Loss of power for the ISS MFX-2 experiment
Time is a precious commodity – especially in a unique laboratory complex such as the International Space Station (ISS). When something fails to go to plan, the result is additional stress and strain for the planners, researchers and everyone downstream who is involved in experimentation – everyone is keenly waiting for his/her timeslot. Last week it was DLR's MFX-2 Planetary Simulator that was involved. This had to be rebooted following an unexpected loss of power and some data was lost. The loss of power possibly damaged the start-up file on the USB boot stick. It is possible that the USB boot drive suffered damage as a result of the additional radiation experienced at an altitude of 400 kilometres.##markend##
Troubleshooting took the entire week and was hampered by new configurations and additional test runs. The experiment was created in a strict design-to-cost climate. Consequently, it does not have much in the way of controllability from the ground. That would have meant significantly higher development and qualification costs. There simply was no funding available.
On Friday last week, we decided to use the spare boot stick, and (from approximately 09:00) MFX-2 operated for a few hours using the seventh of a total of 12 material test pieces. Provided that everything functions nominally, the dataset which is generated from a single orbit of the Earth will be adequate. However, that was something that we only came to realise last Tuesday, because last week the EML melting furnace was scheduled to operate for the first time. Since MFX-2 is accommodated in the same rack as the EML, it is not possible for the two experiments to be run in parallel. From today, however, we can analyse the remaining six test samples.
We need to have completed work on the MFX-2 measurement programmes by 10 August. Then, NASA will need those crucial vacuum and coolant connections for a different system. In other words – we are under pressure. However, we have most of the scientific data. Of course, the troubleshooting came at the expense of additional crew time. Happily, Alexander Gerst installed the new video monitoring unit for the Fluid Science Laboratory ahead of schedule in terms of the planned 5½ hours. He managed to cut half an hour off the planned time. Quite an achievement! Also, there was a great deal of commissioning work – the preparation of systems for experimental runs such as those in the BioLab, for example.