Keith Warfield

Exo-C: a Probe-Scale Space Mission to Directly Image and Spectroscopically Characterize Exoplanetary Systems Using an Internal Coronagraph

“Exo-C” is NASA’s first community study of a modest aperture space telescope designed for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discover previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. At the study conclusion in 2015, NASA will evaluate it for potential development at the end of this decade.

Aerospace Concurrent Engineering Design Teams: Current State, Next Steps and a Vision for the Future

Over the past sixteen years, government aerospace agencies and aerospace industry have developed and evolved operational concurrent design teams to create novel spaceflight mission concepts and designs. These capabilities and teams, however, have evolved largely independently. In today’s environment of increasingly complex missions with limited budgets it is becoming readily apparent that both implementing organizations and today’s concurrent engineering teams will need to interact more often than they have in the past. This will require significant changes in the current state of practice. This paper documents the findings from a concurrent engineering workshop held in August 2010 to identify the key near term improvement areas for concurrent engineering capabilities and challenges to the long-term advancement of concurrent engineering practice. The paper concludes with a discussion of a proposed vision for the evolution of these teams over the next decade.

Overview of the 4m baseline architecture concept of the habitable exoplanet imaging mission (HabEx) study

The Habitable Exoplanet Imaging Mission (HabEx) Study is one of four studies sponsored by NASA for consideration by the 2020 Decadal Survey Committee as a potential flagship astrophysics mission. A primary science directive of HabEx would be to image and characterize potential habitable exoplanets around nearby stars. As such, the baseline design of the HabEx observatory includes two complimentary starlight suppression systems that reveal the reflected light from the exoplanet – an internal coronagraph instrument, and an external, formation-flying starshade occulter. In addition, two general astrophysics instruments are baselined: a high-resolution ultraviolet spectrograph, and an ultraviolet, visible, and near-infrared (UV/Vis/NIR), multi-purpose, wide-field imaging camera and spectrograph. In this paper, we present the baseline architecture concept for a 4m HabEx telescope, including key requirements and a description of the mission and payload designs.

Technology maturity for the habitable-zone exoplanet imaging observatory (HabEx) concept

HabEx Architecture A is a 4m unobscured telescope mission concept optimized for direct imaging and spectroscopy of potentially habitable exoplanets, and also enables a wide range of general astrophysics science. The exoplanet detection and characterization drives the enabling core technologies. A hybrid starlight suppression approach of a starshade and coronagraph diversifies technology maturation risk. In this paper we assess these exoplanet-driven technologies, including elements of coronagraphs, starshades, mirrors, jitter mitigation, wavefront control, and detectors. By utilizing high technology readiness solutions where feasible, and identifying required technology development that can begin early, HabEx will be well positioned for assessment by the community in 2020 Astrophysics Decadal Survey.

HabEx ultraviolet spectrograph design and DRM

We present an update to our paper from last year on the design and capabilities of the Ultraviolet Spectrograph (UVS) instrument on the Habitable Exoplanet Observatory (HabEx) concept. The design has been matured to be both more compact and serviceable while delivering all the required capabilities that the original Science Traceability Matrix (STM) demanded. Since last year the project has begun design considerations for a second Architecture for the overall mission, and we present design changes that optimize the performance of the instrument when combined with that Optical Telescope Assembly (OTA). Results of a start at a community driven Design Reference Mission (DRM) are also included to illustrate the anticipated performance of the instrument.

The Habitable Exoplanet Observatory (HabEx)

The Habitable-Exoplanet Observatory (HabEx) is a candidate flagship mission being studied by NASA and the astrophysics community in preparation of the 2020 Decadal Survey. The first HabEx mission concept that has been studied is a large (~4m) diffraction-limited optical space telescope, providing unprecedented resolution and contrast in the optical, with extensions into the near ulttraviolet and near infrared domains. We report here on our team’s efforts in defining a scientifically compelling HabEx mission that is technologically executable, affordable within NASA’s expected budgetary envelope, and timely for the next decade. We also briefly discuss our plans to explore less ambitious, descoped missions relative to the primary mission architecture discussed here.

The habitable exoplanet imaging mission (HabEx): science goals and projected capabilities (Conference Presentation)

The Habitable-Exoplanet Imaging Mission (HabEx) is a candidate flagship mission being studied by NASA and the astrophysics community in preparation of the 2020 Decadal Survey. The HabEx mission concept is a large (~4 to 6.5m) diffraction-limited optical space telescope, providing unprecedented resolution and contrast in the optical, with extensions into the near UV and near infrared domains. The primary goal of HabEx is to answer fundamental questions in exoplanet science, searching for and characterizing potentially habitable worlds, providing the first complete “family portraits” of planets around our nearest Sun-like neighbors and placing the solar system in the context of a diverse set of exoplanets. At the same time, HabEx will enable a broad range of Galactic, extragalactic, and solar system astrophysics, from resolved stellar population studies that inform the stellar formation history of nearby galaxies, to characterizing the life cycle of baryons as they flow in and out of galaxies, to detailed studies of bodies in our own solar system. We report here on our team’s efforts in defining a scientifically compelling HabEx mission that is technologically executable, affordable within NASA’s expected budgetary envelope, and timely for the next decade. In particular, we present architectures trade study results, quantify technical requirements and predict scientific yield for a small number of design reference missions, all with broad capabilities in both exoplanet science and cosmic origins science. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

HabEx yield modeling with for systems engineering (Conference Presentation)

We present yield modeling results for the HabEx concept study using EXOSIMS. EXOSIMS (Exoplanet Open-Source Imaging Mission Simulator) provides a parametric estimate of science yield of mission concepts using contrast curves from physics-based diffraction model codes and Monte Carlo simulations of design reference missions using realistic observing constraints. Two baseline architecture configurations and two extended configurations are compared. We compare a configuration with a coronagraph to a configuration with a starshade for both detection and spectral characterization. The input parameters, including astrophysical assumptions, are detailed. We show sensitivity to key design parameters around design space local to the point designs. The yield results provide an analysis of the relative performance of telescope and instrument design that enable system engineering decisions.

Habitable exoplanet imaging mission (HabEx): initial flight system design

The Habitable Exoplanet Imaging Mission (HabEx) is a concept for a mission to directly image planetary systems around Sun-like stars and to perform general astrophysics investigations being studied as part of a number of mission concepts for the upcoming 2020 Astrophysics Decadal Survey. HabEx would help assess the prevalence of habitable planets in our galaxy, searching in particular for potential biosignatures in the atmospheres of planets in habitable zones. More generally, HabEx would image our neighboring solar systems and characterize the variety of planets that inhabits them. Its direct imaging capability would also enable the mission to study the structure and evolution of debris disks around nearby stars, and their dynamical interaction with planets. Additionally, it will explore a number of more general astrophysics phenomena in our solar system, galaxy, and beyond, in the UV through NIR range. The exoplanet science goals lead to a mission concept with requirements for high contrast imaging and the continuous spectral coverage. The baseline for HabEx is a 4-meter diameter off-axis telescope designed to both search for habitable planets and perform general astrophysics observations, possibly combined with a starshade. In this paper, the initial flight system design for both the telescope and the starshade are presented, focusing on the key and driving requirements and subsystems, as well as the trajectory and station keeping and formation flying technique. Furthermore, some of the initial design trades undergone are described, as well as the key challenges and enablers. Finally, some of the future design and architecture trades to be performed within the flight systems as part of the continuing effort in the HabEx study are discussed.

An analysis of technology gaps and priorities in support of probe-scale coronagraph and starshade missions

This paper provides a survey of the state-of-the-art in coronagraph and starshade technologies and highlights areas where advances are needed to enable future NASA exoplanet missions. An analysis is provided of the remaining technology gaps and the relative priorities of technology investments leading to a mission that could follow JWST. This work is being conducted in support of NASAs Astrophysics Division and the NASA Exoplanet Exploration Program (ExEP), who are in the process of assessing options for future missions. ExEP has funded Science and Technology Definition Teams to study coronagraphs and starshade mission concepts having a lifecycle cost cap of less than