  Space solar power (SSP), envisioned for decades as a solution for continuous,
stable, and dynamically dispatchable clean energy, has seen tremendous interest
and a number of experimental demonstrations in the last few years. A practical
implementation has been elusive to date, owing to the high launch costs
associated with heavy, rigid photovoltaic (PV) and wireless power transfer
(WPT) arrays. Lightweight and flexible solutions for WPT have been demonstrated
terrestrially but, to date, have not been deployed and tested in space. In this
paper, we present an experimental space demonstration of a lightweight,
flexible WPT array powered by custom radio frequency integrated circuits
(RFICs). The transmit arrays, receive arrays, and the rest of the system were
operated and tested for eight months in Low Earth Orbit (LEO). Results from
these experiments, including pointing of the array's beam to Earth and its
detection by a ground station, are presented and discussed in detail.
Observations and results from this mission uncover existing strengths and
weaknesses that inform future steps toward realizing SSP.
