Astrophysicist

NASA Goddard Space Flight Center - Greenbelt, MD

August 1988 - Present

Currently:

Operations Project Scientist for Hubble Space Telescope

Ground System Scientist for Roman Space Telescope

NIAC Fellow, Artemis-enabled Stellar Imager (AeSI)

Principal Investigator, Stellar Imager (SI) Vision Mission Concept

Lead Scientist for OpTIIX ISS-based technology demonstration mission

Stellar Astrophysics and Space Instrument/Mission Development

Ultraviolet spectroscopy. Chromospheres, transition regions and winds of cool stars. Stellar activity. Model atmospheres and synthetic spectra. Line fluorescence processes. Chemically peculiar stars. Instrument development, in particular development and calibration of UV spectrographs. Long-Baseline Imaging Interferometry.

Carpenter is the lead scientist/architect for a long-term study of the outer atmospheres and winds of stars cooler than the sun, utilizing IUE, HST, ground-based and other space-based facilities. Core HST/GHRS results, based on combined GTO and GO programs, have been published in an ApJ series: ``GHRS Observations of Cool, Low-Gravity Stars. I-V''. He has collaborated in studies of stellar activity/chromospheric heating in Hyades F stars and of the origin of Ba-star abundances anomalies with E. Bohm-Vitense (U. Washington) and shared leadership (with H. Johnson/Univ. of Indiana) of large, international consortium study of carbon stars with HST. He has been involved in a multiple-cycle HST program to determine masses of Cepheid variables, published frequently-cited UV reference spectra for cool stars, obtained first measurements of turbulence and plasma downflows in the chromosphere of a cool giant star, and published a definitive summary of fluorescence in cool giant atmospheres (in collaboration with C. Jordan/Oxford U., England and S. Johansson/U. Lund, Sweden). He has also computed detailed, line-blanketed model atmospheres, including magnetic pressure, for upper main sequence stars to study effect of magnetic-field on structure and emergent spectrum and the degree to which line strength peculiarities in chemically peculiar stars can be explained without recourse to anomalous abundances.

HST Operations Project Scientist

Technology & Missions

Carpenter is currently the Operations Project Scientist for Hubble Space Telescope and provides scientific leadership, advice, guidance, and oversight to the Operations Project Manager and Staff, monitors budgeting activities as related to HST mission scientific requirements and participates in tradeoff decisions, monitors in-orbit performance of flight instruments & other spacecraft systems, provides scientific guidance in the assessment and resolution of spacecraft anomalies, supports the development of future science operations concepts, and oversees current STScI science operations.

Ground System Scientist for Roman Space Telescope

Technology & Missions

Carpenter is the Ground System Scientist for the Roman Space Telescope and supports mission concept and ground system design and implementation efforts via the GSFC Roman Project Science Office.

NIAC Fellow, leading the Artemis-enabled Stellar Imager (AeSI) Concept Study

Technology & Missions

Selected as a NIAC (NASA Innovative Advanced Concepts) Fellow 2024 to develop a mission concept for a lunar-based variant of Stellar Imager called the Artemis-enabled Stellar Imager (AeSI).

GSFC Lead Scientist for OpTIIX

Technology & Missions

Carpenter provides scientific guidance to the JPL/GSFC/JSC/STScI Optical Testbed and Integration on ISS eXperiment (OpTIIX) Team.

Principal Investigator, Stellar Imager (SI) Vision Mission

Technology & Missions

He is the Principal Investigator of the Stellar Imager (SI) Vision Mission Study - a concept for a large, space-based UV-optical interferometer designed to image the surfaces of nearby stars, probe their subsurface layers through asteroseismology (acoustic imaging), and improve our understanding of solar and stellar dynamos and thus our ability to predict solar/stellar activity and its effect on the habitability of planets, planetary climates, and life.

Principal Investigator, Fizeau Interferometer Testbed (FIT)

Technology & Missions

Carpenter led the Fizeau Interferometer Testbed (FIT) experiment, a ground-based laboratory testbed located at GSFC. This testbed developed and tested algorithms for closed-loop control of actuated multi-element (7-20) sparse aperture systems, using feedback from Phase Diversity analysis of the combined beams - a critical technology for future long-baseline Fizeau Interferometers and Sparse Aperture Telescopes.

GHRS Investigation Definition Team Co-I for Science Operations

Technology & Missions

Previously, Carpenter was GHRS (Goddard High Resolution Spectrograph) Investigation Definition Team Co-Investigator for Science Operations and guided GHRS Operations Development, Science Verification/Guaranteed Time Observer science program implementation, and helped ensure the high science productivity of the GHRS when it was installed on HST.

International Astronomical Union

Member of IAU Commission 29 (Stellar Spectra), Organizing Committee - Commission 29, Commission 44 (Space & High Energy Astrophyics), and Commission 54 (Optical & Infrared Interferometry)

1988 - Present

American Astronomical Society

Member.

1977 - Present