Real-Time Full-Field Photogrammetry Implementation During the Mars 2020 Heat Shield Acceptance Test

This paper describes the first known attempt of implementing full-field photogrammetry during the acceptance test of critical flight hardware the size ( $\mathrm{D}=4.4 \mathrm{m}$ ) of the Mars 2020 heatshield carrier structure. Mars 2020, NASA's next science mission to Mars, uses a similar entry vehicle as the Mars Science Laboratory (MSL). In fact, the intention was that Mars 2020 would use the spare MSL heat shield (HS) structure. Unfortunately, the spare HS failed during proof-loading. The redesigned heat shield was proof loaded using a simpler load application method that enabled the use of photogrammetric measurements to be made on the entire outer mold line of the HS structure. In essence, full-field photogrammetry was used as real-time inspection technique during loading to guard against failure. Examples of how the real-time results were used to assess the health of the hardware as well as test/analysis correlation at critical load-holds are presented. Finally, advantages and limitations of the full-field measurement technique as applied to flight hardware acceptance tests are discussed.