Update from the Director

Pat Slane

Merging neutron stars. Once more, I find myself thinking about these energetic events, which represent the prominent formation channel for the highly conductive metal that ceremoniously marks twenty-five years. So, many thanks to our friend GW170817—or, actually, to some more nearby cousin from the past—for helping to seed the celebration of our silver anniversary!

Observing the emission from that first gravitational wave source with an electromagnetic counterpart—detecting the fading glow of the hypernova long after other telescopes had lost sight—is just one of the vast number of Chandra’s spectacular contributions to modern astrophysics. From resolving the hazy X-ray background into a speckled array dominated primarily by black holes to peering through a gravitational lens to peek at supermassive black hole formation at the edge of time, Chandra has continued to do things that no other X-ray observatory can. It is unique, it is powerful, and it is healthy—and it is poised to help continue framing the future of high energy astrophysics for years to come.

The vast discovery space opened by Chandra over the course of twenty-five years is too broad to touch on here, but will be at the core of the 25 Years of Science with Chandra Symposium in Boston this December. Registration and abstract submission are currently open, and you can read more about the symposium in this issue.

Meanwhile, this past year has seen an incredible burst of new and exciting progress with Chandra. Following the resolution of an anomaly and the development of a new operations concept for the HRC early last year, the instrument has carried out over 200 new observing segments. The implementation of processes to enable ACIS to provide radiation-level monitoring for detection of elevated solar particle levels—and subsequent safing of instruments—has performed flawlessly. Chandra images graced everything from the Metro in Washington, DC, to Sphere in Las Vegas. The release of a call for whitepapers on topics for a Chandra Legacy Program resulted in an oversubscription factor of 15, leading to selected programs to study the baryon cycle in nearby galaxies and the detailed structure of a galaxy cluster. And investigations of the Chandra Momentum Unloading Propulsion System have resulted in upcoming relaxation of temperature limits that will bring uninterrupted observing times to 2019 levels over a considerable range of pitch angles. In short, every aspect of the mission has continued successfully, with improvements in multiple areas.

Of course, such successes and innovations are not unique to the past year. The Chandra team and the broader Chandra community have demonstrated a history of unwavering performance over the entire twenty-five years of operation. As nearly everyone reading this Newsletter understands, it was thus completely unanticipated when, last fall, NASA decided to target Chandra for very significant budget reductions. The details of this process have been discussed broadly elsewhere, with significant concern expressed by the community and summarized by the Chandra Users' Committee. The mission, along with Hubble, was directed to go through an “Operating Paradigm Change Review” to investigate potential models for reduced modes of operation at lower cost levels. The results of that process—which included scenarios for a lower-cost Chandra mission with drastically reduced capabilities—are still unfolding at the time of this writing. We remain anxiously hopeful for the continuation of this Great Observatory at full capabilities.

A total solar eclipse, viewing the shimmering Aurora Borealis, my first Bruce Springsteen concert—all literally unforgettable experiences. But the nighttime launch of STS-93 to deliver Chandra to orbit twenty-five years ago? A life-changing vision for me—and some of you—and the beginning of a revolution in high energy astrophysics.

See you in Boston in December!