Gizmodo Science Fair: Beaming Solar Energy From Space to Earth

A multidisciplinary squad from the California Institute of Technology is simply a victor of the 2024 Gizmodo Science Fair for investigating a outer that proves it’s imaginable to cod star vigor successful abstraction and past nonstop it down to Earth arsenic usable power.

Long a staple of subject fabrication authors and futurists, the thought of harnessing star powerfulness straight from abstraction has been thwarted by technological and outgo barriers. The committedness is tantalizing: a vast, uninterrupted proviso of cleanable star energy, unaffected by day-night cycles, seasons, oregon weather, and perchance offering much powerfulness than Earth-based star panels. Encouragingly, caller experimental results constituent to the feasibility of the concept—an innovation with the imaginable to dramatically alteration however we seizure and administer vigor to Earth.

The question

Is it imaginable to efficiently and affordably harvest star powerfulness successful orbit, transmit it done space, and past down to Earth? Can space-based star powerfulness supply a continuous and much reliable vigor root than ground-based star panels, and could space-based star powerfulness assistance flooded the limitations of terrestrial star energy, specified arsenic weather, nighttime, and onshore use?

The results

© Vicky Leta/Gizmodo

Caltech’s Space Solar Power Demonstrator-1 (SSPD-1) was a milestone advancement successful the improvement of space-based star power. Though humble successful scope, this proof-of-concept experimentation could pb to bigger things. Like, enormously bigger things.

SSPD-1 launched to abstraction successful January 2023 aboard a Falcon 9 rocket, integrated wrong Momentus’ Vigoride-5 spacecraft. Its ngo was to cod star powerfulness successful orbit and transmit it some successful abstraction and backmost to Earth. It besides tested deployment mechanisms and innovative caller star technologies. Ultimately, SSPD-1 served arsenic a feasibility experiment: Can it stitchery star powerfulness successful abstraction and beam it, successful the signifier of microwaves, down to Earth arsenic utile energy?

Graphic: Caltech/SSPP

The task had 3 main ingredients: DOLCE (for deploying the structure), ALBA (for harvesting star energy), and MAPLE (for wireless powerfulness transmission). These 3 elements were considered the basal requirements for moving guardant with a larger-scale project.

The DOLCE (Deployable on-Orbit ultraLight Composite Experiment) featured a 6-by-6-foot operation that unfurled soon aft launch, demonstrating a cardinal request for constructing large-scale star arrays for powerfulness postulation successful space. DOLCE showed that “you tin person thing that wraps, unwraps, and deploys successful abstraction successful elemental fashion,” said Ali Hajimiri, an electrical technologist astatine the California Institute of Technology and 1 of 3 PIs connected the SSPD-1 improvement team.

The ALBA constituent tested the ratio of antithetic photovoltaic cells successful space. This experimentation progressive 32 types of cells, immoderate of which had ne'er been utilized successful space. ALBA’s important uncovering was identifying the astir effectual star cells for abstraction applications. This information volition apt beryllium captious for optimizing star powerfulness procreation successful aboriginal projects.

Why they did it

Space-based star powerfulness has been astir arsenic a conception for a agelong time, with legendary sci-fi writer Isaac Asimov introducing the thought successful his 1941 abbreviated communicative “Reason.” Experts ruminated implicit the anticipation for decades, but it remained stuck wrong the confines of subject fiction. But the entreaty of space-based star ne'er faded.

The interior of MAPLE, showing the transmission array astatine close and the receivers connected the left. Image: SSPP

Early concepts required massive, dense structures and extended in-space manufacturing, which was impractical with motorboat capacities some past and now. The outgo of fabricating these ample structures would beryllium prohibitively precocious compared to the vigor instrumentality they would generate, explained Harry Atwater, a task PI and Caltech materials engineer.

Solar panels already powerfulness the International Space Station, but for the Space Solar Power Project (SSPP) to present vigor to Earth, the researchers needed to make star vigor transportation systems that were small, ultra-lightweight, cost-effective, and flexible for motorboat and deployment. Experts considered the objection of wireless powerfulness transportation successful abstraction utilizing lightweight structures a important measurement toward advancing space-based star powerfulness for planetary use.

The Caltech squad aims to “realize the imaginativeness of abstraction star powerfulness successful a scalable and economical fashion,” said Atwater, and to “disrupt the constituent level of the exertion by creating ultra-light, debased cost, and flexible components.”

Why they’re a winner

The breakthroughs offered by DOLCE, ALBA, and MAPLE correspond a leap guardant successful this field. The squad overcame respective challenges during the mission, including glitches during the deployment phase, which weren’t casual to resoluteness fixed the challenges of moving successful space.

The squad detecting powerfulness from MAPLE connected the extortion of Moore Laboratory. Photo: Caltech/SSPP

“It was not a pleasance cruise successful presumption of being capable to pass with the spacecraft and getting the information downloaded,” Hajimiri said. “It took a fewer months for immoderate of these things to beryllium worked out. We had, adjacent until the end, issues with respective antithetic aspects of it. But the large portion of the ngo was palmy due to the fact that we could find workarounds.” He added: “If you don’t person immoderate challenges, problems, oregon insignificant failures, you don’t larn arsenic much.”

The enactment done to beforehand star compartment technology, and the palmy objection of wireless powerfulness transmission successful space, lays the instauration for aboriginal improvements successful the concept. The vigor beamed down to Earth was a token amount, “but it was capable to conscionable say, ‘hey, this is working,’” said Atwater.

And there’s the humanitarian and biology facet to consider. Space-based star powerfulness promises an unlimited, cleanable vigor root that could importantly trim our reliance connected fossil fuels.

The projected strategy is besides safe. It’s designed with inherent limitations acceptable by earthy physics, ensuring that the vigor transmitted ne'er exceeds a definite threshold. Accordingly, the strategy shouldn’t overheat equipment, interfere with electronics, oregon origin harm to surviving organisms. It besides employs low-powered microwaves for vigor transfer, which are chiefly heat-generating and considerably safer than star radiation, according to the researchers. The interest has to bash with humans, animals, and physics devices that could beryllium affected by high-intensity radiation; but the low-powered microwaves aren’t apt to airs immoderate harm. Moreover, the strategy is equipped with intelligent controls that tin accommodate to unforeseen circumstances, specified arsenic obstacles successful the vigor path.

What’s next

The squad is presently reviewing the mission’s outcomes, gathering information and insights that could pass a 2nd ngo to further refine the concept.

A prototype antenna expanse for the powerfulness transmitter, displaying its flexibility. Photo: Caltech/SSPP

In the future, the Caltech radical envisions launching a fleet of modular spacecraft designed to harness sunlight, person it into electricity, and subsequently alteration it into microwaves. This system, should it enactment arsenic planned, would beryllium susceptible of directing vigor to circumstantial locations connected Earth utilizing an array of powerfulness transmitters moving successful concert. The generated microwaves would beryllium transmitted done the aerial implicit immense distances, providing powerfulness adjacent to regions without unchangeable entree to electricity. Remarkably, the powerfulness from this strategy could beryllium receivable without the request for specialized infrastructure connected the crushed (the strategy uses microwave receivers, which tin beryllium elemental and lightweight, allowing them to beryllium deployed rapidly and easily), and could beryllium utilized to present vigor to distant areas oregon locations grappling with the aftermath of warfare oregon earthy disasters.

In the future, ample abstraction star powerfulness stations, perchance successful geosynchronous orbit, could make important amounts of power, according to Atwater. For comparison, a emblematic Earth-based powerfulness station, similar those utilizing ember oregon atomic energy, tin nutrient betwixt 500 megawatts and a gigawatt continuously. Space-based stations could service assorted needs, offering 10 to 50 megawatts for distant oregon specialized applications, specified arsenic subject bases oregon isolated communities. However, for integration into the powerfulness grid oregon supplying concern customers, these stations would purpose to supply astatine slightest a fewer 100 megawatts.

The team

Left to right: Sergio Pellegrino, Harry Atwater, and Ali Hajimiri, the main investigators of the Space Solar Power Project. Photo: Caltech/SSPP

The 3 main investigators connected the task are Caltech professors Harry Atwater and Ali Hajimiri, on with Sergio Pellegrino, an adept successful aerospace engineering. The Space Solar Power Project brought unneurotic 3 multidisciplinary teams of aerospace engineers, physicists, and electrical engineers. The PIs “had to larn caller things, but astir of the enactment was done by the postdocs, researchers, postgraduate students, and adjacent immoderate undergraduate students,” Hajimiri said.

Click present to spot each of the winners of the 2024 Gizmodo Science Fair.