  A new opportunity for astronomy, cosmology, physics, and atmospheric
observations is the possibility to fly stratospheric payloads at 30 - 40 km of
altitude during the polar night. The absence of solar irradiation for long
periods, and the extremely low temperature and stable environment of the winter
stratosphere represent ideal environmental conditions while performing
astrophysical observations. Here we present a small and efficient platform,
able to communicate, supply power and navigate in the harsh environment of the
polar stratosphere. After a balloon failure in January 2017, the payload was
successfully flown in December 2017 from 78$^\circ$N, in Longyearbyen,
Svalbard, Norway. Duration was limited to 21 hr, due to a southern trajectory
that caused solar illumination and loss of lift. The instrument acquired and
transmitted environmental data, and the thermal performance of the power system
are outstanding. The payload also included a set of attitude sensors, to
monitor payload movements. The information collected on this flight is
essential to qualify the attitude control system sensors, and for the design if
the thermal and power system of the next generation LSPE-SWIPE telescope,
devoted to the measurement of the polarization of the Cosmic Microwave
Background radiation from a stratospheric balloon during the Arctic polar
night.
