  The number of small satellites has grown dramatically in the past decade from
tens of satellites per year in the mid-2010s to a projection of tens of
thousands in orbit by the mid-2020s. This presents both problems and
opportunities for observational astronomy. Small satellites offer complementary
cost-effective capabilities to both ground-based astronomy and larger space
missions. Compared to ground-based astronomy, these advantages are not just in
the accessibility of wavelength ranges where the Earth's atmosphere is opaque,
but also in stable, high precision photometry, long-term monitoring and
improved areal coverage. Astronomy has a long history of new observational
parameter spaces leading to major discoveries. Here we discuss the potential
for small satellites to explore new parameter spaces in astrophysics, drawing
on examples from current and proposed missions, and spanning a wide range of
science goals from binary stars, exoplanets and solar system science to the
early Universe and fundamental physics.
