One of NASA’s biggest upcoming astrophysics missions has been stopped in its tracks, and the project’s leader is blaming mismanagement at the space agency caused by last year’s budget confusion.
AXIS, the Advanced X-ray Imaging Satellite, was one of two concepts selected for detailed design studies in NASA’s Astrophysics Probe Explorer program, competing alongside the far-infrared observatory concept PRIMA. AXIS could have replaced NASA’s aging Chandra observatory, which has remained a powerhouse of X-ray astronomy since 1999, but the project is coming to an abrupt halt.
An internal email sent on March 9 from AXIS Principal Investigator Christopher Reynolds informed the mission’s international team members that NASA Headquarters has ruled the program ineligible for selection, ending the project’s run before its concept study could undergo full technical review.
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“NASA’s decision was NOT a judgment of the importance of AXIS science,” Reynolds said in the email, which was posted to social media. He said that AXIS’ removal from eligibility was tied to disruptions at NASA’s Goddard Space Flight Center (GSFC) in Maryland, which managed the mission during a period of sweeping workforce losses and operational instability throughout 2025.
“The mission formulation process was critically compromised by the seismic shifts occurring in NASA and the Federal government,” Reynolds wrote.
One major setback was brought on by the early retirement of Will Zhang, a scientist that NASA describes as a “mirror-making whiz” for space telescopes.
“The key enabling technology for AXIS is these single-crystal silicon mirror assemblies, pioneered by Will Zhang at GSFC,” a Goddard scientist familiar with the matter, but not authorized to speak on behalf of NASA, told Space.com. “Will was always intending to retire soon but he took the DRP.”
“One major goal for Phase A for AXIS was to get at least one of these mirror assemblies built to prove it could be done. They got none built,” the scientist said. “It seemed like every week there was an announcement that someone was leaving the AXIS team due to retirement or finding a different job, all because of the uncertainty with NASA funding and the truly chaotic environment at GSFC.”
The project lost more than 20 GSFC personnel with key expertise as a result of NASA’s Deferred Resignation Program (DRP) and reorganizations to align with the 2026 presidential budget request, according to Reynolds’ email, and faced further complications caused by the government shutdown last year.
“Work was halted for almost seven weeks when the core GSFC AXIS study team, dominated by NASA civil servants, was furloughed,” Reynolds said. NASA later extended the Concept Study Report deadline, but Reynolds wrote that the extension was “inadequate compensation for the disruption and lost time” to address cost and schedule adjustments that had already been identified.
According to the email, Goddard leadership ultimately gave AXIS managers a choice: submit a Concept Study Report with a non-compliant cost and schedule, or don’t submit one at all. NASA also apparently rejected the AXIS’ team’s appeal to bring the design within compliance during discussions normally held during the review process, calling that option “unacceptable,” Reynolds said.
Another Goddard scientist not authorized to speak for NASA, speaking on the condition of anonymity, told Space.com that’s not how it’s normally done. “It is not at all unusual for a mission concept to be off in budget and launch date after their first pass — the first run-through you ask for everything you can possibly imagine, and then you start scoping back into what is more reasonable while still fulfilling the mission requirements,” the scientist said. “The 10% they were off by is not bad at all for a first pass, but they did not have time to get additional quotes to bring it down.”
They said the blame sits with NASA management.
“Internally, the general consensus is that this is 100% down to Goddard leadership mismanaging this … this has absolutely nothing to do with the AXIS team, the merit of AXIS as a concept in general, and especially not the Goddard scientists, engineers, and project managers who have put their everything into this mission and were held back by management at every step of the way.”
NASA said the decision followed the agency’s standard science mission selection process, which includes several checkpoints at which mission concepts are evaluated for compliance with established requirements.
“NASA has confirmed the AXIS (Advanced X-ray Imaging Satellite) Probe concept was not compliant with the 2023 Astrophysics Probe Explorer Announcement of Opportunity,” an agency official told Space.com in an email, adding that more opportunities for the X-ray astrophysics community will be announced in the coming weeks.
“I am, quite frankly, livid that AXIS ultimately fell victim to the programmatic chaos of 2025,” Reynolds told the AXIS team, arguing that the decision did not reflect the scientific importance of the mission.
AXIS was not necessarily the front runner against PRIMA, the X-ray space telescope’s competitor in the Astrophysics Probe program, though. “AXIS was always the riskier of the proposed X-ray probes and people in the community were generally surprised they selected AXIS for Phase A,” one of the Goddard scientists said. “Some folks believe it was selected because it was the most Chandra-like, and Chandra is old [and] could use replacing.”
Reynolds closed his message by wishing “a smooth and speedy path to selection and flight” to PRIMA, which remains under consideration. He also noted that other X-ray astronomy projects, like SMEX and MidEX, can benefit from the research already accomplished by the AXIS team.
