WASHINGTON — NASA has effectively achieved full utilization of the International Space Station given limitations on crew time and the ability to move cargo to and from the station, an agency official said Jan. 30. .
Speaking at a meeting of a committee of national academies working on the decadal survey for biological and physical sciences in space, Kirt Costello, NASA’s chief ISS scientist, said the he agency had reached the limits of its share of the station’s resources to do research.
“As we get into this discussion of what full utilization is, I will tell you that I believe we are already there,” he said. “We have maximized the station’s capabilities not only to do research, but also to maintain the utilization resources we have.”
For much of the station’s history, the limit to researching the station has been available crew time. However, he said that has become less of an issue after the introduction of commercial crew vehicles that allow NASA to support four astronauts on the US segment of the station, rather than three, providing more downtime. ‘crew.
Getting freight to and from the station became a bigger problem. Costello said this is reflected in the limitations of carrying large cargo in so-called “big bags” larger than the standard cargo transfer bag, as well as “conditioned storage” for materials such than biological samples that must be stored in a freezer or cooler.
The cargo vehicles currently supporting the station have no room for more research payload, especially those that require the large bulky bags or conditioned stowage. “We fly full,” he said, the only question being whether a vehicle reaches its maximum cargo volume or mass first. “Either by mass or volume, we completely fill these vehicles.”
The station itself is packed, with Costello showing pictures in his ‘enhanced storage’ presentation on the station, with cargo bags lining the station passageways as there is no other place in the pods station to place them. It also affects usage.
“To access research equipment, for some of our investigations, the crew has to go through this storage and find the right bags,” he said. “We are currently seeing an increase in crew time being added to crew activities just to retrieve stowage.”
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 its HTV cargo vehicle, as well as the CST. -100 commercial Boeing Starliner. crew vehicle. “We are expecting three new vehicles to be able to provide us with the same crew and cargo servicing capabilities that we have seen over the past three and a half years.”
If NASA wants to increase use, he said the agency and its researchers will have to rethink their approaches. This involves doing more analysis on the station itself, rather than sending samples to Earth for study. This is particularly important, he said, because there is far less capacity to send cargo to Earth than to transport cargo to the station.
He also said researchers should minimize “round trip iterations” where research equipment is sent to the station and then returned and modified for a future mission to the station. “In other words, don’t fly a really big object and then have to flip it over to do your next experiment,” he said. “If we can minimize those Big Bag accommodations that have to fly up and down and then fly back, we can help everyone.”
The study, he noted, only looked at resources for NASA’s share of ISS resources. Half of the American segment is allocated to the ISS National Laboratory, managed by CASIS. Costello said a study is underway on the use of national laboratory resources.