1、Lessons Learned Entry: 1533Lesson Info:a71 Lesson Number: 1533a71 Lesson Date: 2005-04-29a71 Submitting Organization: DFRCa71 Submitted by: Trong BuiSubject: Securing Antennae for Homing Radio Beacon Transmitters Abstract: The Dryden Aerospike Rocket Test Directors Discretionary Fund (DDF) project c
2、onducted flight research of an aerospike rocket nozzle design using high power amateur rockets. The standard nozzles in these rockets were replaced by the aerospike nozzles and the rockets are then flown with aerospike nozzles only. Two aerospike rockets were flown successfully to altitudes of over
3、26,000 ft and speeds of over Mach 1.5. The flight data acquired during the flight tests were stored onboard and retrieved after the rockets were recovered. To help locate the rockets after they landed and homing radio beacon transmitters were installed on the recovery parachute harness. Two homing r
4、adio beacon transmitters were used. They were made by different manufacturers and operated on two different frequencies. An antenna broke from one of the transmitters, causing it to stop transmitting. The rocket was found using the radio signal from the remaining operative transmitter.Description of
5、 Driving Event: The broken transmitter was mounted on the rockets parachute harness. However, its antenna was not secured. During the parachute deployment, the forces and accelerations that occurred caused the antenna to break off from the transmitter. As a result, the transmitter ceased transmittin
6、g, and the rocket was found using the radio signal from the remaining operative transmitter.Lesson(s) Learned: Homing radio beacon transmitters can lose their antennae and stop transmittingRecommendation(s): Secure homing radio beacon transmitter as well as its antenna so that the antenna will not b
7、reak apart Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-during ejection of the rocket nosecone. At least two homing radio beacon transmitters operating on two different frequencies are required for redundancy. Evidence of Recurrence Control Effect
8、iveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Sciencea71 Space Operationsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Accident Investigationa71 Communication Systemsa71 Flight Operationsa71 Payloadsa71 Safety & Mission Assurancea71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 2005-08-29a71 Approval Name: Mike Reljaa71 Approval Organization: DFRCa71 Approval Phone Number: 661-276-3621Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-