Stardust Entry Reconstruction

An overview of the reconstruction analyses performed for the Stardust capsule entry is described. The results indicate that the actual entry was very close to the preentry predictions. The capsule landed 8.1 km north northwest of the desired target at the Utah Test and Training Range. Analyses of infrared video footage and radar range data (obtained from tracking stations) during the descent show that the drogue parachute deployment was 4.8 s later than the preentry prediction, whereas the main parachute deployment was 19.3 s earlier than the preset timer, indicating that the main deployment was actually triggered by the backup baroswitch. Reconstruction of a best estimated trajectory revealed that the aerodynamic drag experienced by the capsule during hypersonic flight was within 1% of preentry predictions. Observations of the heatshield support the preentry estimates of small hypersonic angles of attack, because there was very little, if any, charring of the shoulder region or the aftbody. Through this investigation, an overall assertion can be made that all the data gathered from the Stardust capsule entry were consistent with flight performance close to nominal preentry predictions. Consequently, the design principles and methodologies used for the flight dynamics, aerodynamics, and aerothermodynamics analyses have been corroborated.