Four (4) hours. Do you know what does it mean to plan a four hour activity on the Space Station? The latest activity with a similar duration was in 2007 and it was the first CNSM measurement on an astronaut. At that time two astronauts were involved and the activity, planned for one hour and half, went well beyond two and a half hours. Just to try to explain what does it mean planning a four hour activity. In a space activity, unexpected issue on a 15 minute activity could cause 3 months of data loss.
Ok, let’s start from the beginning. Who is following ALTEA activities on Twitter (official ALTEA account @ISS_ALTEA) or on Facebook (ALTEA official page) already knows that after being for 6 years inside the UsLab, it was planned to move ALTEA to Columbus in a new configuration.
ALTEA has been in this position in the UsLab since the 22nd of July 2011 (link in Italian), when the Japanese astronaut Satoshi Furukawa moved it from the previous location. At that time the activity was relatively easy, because the particle detectors were already configured on the support structure. All the astronaut had to do was simply to move the whole thing into the new location inside the American module and to start a new measurements.
Before this activity, it was Paolo Nespoli (link in Italian) who did a great job in assembling the entire detector configuration starting from a dismounted ALTEA in a bag. You can find here the images of that activity. That activity took Paolo more than four hours to complete (can’t remember how long it was planned for), and the activity was only about assembling ALTEA.
This move to Columbus, on the contrary, implied for André to disassemble ALTEA and the support structure completely, put everything in a bag, and then reassemble everything in a new configuration inside Columbus. Let’s consider that the ALTEA Shield support structure is composed by modular plates that need to be assembled just like a jigsaw-puzzle:
This is the configuration assembled by Paolo Nespoli
André Kuipers had to build the configuration named Shield Shield. Four plates have to be assembled in a planar configuration to hold only three SDUs (the particle detectors of ALTEA). Two SDUs are shielded by shielding tiles of different thickness placed above and beyond the particle detector. The third SDU, without shielding, acts as reference. This permits to assess the effectiveness of the shielding by comparing the type and the number of revealed particles.
So it was not an easy task for André, taking into account that he had to move to a different module, on a different pc, with an updated software. The MARS center in Naples who was supporting the operations on our behalf from ground, planned an 8 hour shift to manage possible delay of the activity.
But despite our fears, André completed his activity without any hesitation, without any error, without any issue, and in less than three and a half hours, ALTEA was in Columbus in its new configuration, sending valuable science data to ground.
Here are the pictures of the new configuration:
And after the detectors were inserted in the Columbus racks
Our best congratulations to André for the really good job. And good new measurements to ALTEA.
PS: The PromISSe mission ESA blog talked about ALTEA activity by André.