  The Colorado Ultraviolet Transit Experiment (CUTE) is a 6U NASA CubeSat
carrying on-board a low-resolution (R~2000--3000), near-ultraviolet (2500--3300
{\AA}) spectrograph. It has a rectangular primary Cassegrain telescope to
maximize the collecting area. CUTE, which is planned for launch in Spring 2020,
is designed to monitor transiting extra-solar planets orbiting bright, nearby
stars aiming at improving our understanding of planet atmospheric escape and
star-planet interaction processes. We present here the CUTE data simulator,
which we complemented with a basic data reduction pipeline. This pipeline will
be then updated once the final CUTE data reduction pipeline is developed. We
show here the application of the simulator to the HD209458 system and a first
estimate of the precision on the measurement of the transit depth as a function
of temperature and magnitude of the host star. We also present estimates of the
effect of spacecraft jitter on the final spectral resolution. The simulator has
been developed considering also scalability and adaptability to other missions
carrying on-board a long-slit spectrograph. The data simulator will be used to
inform the CUTE target selection, choose the spacecraft and instrument settings
for each observation, and construct synthetic CUTE wavelength-dependent transit
light curves on which to develop the CUTE data reduction pipeline.
