Search NASA⌕ Search

Engineering topics

Samantha Applin

Publications and source records attributed to Samantha Applin.

3 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

TPSAS-NF1676L-31522-DND

Currently, there are limitations in launch capability regarding requisite payload volume and mass for long duration extra-terrestrial missions. In-space additive manufacturing may provide a solution to this challenge and is applicable for articles ranging from large system and subsystem architectures to small consumables and replacement articles. For small articles, additive manufacturing is becoming more feasible through advances in instrumentation and novel manufacturing strategies capable of generating complex shapes. Many approaches, however, utilize feedstock materials that, once consumed, must be replenished before additional architectures can be generated. Thus, although promising, a major challenge with additive manufacturing is the required starting materials to support on-demand article generation. This presentation describes research toward reversibly assembling materials that can revert to the starting material state for subsequent fabrication. Polyimides were synthesized with thermally reversible Diels-Alder reaction functionalities, furan or maleimide moieties. These materials were characterized utilizing typical spectroscopic, thermal, and mechanical techniques. Amine hardener-enriched epoxy microparticles were synthesized for use as a mechanically robust substrate. Integration of these technologies into a single system and application toward generation of secondary structures on a launch vehicle as a means of in-situ resource utilization will be described.

Christopher J. Wohl↗
NASA NTRSDate not supplied

Aerosol Wind Profiler (AWP) Doppler Wind Lidar Airborne Observations During the NOAA Joint Venture 3-D Wind Measurement Demonstration and NASA Active-Passive Profiling Experiment (APEX)

The NASA Langley Research Center (LaRC) has recently completed development of the Aerosol Wind Profiler (AWP) airborne Doppler wind lidar (DWL) instrument. AWP was supported by the NASA Earth Science Technology Office and the Earth Science Division, a project that adapted the Wind-Space Pathfinder (Wind-SP) DWL transceiver onto a structure for flight aboard a variety of NASA research aircraft. AWP demonstrates many technologies required for a space DWL mission, including a coherent-detection, optical heterodyne laser transmitter with high pulse energy (up to ~55 mJ) and repetition rate (200 Hz), electronic control of the beam path allowing for multiple viewing angles (allowing vector wind measurements) with no moving parts, compact highly-stable and tunable reference lasers allowing for high-precision measurement of velocity at long ranges while mitigating the impact of satellite platform velocity, and many others. AWP represents NASA’s only currently operational airborne 3-D wind profiling sensor. NASA LaRC was selected by the NOAA Joint Venture (JV) program to conduct a suborbital 3-D Wind measurement campaign demonstrate how data from a coherent-detection DWL like AWP could serve NOAA’s weather analysis and forecasting needs. The NOAA JV program is designed to work with the private sector, academia and other federal agencies to explore the feasibility and capability of emerging technologies spacecraft and other mission-specific tools to meet NOAA’s mission requirements. AWP was initially demonstrated on the NASA DC-8 within this JV program in October 2023, piggybacking on the NASA EcoDemonstrator mission focused on in-situ sampling of jet aircraft emissions and contrail formation from Everett, Washington. The in-situ sampling resulted in very frequent and rapid aircraft attitude changes which unfortunately degraded AWP data quality. But, during times with level flight and AVAPS dropsonde operations, AWP demonstrated excellent precision (< 2 m/s RMS) with high vertical (< 100 meter) resolution and 2 km spacing between profiles. AWP will be flown again on the NASA LaRC Gulfstream-3 from mid-September to mid-October 2024 out of Hampton, VA to complete the NOAA JV 3-D wind demonstration. Additional AWP flights will occur in early November from southern California during the NASA Active-Passive Profiling Experiment (APEX), focused on underflights of the NASA ER-2 equipped with many atmospheric profiling sensors. This presentation will summarize AWP measurements collected during these two fall 2024 flight campaigns, and how the AWP data compares with AVAPS dropsonde, NOAA weather prediction model, and GOES atmospheric motion vector data.

Kristopher Bedka↗