Generating Power from Space

At the beginning of this year, the SSPP or Space Solar Power Project of the California Institute of Technology launched a prototype SSPD or Space Solar Power Demonstrator into orbit. They have an aspiring plan of gathering solar power in space. Not only will the SSPD prototype test several vital components, but also beam the energy it collects back to earth.

Outer space has a practically unlimited supply of solar energy. This energy is constantly available, never subject to cloud cover, and is unaffected by seasons and cycles of day and night. Therefore, space solar power is a tremendous step towards harnessing limitless amounts of clean and free energy.

The launch is a major milestone for the project. In full realization, the SSPD will have several spacecraft in the form of a constellation for collecting sunlight. It will then transform the sunlight into electricity, and transmit it wirelessly over to earth. The project will provide electricity wherever necessary, including places that do not have access to reliable power.

A SpaceX rocket launched the 50-kg SSPD into space on a Transporter-6 mission. The demonstrator has three main experiments. Each handling a vital technology of the project.

The first experiment is the DOLCE. This is the on-orbit, deployable, ultralight composite. Measuring 6 x 6 feet, this structure is meant to demonstrate the packaging scheme, architecture, and deployment mechanism of the future modular spacecraft that the scientists eventually plan to make up as the kilometer-long constellation of the power station.

The next experiment is the ALBA. This is a collection of various types of photovoltaic cells. Numbering 32 in total, this experiment allows the scientists to make an assessment of the effective performance of each type of photovoltaic cell in the extremely hostile environment of space.

The final experiment is the MAPLE. This is a microwave array for transferring power at low orbit. It consists of an array of lightweight flexible power transmitters at microwave ranges. With precise timing control systems, it can focus the power onto two different receivers selectively. This experiment will demonstrate the transmission of wireless power at a distance in space.

The SSPD has an additional fourth experiment. This is a box of electronics interfacing the prototype with the Vigoride computer while providing a control for the three experiments.

The ALBA or photovoltaic cell experiment will require up to six months of testing before it can generate new insights into the most suitable photovoltaic technology for space power applications. MAPLE constitutes a series of experiments, starting from verification of the initial functionality to an evaluation of the system performance under extreme environments over time.

DOLCE has two cameras on booms that can deploy as necessary, and more cameras on the electronics system. They will monitor the progress of the experiments and provide a feedback stream to earth. According to the SSPD team, they expect to have a complete assessment of the experiments’ performance within a few months.

In the meantime, the team still has to deal with numerous challenges. This is because it is not possible to guarantee anything about conducting an experiment in space.