MUNICH, Germany — The international space station (ISS) partners have begun reviewing their on-board hardware with the goal of certifying it for use until 2028 even as they seek ways to reduce the annual operating costs of the orbital complex, the partners said in a joint statement March 11.

Meeting in Tokyo, the heads of space agencies from the United States, Russia, Europe, Japan and Canada expressed approval of U.S. President Barack Obama’s proposal to continue NASA’s use of the station until 2020, and said operating beyond that date should also be considered.

“[T]here are no identified technical constraints to continuing ISS operations beyond the current planning horizon of 2015 to at least 2020 … the Partnership is currently working to certify on-orbit elements through 2028,” the five agencies said in a statement, adding that they share a “strong mutual interest in continuing operations and utilization for as long as the benefits of ISS exploitation are demonstrated.”

The 2028 date was selected because it will mark the 30th anniversary of the first ISS module, which Russia placed into orbit in 1998.

The partners also agreed to seek ways to reduce the annual cost of ISS operations. Simonetta Di Pippo, space station director at the 18-nation European Space Agency (ESA), said in a March 11 interview that several ideas were floated. Di Pippo said these include new-generation water-regeneration systems to reduce the need to launch fresh supplies, and an increase in the upload capability of cargo carriers, including Europe’s Automated Transfer Vehicle, which is scheduled to make its second flight to ISS later this year.

Di Pippo said the all-but-certain decision to extend the station’s operations to 2020, if not longer, buttresses the argument in Europe to modify the Automated Transfer Vehicle to permit it to return to Earth with station supplies. ESA has made preliminary studies of what is called the Advanced Re-entry Vehicle, but has not begun hardware development, in part because of uncertainties over how long ISS would remain in service.

As currently designed, the Automated Transfer Vehicle, after bringing supplies to the space station, is loaded up with refuse and guided back into the atmosphere to burn up upon re-entry.

Peter B. de Selding was the Paris bureau chief for SpaceNews.