  This paper presents Rocket Experiment (REX) that was part of a dual payload
rocket campaign for NASA's sounding rocket Black Brant IX with water recovery
technology. This mission was a suborbital sounding rocket flight that was
launched and recovered on April 4, 2018 and targeted the Vela supernova
remnant. The purpose of REX was to classify the Technology Readiness Level of
onboard devices designed for space applications. The devices were two
wide-field X-ray telescopes consisting of a combination of Lobster-Eye (LE)
optics with an uncooled Timepix detector (256 x 256 px @ 55 um), and additional
sensors. The first telescope uses a two-dimensional combination of LE modules
with a focal length of 1 m and a Field of View (FOV) of 1.0 x 1.2 deg and
operates in the energy range of 3 - 60 keV. The second telescope was a
one-dimensional LE with a focal length of 250 mm and a FOV of 2.7 x 8.0 deg for
the energy range 3 - 40 keV. The X-ray telescopes were supplemented by a camera
in the visible spectrum with 1,280 x 1,024 px resolution, which was used to
obtain images of the observed sources and to verify the resulting pointing of
the rocket carrier. Other devices also include infrared array sensors and
inertial measurement units tested for future small satellite missions. The data
handler and communication system were built using the Robot Operating System,
and both the system and the electronics were deployed and operated in flight.
The hardware was successfully recovered after the launch and the data were
extracted.
