NASA’s astrophysics program has an outstanding, decades-long track record of scientific achievement and public engagement. From the Hubble Space Telescope, arguably the greatest space science mission of all time, to the transformational Kepler planet-hunting telescope, NASA’s astrophysics missions have rewritten textbooks and inspired millions. The announcement in President Donald J. Trump’s fiscal year 2019 budget request for NASA to cancel the Wide Field Infrared Survey Telescope (WFIRST) and reduce the astrophysics division budget by 12 percent compared to its FY 2017 budget request is truly puzzling.

The WFIRST mission was the top priority of the rigorous community consensus decadal survey process in 2010 and is the space astrophysics cornerstone in the 2020s for addressing two exciting fields: dark energy and exoplanets. The 2.4-meter diameter WFIRST telescope will deeply embed space astrophysics in the Big Data era, with its near-infrared camera having over 100 times larger field of view than Hubble, accomplishing precision measurements that no other telescope can perform. It also lays the technological foundations for future, more ambitious missions aiming to directly image Earth-like exoplanets around nearby stars.

The long-term picture that the WFIRST cancellation and budget reduction presents for the future of NASA’s astrophysics program is troubling. Figure 1 shows the astrophysics division’s budget history back to FY 2004, along with projections of prospective out-year budget profiles that were to form the basis for the 2020 astronomy and astrophysics decadal survey prioritizations. This projected out-year budget bleeds nearly $1 billion during the next five years, $2 billion to $3 billion over the next decade, and squashes any realistic hope of executing a balanced program at the frontiers of astrophysical research. Despite performing world-class science that captures the imaginations of people around the globe, it is stunning to see that the astrophysics funding is projected to be below its budget from 15 years ago, as though it were a dying field of inquiry with no discoveries left to make. Nothing could be further from the truth!

If the annual budget of the astrophysics division had increases this decade like the other Science Mission Directorate divisions, it would be at least in the $1.6 billion to $1.8 billion range. This is the level needed to support a balanced program of large, medium and small missions carrying out the priorities of the National Academies’ next decadal survey. President Trump’s FY 2019 budget request goes in the reverse direction and will undermine U.S. leadership in astrophysics during the 2020s and beyond.

As shown numerous times by NASA officials at town halls and advisory committee meetings, the annual astrophysics budget at its current level of $1.35 billion – a level that has been flat for several years and is slightly below its historic budgetary levels from FY 2004-2008 – can accommodate the WFIRST mission’s estimated cost profile and be ready for launch by the mid-2020s. WFIRST has vigorous community support, with more than 50 poster presentations and multiple town halls at the most recent meeting of the American Astronomical Society. The AAS has issued a strong statement of support for WFIRST and NASA’s astrophysics program. The astronomical community has never espoused that its most compelling science can be accomplished through a single mission. In fact, the main message over the past several years has been the growing importance of “multi-messenger astronomy,” where understanding the physics of the universe and the phenomena within it require information from across entire electro-magnetic spectrum and now including gravitational waves. WFIRST is a critical piece of the multi-messenger puzzle for a broad suite of science investigations.

The hardest thing to do in programmatic planning is to match content to budget, especially for large, complex missions. It is normal at this early stage of project implementation – in the midst of the WFIRST system requirements review – for the agency to assess lifecycle cost estimates and compare them to the available budget. NASA has been going the extra mile in working with the National Academies, including establishing the WFIRST Independent External Technical/Management/Cost Review, to assess the mission development plans and alignment with the scientific priorities of the 2010 decadal survey in astronomy and astrophysics, and to do so within an acceptable cost profile during the next 7 to 8 years. Even at a targeted lifecycle cost of $3.2 billion, WFIRST would be only a third of the lifecycle cost of the James Webb Space Telescope, the top large astrophysics mission priority from the 2001 decadal survey, expected to launch next year. WFIRST is an appropriate scale of large mission to contemplate at this time. Aside from the critical scientific and technological contributions, it seems that those who decided to cancel WFIRST are also overlooking the important factors of inter-agency and international cooperation and significant taxpayer investment already made in the telescope structure inherited from the National Reconnaissance Office.

Congress needs to restore the WFIRST mission to NASA’s portfolio, to avoid the catastrophe of a “lost decade” and atrophying U.S. leadership in some of the world’s most exciting scientific fields. The best path would be to do so with a strong statement in the final FY 2018 appropriations.

Jon A. Morse is former director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters (2007-2011), and is currently the Chief Executive Officer of the nonprofit BoldlyGo Institute and a Research Associate in the Solar, Stellar, and Planetary Sciences Division at the Harvard-Smithsonian Center for Astrophysics.