Blast Initiation Detector Proof-Of-Concept Wind Tunnel Testing of Optical/Aeroshell Interface

摘要

Interceptors with fragmenting warheads that detonate in proximity to target vehicles are being used in missile defense tests. As part of this effort, it is necessary to be able to measure the performance of an interceptor during the endgame and it is preferable that the measurements be recorded independently from the interceptor telemetry. Target-based instrumentation and telemetry are used to provide this independent performance measurement. A Blast initiation Detector (BID) was developed for use onboard target vehicles to detect the initiation of the blast from the fragmenting warhead. The blast detection provides a target-centric temporal baseline for the final sequence of events during the intercept. The BID uses a circumferential array of six individual optical fibers attached to the surface of the target re-entry vehicle. The distal tip of each optical fiber protrudes beyond the surface of the aeroshell to provide the required optical field-of-view. Testing was used to address concerns of possible optical tip damage that could be induced by aerothermal loads. The optical fiber/aeroshell interface design of the BID was proven out by performing wind tunnel testing in a simulated aerothermal environment at the Avery Advanced Technology Development Laboratory by using two toggling laser beams at differing angles of incidence to simulate the blasts. The exposed distal tip of the optical fiber reached 1200 deg F during the worst aerothermal heating. The measured optical signals from the fibers indicated no significant degradation of performance and provided a proof-of-concept for the design of the optical/aeroshell interface of the BID.