The Draper Technology Digest - Draper Laboratory

FIGURE 5. CMATD electronics.Draper demonstrated system-level design and integrationon the Wide Area Surveillance Projectile (WASP)program, which developed a folding wing unmannedaerial vehicle (UAV) launched from a large-caliber cannon.The design included graphite-epoxy composite and metalelements with both bolted and bonded interfaces. Thesystem was designed with special attention to the pathof the expected loads as they propagated through thesystem. The fully deployed configuration of the WASPis shown in Figure 6.FIGURE 6. WASP UAV.Low Size, Weight, and Power Science InstrumentsNASA recently awarded a 2009 Planetary InstrumentDevelopment and Definition grant dubbed ASGARD(Advanced Seismometer, Gravimeter, and Accelerometerfor Rough Deployment) to a team led by DraperLaboratory. This three-year program will developcontrol electronics and further enhance the performanceof a third-party MEMS seismometer through successivebuilds and upgrades. The goal is to demonstrate asignificantly reduced noise floor over each year of theprogram. The program will further identify a pathforward for future improvement and hardening for theharsh space and other planetary environments.The ASGARD program is just finishing its first year ofdevelopment, which has developed control electronicsfor the first-generation MEMS device. This initialcharacterization will confirm that the instrument hasa noise floor of less than 100 ng/√Hz over 1-100 Hz.Although this is currently too high a noise floor foruse in a planetary geophysical sensor network, theyear 2 and 3 devices have noise floor goals of 10 and 5ng/√Hz, respectively. The intermediate noise floor goalhas already been demonstrated by the manufacturerand will be verified by the ASGARD year 2 efforts. Atthese lower noise floors, ASGARD starts to exhibitsignificant potential as a seismic instrument for planetarygeophysical sensor networks.In addition, the MEMS seismometer tested under theASGARD program is inherently impact-hardened. This,combined with Draper’s expertise in impact-hardenedsystems, should yield a highly sensitive impact-hardenedseismic instrument in a compact package. This makes itthe perfect mate as part of a penetrator-based planetarygeophysical network.CONCLUSIONSAs discussed above, electronics packaging methodsexist for high-g applications that can meet and exceedexpected planetary impacts. The experience gainedthrough development of defense-related applicationscan and should be applied to ruggedized landers forplanetary exploration. Penetrators may be furtherruggedized in order to reduce the overhead associatedwith descent modules and motors that would allow forthe deployment of a greater number of penetrators fora given mission. This additional redundancy, as wellas the ongoing progress in miniaturizing sensors forgeophysical networks, make penetrators an attractivemethod for future missions, particularly for geophysicalnetworks. More detailed analysis needs to be performedA Penetrator-Based Sensor Network for Planetary Geophysics59