ASTERIA (Arcsecond Space Telescope Enabling Research in Astrophysics) is a technology demonstration and opportunistic science mission to conduct astrophysical measurements using a CubeSat. Originally envisioned as a project for training early career scientists and engineers, ASTERIA's technical goal is to achieve arcsecond-level line-of-sight pointing error and highly stable focal plane temperature control. These technologies are important for precision photometry, i.e., the measurement of stellar brightness over time. Precision photometry, in turn, provides a way to study stellar activity, transiting exoplanets, and other astrophysical phenomena.
ASTERIA is a 6U CubeSat (roughly 10 x 20 x 30 cm, 10 kg) that is currently operating in low-Earth orbit. The payload consists of a lens and baffle assembly, a CMOS imager, and a two-axis piezoelectric positioning stage on which the focal plane is mounted. A set of commercial reaction wheels provides coarse attitude control. Fine pointing control is achieved by tracking a set of guide stars on the CMOS sensor and moving the piezoelectric stage to compensate for residual pointing errors. Precision thermal control is achieved by isolating the payload from the spacecraft bus, passively cooling the detector, and using trim heaters to perform small temperature corrections over the course of an observation.
ASTERIA is currently in an extended mission to search for new exoplanet transits around nearby, bright stars. The extended mission also provides long-term validation of hardware and software for use on future projects.
August 14, 2017 - Launched to International Space Station (ISS)
November 20, 2017 - Deployed from the ISS to begin mission
- lens and baffle assembly
- CMOS imager
- two-axis piezoelectric positioning stage on which the focal plane is mounted