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Anh N Nguyen

Publications and source records attributed to Anh N Nguyen.

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2025

Abundant Ammonia and Nitrogen-Rich Soluble Organic Matter in Samples From Asteroid (101955) Bennu

Organic matter in meteorites reveals clues about early Solar System chemistry and the origin of molecules important to life, but terrestrial exposure complicates interpretation. Samples returned from the B-type asteroid Bennu by the Origins, Spectral Interpretation, Resource Identifcation, and Security–Regolith Explorer mission enabled us to study pristine carbonaceous astromaterial without uncontrolled exposure to Earth’s biosphere. Here we show that Bennu samples are volatile rich, with more carbon, nitrogen and ammonia than samples from asteroid Ryugu and most meteorites. Nitrogen-15 isotopic enrichments indicate that ammonia and other N-containing soluble molecules formed in a cold molecular cloud or the outer protoplanetary disk. We detected amino acids (including 14 of the 20 used in terrestrial biology), amines, formaldehyde, carboxylic acids, polycyclic aromatic hydrocarbons and N-heterocycles (including all fve nucleobases found in DNA and RNA), along with ~10,000 N-bearing chemical species. All chiral non-protein amino acids were racemic or nearly so, implying that terrestrial life’s left-handed chirality may not be due to bias in prebiotic molecules delivered by impacts. The relative abundances of amino acids and other soluble organics suggest formation and alteration by low-temperature reactions, possibly in NH3-rich fuids. Bennu’s parent asteroid developed in or accreted ices from a reservoir in the outer Solar System where ammonia ice was stable.

Daniel P Glavin↗
NASA NTRS2024

Ensuring Safety of Government Personnel During Suborbital Spaceflight

The NASA Suborbital Crew (SubC) project is focused on enabling flights by NASA civil servants, such as scientists and engineers conducting research, on suborbital vehicles. A broader goal is ensuring that commercial human spaceflight is both viable and safe. Within the Commercial Crew Program (CCP), the SubC project is exploring game-changing methods to perform safety assessments to enable NASA personnel to fly on suborbital missions. Commercial suborbital space flight capabilities are anticipated to be more accessible, affordable, and available than missions to the International Space Station and could provide additional opportunities for testing and qualification of space flight hardware, human-tended microgravity research, and further cutting-edge research enabled by the space environment. Although NASA currently permits human tended suborbital payloads for non-civil servants under auspices of NASA’s Flight Opportunities Program, the SubC effort will enable civil servant scientists, researchers, and even engineers to accompany their experiments and tests into the space microgravity environment. Figure 1 illustrates how the SubC program complements other microgravity experimental platforms. The targeted scope for SubC includes end-to-end suborbital capabilities reaching ~80km with several minutes of sustained microgravity (Table 1). The NASA SubC project office is working with the Federal Aviation Administration’s Office of Commercial Space Transportation (FAA-AST) and the commercial suborbital space transportation industry to develop an efficient and holistic approach to a safety review and eventual government participation in suborbital flight. The current FAA certification process for suborbital launches is congressionally mandated to only consider public safety. NASA is responsible for understanding the risks to its employees should they fly on a commercially available suborbital flight. The SubC project is employing a Safety Case approach, applied to commercial suborbital providers, which is not a traditional certification process as was used for the SpaceX Dragon and Boeing Starliner vehicles. Rather, it is an assessment using elements of NASA’s Risk-Informed Safety Case and the Armstrong Flight Research Center’s Airworthiness Assessment process.

Elizabeth C Blome↗