The Micro-X sounding rocket is a NASA funded X-ray telescope payload that
completed its first flight on July 22, 2018. This event marked the first
operation of Transition Edge Sensors (TESs) and their SQUID-based multiplexing
readout system in space. Unfortunately, due to an ACS pointing failure, the
rocket was spinning during its five minute observation period and no scientific
data was collected. However, data collected from the internal calibration
source marked a partial success for the payload and offers a unique opportunity
to study the response of TESs and SQUIDs in space. Of particular interest is
the magnetic field response of the NIST MUX06a SQUID readout system to tumbling
through Earth's magnetic field. We present a model to explain the baseline
response of the SQUIDs, which lead to a subset of pixels failing to "lock" for
the full observational period. Future flights of the Micro-X rocket will
include the NIST MUX18b SQUID system with dramatically reduced magnetic
susceptibility.Comment: 6 pages, 6 figures, LTD19 conference proceeding