SEATTLE — While the partners in the International Space Station have agreed to operate the station through at least the late 2020s, the extended use of the station still faces technical and budgetary challenges.

During a panel session at the International Space Station Research and Development Conference Aug. 3, representatives of NASA and its three Western partners — Canada, Europe and Japan — hailed the confirmation of plans to extend space station operations through 2030. Canada was the last of the four to confirm that extension, doing so in March.

“Our plan is that we’re going to go to the end of the decade,” said Joel Montalbano, NASA ISS program manager. “We’re not going to slow down and slide into the end of the decade. We’re running full steam to the end of 2030.”

The mood was far different from the same conference a year earlier, where the start of the meeting coincided with comments by the head of Roscosmos, Yuri Borisov, that suggested that Russia might exit the partnership as soon as 2024. He and other Russian officials later softened those comments, and in April Roscosmos announced it had committed to ISS operations to 2028.

Montalbano said the extension to 2028, and not 2030, was linked to Roscosmos’ planning cycles. “Roscosmos works in four-year increments, and the last one was 2024,” he said. “As we get closer to 2028, we’ll be working together with Roscosmos and all the international partners to see what makes sense.”

The message that space agency officials and others at the conference was that the ISS was hitting its stride as a research platform. Frank De Winne, ISS program manager at the European Space Agency, said on the panel that a major step in enabling that usage was adding a fourth crew member to the U.S. operating segment, which includes Canada, Europe and Japan. That was possible once SpaceX’s Crew Dragon started crew rotation missions in 2020, ending reliance on Soyuz.

“The bottleneck was crew time,” he said. “Stepping up to this fourth crew member doubled, or more than doubled, the amount of crew time that we could have on board the space station. That really helped us a lot.”

However, in a separate talk at the conference Aug. 1, John Mulholland, Boeing’s vice president and program manager for the ISS, said there are still pressures on ISS operations. “There is a huge backlog of R&D. We should look to maximize our ISS research and meet the growing demand,” he said. “The marginal cost of these investments will provide an overwhelming increase in our science returns.”

While station operations are relatively mature, he said the ISS program needed at least flat, if not slightly increased, funding over the decade amid broader pressures on NASA’s budget. “Right now, the ISS is budgeted for perfection. The vast majority of the time, that is exactly what we see,” he said. “Robustness in funding ensures science throughput even if we have issues on a particular flight.”

Besides support for research on the station, Mulholland said the agency needed money to build a deorbit vehicle. The agency requested $180 million for the vehicle, which will assist in a safe deorbit of the station at the end of its life, in its fiscal year 2024 budget request, and projected spending up to $1 billion on it over its development.

“It must come with new funding or it will significantly impact the ability of ISS sustainment and research utilization,” he said.

He also advocated for upgrades for one of the station’s biggest experiments, the Alpha Magnetic Spectrometer (AMS). That upgrade will “double the science capability” of the instrument, installed on the station’s exterior in 2011 to study cosmic radiation, but will require what he described as “almost an entire cargo flight” to get the equipment to the station.

Investments like that in the ISS will have to be weighed against plans to retire the station in 2030. That schedule assumes that one or more commercial space stations will be in operation by the late 2020s to enable an orderly transition from the ISS to those facilities.

Montalbano, in his remarks, hinted at the ability to extend the ISS beyond 2030 if necessary. “We’ll be ready to go longer if that’s what the different agencies want us to do, but right now we’re planning to 2030,” he said, with such discussions likely later in the decade. “Do we go to 2030 or does it make sense to go longer? If so, we’ll work that together with all the different space agencies and their respective governments.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...