off and was partially blocking the injector. So that would explain the apparent reduced thrust during the April flight. It may be that there was a combination of that plus the igniters being inadequate...it's possible that on the first ignition attempts during the launch attempt, the igniters couldn't ignite the full flow (the O-ring was still on the check valve). Then on the last attempt, the O-ring came off, restricted the flow, and the reduced flow rate was easier to ignite. We probably screwed up, because we noticed that the check valve was no longer sealing well on the last attempt, and should have put two and two together that the O-ring had come off and perhaps it could get into the main flow path. (The O-ring came off on a previous test. We got a new valve with a different O-ring material, but evidently that didn't help. The next check valve won't have an O-ring!). For the static firing at the competition, we had no check valve installed--just left the fill line connected. We are confident that the current igniter design works, though we may switch from magnesium in the igniters to aluminum because aluminum is easier to get.

The static firing demonstration at the competition went well. It was a demonstration only--no thrust data was collected.

Update 6/29/09: California State University - Long Beach wins 4th Intercollegiate Rocket Engineering Competition: The 4th Intercollegiate Rocket Engineering Competition (4th IREC) was held on June 25-26 near Green River, UT. California State University - Long Beach won first place and the University of Washington won second place and the Jim Furfaro Award for Technical Excellence. More details will be posted soon.

Update 6/14/09: Rocket Finding Transmitter Details Available: The Bridgerland Amateur Radio Club (BARC) will bring four 5-mile-range transmitters to the 4th IREC for use by teams to help locate their rockets after launch. This service is free, however there will be a $75 deposit required that will be returned if the transmitter is returned to BARC in good working order. More details are on the Competition Rules page, and a drawing of the transmitter is here.

Update 5/27/09: Rocket Competition and Workshop Status: The 4th IREC is on track for June 25-26, 2009, near Green River, Utah. We received the FAA waiver yesterday. UCLA has dropped out but California State University-Long Beach (CSULB) is planning to compete. CSULB has launched many rockets in concert with Garvey Spacecraft Corporation. Participants are Arizona State University, Brigham Young University, CSULB, Seattle Central Community College, University of Iowa, and University of Washington.

Due to the problems with the Tropos 2 hybrid rocket, we will not hold the Experimental Sounding Rocket Workshop before the Competition. In the next few weeks, we will continue to experiment with the igniters and conduct another motor static firing. This firing will use a horizontal "trapeze" type test stand to better measure thrust. We also hope to conduct a static test at the Competition as a demonstration (and to gather additional data). Once the propulsion issues are corrected, we will rebuild the Tropos 2 in the summer/fall.


Update 4/28/09: Disappointing Flight of Tropos 2 Hybrid Rocket:
ESRA and the Utah State University Experimental Sounding Rocket Club launched the "Tropos 2" hybrid rocket on April 25th. We had ignition troubles from the start, and on the third attempt, the rocket lifted off. But it didn't develop full thrust, climbed relatively slowly, and nosed over and flew more or less horizontally at an altitude of about 200 feet before impacting at a shallow angle about 500 feet from the launcher. The recovery sequence started, but didn't have enough time or altitude to fully deploy. The airframe and avionics were destroyed, but the parachutes, oxidizer tank, plumbing, and motor were mostly undamaged. Postflight examination showed that only 1/3 of the fuel was consumed. We believe it is due to a single igniter not being energetic enough to quickly, fully, and reliably ignite the motor (we used two igniters on the first attempt but only one fired--more details are on the Tropos 2 page). We plan to redesign the igniters and may do another static firing soon. But rebuilding the airframe will take longer.

Update 4/14/09: Successful Static Firing of "Tropos 2" Hybrid Motor: ESRA and students from the Utah State University Experimental Sounding Rocket Club successfully fired the caramel/nitrous oxide hybrid motor for the "Tropos 2" rocket being developed for future Experimental Sounding Rocket Workshops. The motor developed approximately 170 pounds of thrust and burned for approximately 17 seconds (with significant thrust--it burned much longer as the nitrous blew down). This successful test paves the way for a planned launch of the Tropos 2 on April 25th in Utah's west desert.

Update 3/18/09: Help with Rocket Finding at 4th IREC:
We are closer to having the Bridgerland Amateur Radio Club (BARC) help with locating rockets after launch at the 4th Intercollegiate Rocket Engineering Competition (4th IREC). BARC has purchased some small transmitters to place on the teams' rockets, and they will use their radio finding equipment to track the rockets during descent and locate them after they have reached the ground. A transmitter will be tested on the April test flight of the "Tropos 2" rocket being developed for future rocket Workshops by ESRA. Teams who elect to use this free service will most likely be asked to pay a deposit to cover the cost of the transmitter if it is not returned to BARC in working condition after the flight. Also, teams are still responsible for finding their rockets; BARC cannot be held responsible for loss of points, etc., if the rocket cannot be found within the 2-hour window.

Update 3/9/09: Insurance requirements clarified: Now that we have received the Bureau of Land Management permit, the insurance requirements for teams participating in the 4th Intercollegiate Rocket Engineering Competition (4th IREC) are more defined. They are summarized here.

Update 3/4/09: Strategic Space Development Sponsorship: Strategic Space Development has signed on as a sponsor for the 4th IREC.

Update 3/3/09: SpaceX Sponsorship:
Space Exploration Technologies, Inc. (SpaceX) will be a major sponsor for the 4th IREC. SpaceX has been a strong supporter of ESRA's competitions and educational outreach from the start.

Update 3/3/09: BLM Permit Received: We have received the permit allowing us to use Bureau of Land Management land for recovery of the rockets at the 4th Intercollegiate Rocket Engineering Competition (4th IREC).

Update 2/27/09: Planetary Systems Corporation Sponsorship: Planetary Systems Corporation will provide solar-powered recharging/power stations for the teams to use to keep their laptop computers running at the 4th Intercollegiate Rocket Engineering Competition (4th IREC). These stations will be available for "checkout" at the competition so teams can use them wherever needed.

Update 2/25/09: Cash prizes announced for 4th IREC: For the first time, cash prizes will be awarded at the 4th IREC: First Place, $250, Second Place, $150, Furfaro Award: $150. This in addition to the trophies to be presented and other sponsored prizes such as the G-Wiz flight computer for the Furfaro Award (see below).

Update 2/24/09: G-Wiz Flight Computers Sponsorship: G-Wiz Flight Computers will provide a top-of-the-line "HCX" flight computer to the winner of the Furfaro Award for Technical Excellence at the 4th IREC. This computer can read barometric altitude to 70,000+ feet, and can use acceleration to control recovery events even beyond that!

Update 2/18/09: We have finalized the registration fees for the 4th IREC and the Workshop (if it will be held; dependent on major test results on the Tropos 2 rocket). Click here for the IREC Registration fees and here for the Workshop fees.

Update 2/16/09:
We continue to work on the "Tropos 2" rocket that will be the basis of the 2009 Experimental Sounding Rocket Workshop if successful. For more details click here.

Update 1/21/09: The 4th Intercollegiate Rocket Engineering Competition (IREC) is scheduled for June 25-27, 2009, near Green River, Utah. It will include a Basic category where teams are to launch rockets with 10-lb payloads closest to 10,000 feet above ground level (AGL) and recover all rocket components intact. Pending FAA approval, it will also include an Advanced category for launches closest to 25,000 feet AGL. For more information, click here.

11/18/08: The 4th Intercollegiate Rocket Engineering Competition (IREC) is scheduled for June 25-27, 2009, near Green River, Utah. It will include a Basic category where teams are to launch rockets with 10-lb payloads closest to 10,000 feet above ground level (AGL) and recover all rocket components intact. Pending FAA approval, it will also include an Advanced category for launches closest to 25,000 feet AGL. For more information, click here.

11/18/08: Design work continues on the "Tropos 2" hybrid sounding rocket to be used as a prototype for colleges and universities who want to start new rocket programs. If development is successful and there is interest from potential participants, the Tropos 2 design will be used as the basis for a Sounding Rocket Design Workshop tentatively scheduled for immediately before the 2009 IREC. Schools interested in building rockets for future competitions can attend the Workshop and the IREC to jump-start their programs and get a feel for the competition. The Tropos 2 will serve as a baseline design that teams are welcome to modify as they see fit, and hopefully have rockets ready to fly for the following IREC. More information will follow. Anyone interested can contact us here.