Caltech Successfully Concludes SSPD-1Mission

Ibadan, 19 January 2024. – Caltech’s Space Solar Power Demonstrator (SSPD-1) has reached its end, having successfully demonstrated the ability to beam power wirelessly in space. The mission measured the efficiency, durability, and function of various types of solar cells in space; and gave a real-world trial of the design of a lightweight deployable structure to deliver and hold the aforementioned solar cells and power transmitters.

The project comprised three main experiments, each testing a different technology; DOLCE (Deployable on-orbit ultraLight Composite Experiment); ALBA, and MAPLE (Microwave Array for Power-transfer Low-orbit Experiment). DOLCE demonstrated the novel architecture, packaging scheme, and deployment mechanisms of the scalable modular spacecraft that would eventually make up a kilometer-scale constellation to serve as a power station.

Likewise, ALBA measured the photovoltaic performance of three entirely new classes of ultralight research-grade solar cells, none of which had undergone in-orbit testing before, over the course of more than 240 days. Over ALBA’s lifespan, the team collected enough data to observe changes in the operation of individual cells in response to space weather events like solar flares and geomagnetic activity.

Similarly, MAPLE demonstrated its ability to transmit power wirelessly in space and to direct a beam to Earth. MAPLE experiments lasted for eight months after the initial demonstrations, with the team pushing MAPLE to its limits to expose and understand its potential weaknesses to apply lessons they learned to future design.

SSPD-1 represents a major milestone in a project that has been underway for more than a decade. It launched on January 3, 2023, aboard a Momentus Vigoride spacecraft as part of the Caltech Space Solar Power Project (SSPP), with Professors Harry Atwater, Ali Hajimiri, and Sergio Pellegrino leading the project.