A few days ago, SpaceX’s Falcon 9 rocket successfully launched 114 satellites into the low Earth orbit, including the Space Solar Power Demonstrator (SSPD) developed by California Institute of Technology (Caltech). In the coming weeks, the 110lb (50kg) prototype will try to identify materials, designs and techniques that can help create the most efficient and cost-effective solar energy solution.
The Falcon 9’s Transporter-6 mission allows several companies to “share a ride” by sending their satellites to space, including the SSPD prototype, which comprises three experimental instruments, namely DOLCE, ALBA, and MAPLE.
- DOLCE (Deployable on-Orbit ultraLight Composite Experiment): The technology allows the deployment of an ultra-lightweight 1.8-m square structure demonstrating the architecture, packaging, and deployment mechanism of a modularized spacecraft; the composite can be folded and unfolded with ease and combined into a 1-km-scale power station.
- ALBA: ALBA comprises 32 different solar cells, allowing the prototype to determine which cell(s) can survive in extreme space environments.
- MAPLE (Microwave Array for Power-transfer Low-orbit Experiment): The instrument comprises a pair of flexible microwave transmitters enabling the concentration of power on two separate receivers selectively, demonstrating mid- and long-range power transmission in space.
The said three instruments will help realize the establishment of a solar power station in space. However, Michael Kelzenberg, senior researcher at Caltech, emphasized that the first SSPD experiment does not aim to generate solar power for Earth; instead, the purpose for this trip is to identify which materials, designs and techniques are suitable for generating solar power in space so that an efficient and affordable solution can be developed.
Scientists have high expectations for space-based solar power. In 2007, the US National Space Society predicted that a half-mile band of photovoltaic cells orbiting Earth could generate as much energy as all of the remaining oil on the planet within just 1 year.
Previous studies have indicated that high-intensity lasers can transmit 80% of solar energy in space to the receiver network on Earth and provide clean energy worldwide, which is still impossible for the existing grids. In addition to the requirement of technical improvements, the biggest challenge of spaced-based solar power is the high cost of aerospace engineering. Nevertheless, as Ali Hajimiri, professor at Caltech and co-director of the Space Solar Power Project, emphasized, the SSPD prototype still signifies a crucial step forward.