A NASA official said Jan. 30 that NASA has effectively reached full utilization of the International Space Station due to limitations on crew time and the ability to ferry cargo to and from the station.
The agency has reached its quota of the station’s resources to conduct research, said Kurt Costello, NASA’s chief scientist for the International Space Station, speaking at a meeting of the National Academies Committee working on the Decadal Survey of Biological and Physical Sciences in Space.
“As we get into this discussion about full utilization,” he said, “I’ll tell you that I think we’re in.” “We have enhanced the station’s capabilities not only to conduct research but to conserve the usage resources we have.”
For much of the station’s history, the limitations of conducting research on the station were available to the crew’s time. However, he said that became less of a problem after the introduction of commercial crew vehicles that allow NASA to support four astronauts on the American portion of the station, rather than three, providing more crew time.
Transporting goods to and from the station has become a bigger problem. Costello said that is reflected in the restrictions on transporting large cargo in so-called “big bags” that are larger than a standard cargo carry bag, as well as “conditional stowage” of items such as biological samples that require keeping in a freezer or cooler.
The freight vehicles currently supporting the station cannot accommodate more research payloads, particularly those requiring bulky big bags or air-conditioned storage. “We fly everything full,” he said, the only question being whether the car first reaches its maximum payload size or mass. “Either by mass or by volume, we fill those compounds completely.”
The station itself is cluttered, Costello shows photos in his presentation of “enhanced storage” at the station, with cargo bags lining the aisles at the station because there is nowhere else in the station’s units to put them. This also affects the use.
“To get equipment to search, for some of our investigations, the crew has to go through that storage and find the right bags,” he said. “We are currently seeing enhanced amounts of crew time being added to crew activities just for stowage recovery.”
Costello said NASA is counting on the introduction of new vehicles to help, including the first flights of Sierra Space’s Dream Chaser cargo vehicle and Japan’s HTV-X, an upgraded version of the HTV cargo vehicle, as well as Boeing’s CST-100 Starliner commercial crew vehicle. “We are waiting for three new vehicles to be able to provide us with the same crew and cargo service capabilities that we have seen over the past three and a half years.”
If NASA wants to increase its use, he said, the agency and its researchers will need to rethink their approaches. This involves doing more analysis on the station itself, rather than sending samples back to Earth for study. This is particularly important, he said, since the capacity to send cargo to Earth is much lower than the capacity to deliver cargo to the station.
He also said researchers need to reduce the “back and forth redundancies” where research equipment is sent to the station, then brought back and modified for a future mission to the station. “In other words, you don’t fly a big big item and then have to bring it back for your next experiment,” he said. “If we can reduce accommodations with big bags that need to fly up and down and back again, we can help everyone.”
He pointed out that the study only dealt with the resources related to NASA’s share of the resources of the International Space Station. Half of the US portion is allocated to the ISS National Laboratory, which is operated by CASIS. Costello said there is an ongoing study looking at the use of national laboratory resources.