Image: AFRL

Air Force Spacecraft Will Beam Solar Power to Earth

Named Arachne, this new satellite will transfer solar energy wirelessly back to any location on the planet.

Military outposts often struggle to meet energy needs, particularly those in remote locations. In many cases, armed convoys have to pass through dangerous territories to deliver fuel, leaving the vehicles and their delivery teams vulnerable to attack. Alternatives offer some relief, but most technologies still suffer from severe limitations, mainly when the energy demand is high. Enter the Arachne spacecraft, a cutting-edge project scheduled for launch in 2024 designed to capture solar energy, convert it to radio frequency power, and then transmit that power to Earth. 

BACKGROUND: What is Arachne?

By 2019, the problem of supplying energy had led the U.S. Air Force Research Lab to consider more inventive solutions, including capturing solar energy above the atmosphere where it is more intense and delivering it wirelessly to any location on the planet. 

As stated by Major Tim Allen at the time, “[the project was] born out of an operational need to provide power to disadvantaged users,” like these forward operating bases, and that transmitting power from space offers “more safety to our troops so they don’t have to escort those convoys.” 

ANALYSIS: Using Arachne to Transmit Energy

In December 2020, the Air Force announced that primary contractor Northrup Grumman had delivered the first key component for their Arachne spacecraft. Named “Helios,” after the Greek sun god, this component will house and deliver the wireless conversion and transmission module that will transfer energy to the planet’s surface.

The module system still under development is called The Space Solar Power Radio Frequency Integrated Transmission Experiment, or SSPRITE.

Image: AFRL

Designed in partnership with CalTech who operates NASA’s Jet Propulsion Laboratory, Arachne represents the first real-world vehicle built under the AFRL’s Space Solar Power Incremental Demonstrations and Research (SSPIDR) project. 

Serving primarily as a testbed for the feasibility of three critical systems, the AFRL says that, “Arachne will demonstrate emerging technologies that support the ability to convert solar energy to radio frequency (RF) power, using innovative ‘sandwich tiles’ as well as the feasibility of transmitting that energy to the ground and converting it to usable power.”

Systems that operate above the atmosphere collect significantly more solar energy, and Northrop Grumman sees this benefit as a vital component of the system.

“If you have a spacecraft collecting solar energy [and] beaming it,” said systems engineer Rachel Delaney, “this spacecraft has nearly constant sunlight, and it is able to collect up to eight times more than a ground system would.”

OUTLOOK: The Future of Solar Power is Not on Earth

As of 2021, solar power for homes and cars is getting increasingly cheaper, challenging the idea that energy collected and beamed from space could never become an economically viable option for the commercial market. 

When the security and safety of military personnel serving worldwide are factored in, the cost of a project like Arachne, which can eliminate a significant danger already faced by such outposts, seems well worth it.

The team still faces many hurdles, and although key, the Helios component’s delivery is just the first step. After its scheduled launch in 2024, Arachne, Helios, and SSPRITE will finally provide the first real-world testing of such space-based solar energy systems’ viability.