Hot surprise on the space transporter CYGNUS

The 25 scientists of the project "SAFFIRE V" look back on the flight of Cygnus NG-14 with mixed feelings. The reason: One of the two experiments on board the space transporter could not be started as planned. The other, functioning experiment, however, caused a surprise. Also involved were two scientists from the Center for Applied Space Technology and Microgravity (ZARM) at the University of Bremen.

The start of the experiments on Cygnus NG-14 was awaited with great excitement, because the scientists hoped to gain new insights into fire safety on board of spacecrafts. This was the fifth time that the CYGNUS capsule was used for these kind of experiments, whose actual purpose is to deliver supplies and new experiment setups to the International Space Station ISS and then burn up in the Earth's atmosphere on its way back. After the CYGNUS undocked from the ISS on Jan. 6, 2021, the SAFFIRE V experiments were ready for ignition at 3:30 a.m. (CET) on Jan. 7. In SAFFIRE V an acrylic board will be ignited in such a way that the flame is spread "upstream" or “downstream” across the material by an air flow with Normoxic atmosphere (700 millibars, 26.5% oxygen as in future exploration missions). Unfortunately, the first of the two experiments ("downstream") could not be ignited due to a technical problem. In the second experiment, on the other hand, in which the flame was supposed to spread against the flow, something unexpected happened: the three thermocouples attached to the opposite end of the ignition point were not supposed to show any significant temperature increase during the 6-minute burning period. However, the measurements of one of the thermocouples suddenly increased after only three minutes and reached a peak value of 185° C.

The scientists involved will now have to puzzle for about a week until they can obtain the images from the experiments and figure out what was responsible for this unexpected temperature rise. An initial evaluation based on the measurement data of the flame radiation values, the exhaust gas temperatures, the O2, CO, CO2 concentrations as well as the air humidity values has already begun.

The SAFFIRE V project is financed by NASA.

For further information:

Christian Eigenbrod
christian.eigenbrod[at]zarm.uni-bremen.de
+49 421 218-57780

For general media inquiries:

Birgit Kinkeldey
birgit.kinkeldey[at]zarm.uni-bremen.de
+49 421 218-57750