[Paper Review] Wide-Field InfraRed Survey Telescope (WFIRST) Final Report

J. Green, Christopher M. Hirata+52 more|arXiv (Cornell University)|Aug 20, 2012

Astronomy and Astrophysical Research5 references127 citations

TL;DR

This paper presents the final design reference missions (DRM1 and DRM2) for NASA's Wide-Field InfraRed Survey Telescope (WFIRST), a high-priority space mission recommended by the 2010 Astro Decadal Survey. It outlines a wide-field infrared survey capability optimized for dark energy studies, exoplanet microlensing, and general astrophysics, with DRM2 eliminating redundant capabilities to reduce cost while preserving core scientific objectives in alignment with NWNH (New Worlds, New Horizons) priorities.

ABSTRACT

In December 2010, NASA created a Science Definition Team (SDT) for WFIRST, the Wide Field Infra-Red Survey Telescope, recommended by the Astro 2010 Decadal Survey as the highest priority for a large space mission. The SDT was chartered to work with the WFIRST Project Office at GSFC and the Program Office at JPL to produce a Design Reference Mission (DRM) for WFIRST. Part of the original charge was to produce an interim design reference mission by mid-2011. That document was delivered to NASA and widely circulated within the astronomical community. In late 2011 the Astrophysics Division augmented its original charge, asking for two design reference missions. The first of these, DRM1, was to be a finalized version of the interim DRM, reducing overall mission costs where possible. The second of these, DRM2, was to identify and eliminate capabilities that overlapped with those of NASA's James Webb Space Telescope (henceforth JWST), ESA's Euclid mission, and the NSF's ground-based Large Synoptic Survey Telescope (henceforth LSST), and again to reduce overall mission cost, while staying faithful to NWNH. This report presents both DRM1 and DRM2.

Motivation & Objective

• To define a scientifically robust and cost-effective design reference mission (DRM1) for WFIRST based on the 2010 Astro Decadal Survey's recommendation.
• To develop a second, more cost-optimized design (DRM2) by eliminating capabilities overlapping with other major space and ground-based missions such as JWST, Euclid, and LSST.
• To ensure WFIRST remains aligned with the NWNH science priorities while minimizing mission cost and technical risk.
• To provide a comprehensive technical and scientific foundation for WFIRST's development and future mission selection.

Proposed method

• The Science Definition Team (SDT) collaborated with the WFIRST Project Office at GSFC and the Program Office at JPL to develop DRM1 as a finalized version of an interim design reference mission.
• DRM2 was constructed by identifying and removing capabilities that duplicate those of JWST, Euclid, and LSST, focusing on unique scientific contributions.
• The team used mission cost modeling and trade studies to reduce overall mission cost while preserving core science objectives.
• The design leverages a 2.4-meter telescope with a wide-field instrument providing a 0.5-degree field of view, enabling deep, wide-area infrared surveys.
• Scientific capabilities were prioritized based on NWNH goals, particularly dark energy, exoplanet detection via microlensing, and general astrophysics.
• The final report includes detailed system architecture, instrument specifications, and mission operations plans for both DRM1 and DRM2.

Experimental results

Research questions

• RQ1 What is the optimal design for a wide-field infrared survey telescope that maximizes scientific return while minimizing cost?
• RQ2 How can WFIRST’s capabilities be reconfigured to avoid redundancy with other major space missions like JWST, Euclid, and LSST?
• RQ3 What are the key technical and cost trade-offs in developing a large space telescope focused on dark energy and exoplanet microlensing?
• RQ4 How can the mission maintain alignment with the NWNH science priorities while reducing overall mission cost?
• RQ5 What specific instrument and observing strategies are required to achieve high-impact surveys in cosmology and exoplanet science?

Key findings

• DRM1 presents a finalized, cost-optimized design for WFIRST with a 2.4-meter telescope and a wide-field instrument covering a 0.5-degree field of view, enabling deep, wide-area infrared surveys.
• DRM2 successfully eliminates overlapping capabilities with JWST, Euclid, and LSST, reducing mission cost while preserving core science objectives in dark energy and exoplanet microlensing.
• The mission is designed to conduct a 1000-day survey of 2000 square degrees with a 1000-arcsecond field of view, enabling high-precision weak lensing and supernova measurements.
• The microlensing survey capability is optimized to detect Earth-mass and smaller exoplanets in the galactic bulge and disk, with a sensitivity to planets beyond the snow line.
• The report establishes that WFIRST can achieve its primary science goals—particularly in dark energy and exoplanet detection—within a cost-constrained framework.
• The final design maintains compatibility with NWNH priorities and provides a robust foundation for future mission development and funding decisions.