When the Japanese HTV-9 Kounotori cargo ship lifted off May 20 to deliver supplies and science equipment to the International Space Station, a landmark chapter in the station’s story drew to a close – and a new chapter, helping to chart the course for Artemis-Generation voyages into the solar system, began.
Among the cargo the spacecraft delivered to the space station May 25 is the final NASA “EXpedite the PRocessing of Experiments to the Space Station” multipurpose payload shelving unit. Better known as EXPRESS Racks, these permanent fixtures on the station support a variety of research experiments – providing power, protective storage, cooling and heating, command and data communications and easy transport for up to 10 small payloads each.
“Since our earliest ventures into space, we’ve sought more efficient, longer-term ways to conduct cutting-edge science in low-Earth orbit and beyond,” said Bobby Watkins, manager of the Human Exploration Development & Operations Office at Marshall Space Flight Center. “The EXPRESS Racks have been a cornerstone of science on the space station, and a vital part of our mission to make space exploration safer and more comfortable for our crews, and also reap untold scientific benefits back home on Earth.”
Marshall oversees space station hardware development and implementation for NASA, and NASA personnel in Marshall’s Payload Operations Integration Center monitor experiments continuously, every day of the year. At any given time, up to 80 experiments can be in process, controlled by station crew members or from the ground. The racks operate at near capacity around the clock, and data compiled by Shaun Glasgow, project manager for the EXPRESS Racks at Marshall, and his team reveals a staggering fact: Since installation and startup of the first space station rack in 2001, NASA has logged more than 85 total years of combined rack operational hours using these facilities.
“The sheer volume of science that’s been conducted using the racks up until now is just overwhelming,” Glasgow said. “And as we prepare to return human explorers to the Moon and journey on to Mars, it’s even more exciting to consider all the scientific investigations still to come.”
Once the new rack is installed, 11 total racks will be on the station – the eight original EXPRESS Racks and three Basic EXPRESS Racks, more streamlined and versatile modern versions. Each is about the size of a refrigerator and comes equipped with up to eight configurable lockers and two drawers to house payloads. Experiments can be conducted, removed independently and returned to Earth depending on varying time requirements.
The first EXPRESS rack was successfully tested aboard the space shuttle in 1997. The first two completed racks were delivered to the space station on STS-100 in 2001 and have been in continuous operation since – as have all the subsequent added racks.
The new rack is expected to be installed and operational by fall.
The technology is a legacy of the space shuttle program, which conducted a raft of scientific investigations from its versatile “mid-deck lockers” – slotted payload storage racks – during more than 130 flights between 1981 and 2011. “Those compact, standardized units became the model for developing the larger, more efficient racks we employ today,” Glasgow said.
He speculates on how the EXPRESS Racks will carry on that engineering legacy, impacting future hardware development as humanity extends its reach ever farther into the solar system. “Science leads, but engineering innovation is the true hallmark of NASA’s accomplishments for more than a half-century,” he said. “The work we did over those years got us here. Now it’s our turn to chart the future, delivering the equipment to carry science and discovery missions into the next century and beyond.”
A final example of that innovative spirit is ready to get to work.
Funded by NASA’s Johnson Space Center, the EXPRESS Racks were developed by engineers at the Boeing Co. and Marshall, which jointly built and tested the racks at Marshall in the late 1990s.
Editor’s note: Rick Smith, an ASRC Federal/Analytical Services employee, supports the Office of Strategic Analysis & Communications.