WASHINGTON — NASA and the Japanese space agency JAXA have decided to keep using a tool on an X-ray astronomy satellite in its current state for at least the next 18 months, even though there is a problem with one of its instruments.
JAXA launched the X-ray Imaging and Spectroscopy Mission (XRISM) in September 2023 with instruments developed in collaboration with NASA. The spacecraft has just begun its primary science mission. XRISM is equipped with two instruments for conducting X-ray astronomy.
In January, scientists involved in the project reported that XRISM was functioning well, except for a gate valve, which is part of the Dewar on its imaging instrument called Resolve, that failed to open. This aperture door, made of beryllium, can still function with the door shut, although it does block some X-rays at lower energies.Efforts were being made to try opening the gate valve, but Mark Clampin, director of NASA’s astrophysics division, stated at a May 7 meeting that these efforts will be put on hold for the next 18 months.
At the meeting, he explained, “We have decided to pursue the scientific program for the next 18 months. It's still producing valuable scientific data even with the valve stuck closed. We believe it's best to continue collecting data over the next 18 months before attempting to dislodge the gate valve.”
The valve was supposed to be moved out of the way using two non-explosive actuators, but Clampin mentioned that there may be a snag on a harness attached to one of the non-explosive actuators, preventing the valve from moving. This is due to the challenge of dealing with the harness at extreme cold temperatures. He stated that the current plan is to focus on gathering scientific data for the next 18 months before returning to the issue of the gate valve.
He also mentioned the difficulties related to working with the harness at cryogenic temperatures and the proposed solutions, involving managing temperatures within the instrument and possibly shaking the harness to loosen it. He emphasized that the approach with the lowest risk is to continue with the scientific work and address the gate valve later.
Clampin briefly addressed budget challenges in his presentation, including proposals to make changes to the operations of the Chandra X-Ray Observatory and Hubble Space Telescope to reduce their costs. He indicated that these efforts are still ongoing with no major updates on their progress.
NSF astronomy budget challenges
During the meeting, Clampin also briefly discussed budget issues, including proposals to review operations of the Chandra X-Ray Observatory and Hubble Space Telescope in order to cut costs. He mentioned that these efforts are still in progress without any significant updates on their advancement. NASA is not the only agency facing challenges in funding major astronomy programs. In the same board meeting, R. Chris Smith, interim director of the astronomical sciences division at the National Science Foundation, mentioned that his agency had recently decided to halt work on a major ground-based astrophysical project. This project, called CMB-S4, had planned to set up an observatory at the South Pole to study the cosmic microwave background, which provides insight into the early universe, dark matter, and dark energy. It was a top priority in both the Astro2020 decadal survey and a separate review of priorities in particle physics.
Smith stated at the board meeting that NSF had chosen not to progress CMB-S4 to the next phase of development, known as the Major Facility Design Stage, currently. He mentioned the need for NSF to invest in overall infrastructure at the South Pole.
“The agency needs to prioritize the renewal of the essential infrastructure at the South Pole,” he said. He indicated that this work would support a wide range of scientific research conducted at the South Pole, not just astrophysics. He later mentioned that CMB-S4 could move forward at a later, unspecified date.
One reason for this decision is the agency's budget. In fiscal year 2024, NSF requested $11.3 billion but received less than $9.1 billion. Smith mentioned that NSF is still developing an operating plan for 2024, with no details yet on how it would impact work in its various divisions, including astronomical sciences.
This is also influencing how the NSF approaches the top groundbased astronomy priority in Astro2020, which is support for the U.S. Extremely Large Telescope (US-ELT) program. This would provide funding for two large telescopes currently in development, the Thirty Meter Telescope (TMT) and Giant Magellan Telescope (GMT). NSF would partially finance both telescopes and receive a share of observing time for the broader astrophysics community.
In March, the NSF announced that the National Science Board had recommended supporting only one of the two telescopes, with a cost limit of $1.6 billion. This was at the same time as the report accompanying the final fiscal year 2024 appropriations bill included language that “strongly encourages” the NSF to support both US-ELT telescopes.
Smith mentioned at the board meeting that the NSF, during a May 2 meeting, officially initiated the process to decide between the two large telescope projects. The director of NSF, Sethuraman Panchanathan, formally instructed the agency to begin an external review that will provide him with advice on whether to support either telescope.
This review will assess the progress GMT and TMT have made since their preliminary design reviews and how they are managing various risks. It will also examine how proceeding with either telescope would impact overall NSF resources.
Smith mentioned that the review is set to be completed by September, but did not indicate when NSF would formally select one of the telescope projects for agency support.
NASA and the Japanese space agency JAXA plan to keep operating an instrument on an X-ray astronomy satellite as-is for at least the next year and a half despite an issue affecting one of its instruments.
Smith said that review is scheduled to be completed by September, but didn’t indicate when NSF would formally select one of the telescope projects for agency support.
