  We advocate a low-cost strategy for long-duration research into the
'milligravity' environment of asteroids, comets and small moons, where surface
gravity is a vector field typically less than 1/1000 the gravity of Earth.
Unlike the microgravity environment of space, there is a directionality that
gives rise, over time, to strangely familiar geologic textures and landforms.
In addition to advancing planetary science, and furthering technologies for
hazardous asteroid mitigation and in-situ resource utilization, simplified
access to long-duration milligravity offers significant potential for advancing
human spaceflight, biomedicine and manufacturing. We show that a commodity 3U
($10\times10\times34$ cm$^3$) cubesat containing a laboratory of loose
materials can be spun to 1 rpm = $2\pi/60$ s$^{-1}$ on its long axis, creating
a centrifugal force equivalent to the surface gravity of a kilometer-sized
asteroid. We describe the first flight demonstration, where small meteorite
fragments will pile up to create a patch of real regolith under realistic
asteroid conditions, paving the way for subsequent missions where landing and
mobility technology can be flight-proven in the operational environment, in
Low-Earth Orbit (LEO). The 3U design can be adapted for use onboard the
International Space Station (ISS) to allow for variable gravity experiments
under ambient temperature and pressure for a broader range of experiments.
