[image-51][image-78][image-94][image-110]Cheryl L. Mansfield
NASA's John F. Kennedy Space Center
Even though the structural elements of the International Space Station prepared in the processing facility at NASA's Kennedy Space Center in Florida are now in space, the team at Kennedy continues to support the orbiting laboratory in a number of ways.
As evidence of that support coupled with international cooperation, hardware destined for the space station just left Kennedy, headed for the Tanegashima Space Center in Japan. There it will be turned over to the Japan Aerospace Exploration Agency (JAXA) in preparation for launch on the H-II Transfer Vehicle 4 (HTV-4) mission this summer.
"The HTV-4 elements are trucked from Kennedy to Chicago, then moved by air freight to Narita, Japan, where a complicated combination of ground and ocean ferry transfers will be used to deliver them to Tanegashima," explained Steve Bigos, Space Station Orbital Replacement Unit project manager at Kennedy. "We provide an on-site coordinator at the JAXA launch site in order to help ensure the three elements arrived safely and to provide coordination between JAXA and NASA during installation into the JAXA launch vehicle."
The Kennedy team also completed the planning, processing and integration of unpressurized Orbital Replacement Units (ORU) for the Main Bus Switching Unit (MBSU) and Utility Transfer Assembly (UTA) -- both important elements for keeping the space station running.
"The Utility Transfer Assembly is a critical component of the S3 and P3 truss segments' Solar Alpha Rotary Joints. Its function is to pass electrical power generated by the solar arrays to the other ISS elements and payloads," said Bigos.
"The Main Bus Switching Unit also is part of the system transferring electrical power from the arrays. This ORU provides switching capability for the various power channels and sources.
"At Kennedy, we performed periodic maintenance tasks and installation of the MBSU and UTA ORUs onto their respective Flight Releasable Adapter Mechanism (FRAM) hardware and Flight Support Equipment (FSE)," said Bigos. "This hardware adapts the ORUs and payloads to fit both the launch vehicle and on-orbit locations."
Also included in the shipment was the Space Test Program-Houston 4 (STP H-4) payload whose team performed development testing of their payload using Kennedy's Payload Rack Checkout Unit (PRCU) and EXPRESS Logistics Carrier (ELC) simulator. The STP H-4 contains seven experiments for investigating space communications, Earth monitoring and materials science.
"For the STP H-4 payload, we supported the payload developer by providing working space and crane operators, and we also performed adapter plate installation," explained Bigos.
While the size of the payloads has changed since the space station's completion, the current work builds on the experience from those days.
"During the ISS construction phase, we performed assembly of very large ISS structures, such as the nodes, trusses and EXPRESS carriers launching on the space shuttle. Those structures often contained ORUs; in fact, MBSUs and UTAs have both been previously launched on ISS trusses in the past," said Bigos. "Now that construction of the ISS is complete, we prepare smaller ORUs to keep the ISS operating. The ORUs are mostly plug-and-play components that have periodic replacement schedules, and they are launched on expendable vehicles. So we are performing similar assembly and checkout tasks, but on a smaller scale."
The shipment to Japan for the HTV-4 launch continues the international cooperation that began during construction of the station, as the partner nations work together to bridge any gaps in the process.
"The language barrier can be the most challenging aspect of dealing with the Japanese, although we were fortunate to have JAXA counterparts with extensive skill in English," said Bigos.
"Also, the Japanese are inclined to work-detailed processes at a higher management level than we are accustomed to," he added, "so as a project manager, I found myself immersed in engineering detail that for an American project I would not typically need to know."