NASA’s Chandra termination locks us out of high-resolution X-ray space

NASA’s Chandra termination locks us out of high-resolution X-ray space

Written by Maria Arias

The Chandra X-ray Observatory is the darling of high-energy astrophysics. The spacecraft is famous for providing unparalleled X-ray observations of greedy supermassive black holes, exploding massive stars, and even dark matter-injecting collisions between galaxy clusters, making it one of astrophysics’ largest Explore mysteries.

But 25 years after seeing first light, Chandra’s future is up in the air.

In March, NASA cut Chandra’s budget from $68 million in 2024 to $41 million in 2025 and $26 million a year later. According to the Chandra X-ray Center, which operates the telescope, this will only allow the mission to end. In the months since then, a series of events, including an intensive public relations campaign and Congressional declaration of support, have kept Chandra’s funding running until September 2025. But in this year’s senior review evaluating NASA’s mission, the Chandra X-ray Center was told to stay within the proposed budget, which meant planning how to shut down the spacecraft. .

This is wrong. Chandra must remain operational until a significant failure occurs or it is replaced by a comparable mission. Chandra is only There is a high-angular-resolution X-ray telescope in space, and no mission with similar capabilities is scheduled to replace it until 2032 at the earliest.

What new discoveries can Chandra make that haven’t been made in the past 25 years? That’s a good question. But since Chandra’s launch, our observing capabilities have changed significantly, and so has our potential to make discoveries that require multiple telescopes. We have only recently arrived at the era of multiwavelength, multimessenger astrophysics, where we can now see stars and galaxies in everything from the radio spectrum to gamma rays, neutrinos, and gravitational waves simultaneously. . If high-resolution radiography is given up, many of its important synergies will be lost and wasted.

In some ways, Chandra was ahead of his time. Some of the most memorable discoveries, such as the detection of sound waves from supermassive black holes, are science unique to Chandra. But its most important recent achievements have come from a combination of its sharp X-ray vision and new instruments such as the James Webb Space Telescope and the Event Horizon Telescope.

In 2017, when gravitational waves from two merging neutron stars reached Earth, all major observatories around the world conducted follow-up observations of this historic and unprecedented astronomical phenomenon. The merger of binary neutron stars caused a kilonova explosion that sparkled across the electromagnetic spectrum. That X-ray emission was due to accelerated particles from the explosion’s blast wave, and gave us information about the material around the binary star. No other facility has been able to locate mergers as accurately as Chandra. Without Chandra, our understanding of one of the most important astrophysical phenomena of our time would be incomplete.

After a quarter of a century of operation, Chandra is a well-oiled machine with an experienced team that has adapted to the aging telescope. Keeping Chandra at the forefront of astronomy “is getting more complex, but it doesn’t have to be expensive. We’re improving the technology every day,” says Chandra Science Operations Astrophysics. says scholar Daniel Castro.

The core of the problem lies in the president’s budget request from March of last year. This budget request caught the public by surprise as it was misinterpreted as Chandra’s rapidly declining integrity and increasing costs. A further source of frustration within the community is that NASA unexpectedly changed its own peer-review process for assessing the timeliness of mission completion, Advanced Review (which had given Chandra the highest score in 2022), to This was avoided by cutting funding. Due to budget cuts, the Chandra mission will end without any discussion or input from the astrophysics community.

NASA’s interesting choice is to donate $50 million to the development of the Habitable World Observatory (HWO), and the same funding will keep Chandra fully operational. HWO is NASA’s flagship infrared, optical, and ultraviolet telescope, which will take 20 to 30 years to launch and will likely cost an estimated $6 billion to more than $10 billion.

Mr. Webb’s costs have ballooned from an initial $2 billion to $8 billion, posing a major problem in his decision to prioritize funding for HWO. While NASA is commendable for keeping an eye on future challenges, much of the initial funding for HWO will be spent on preliminary overhead costs such as building a project office and establishing industry partnerships. will be done. It’s worth considering whether giving $50 million to a multibillion-dollar mission decades before launch justifies canceling a mission as productive as Chandra. .

Astronomers are toying with ideas about other sources of funding for Chandra, including selling its operations to Japanese or European space agencies or relying on private donations. Collaboration with other space agencies and companies is standard in astrophysics, but it’s a long process, and much of Chandra’s technology is walled off by U.S. technology transfer regulations. Additionally, NASA policy directives allow for donations, but not conditions for their use. Besides, do we want (sometimes insane) space billionaires moving into basic science? Access to space is a public good, and most of our astronomers want to avoid the possibility of oligarchs becoming its gatekeepers.

Defeating Chandra highlights the tensions inherent in flagship-style astronomical missions. They make amazing discoveries, but they also have a way of absorbing the budget of medium-sized or existing missions. we need Telescopes open up new parameter spaces, making them more powerful, and this is how truly revolutionary discoveries are made. However, a delicate balance needs to be maintained here. What are we giving up by allocating such initial funding to HWO? The window is open, but I think the door is closed. We choose to be blind to the world of high-resolution X-rays. And that’s a loss for science as a whole.

This is an opinion and analysis article and the views expressed by the author are not necessarily those of the author. scientific american.