Exploring distant exoplanets once required astronomical budgets, but photonic chips are rewriting the rules. These cutting-edge integrated circuits, when paired with CubeSats, could make the study of alien atmospheres more accessible than ever before, opening up new possibilities for space exploration.
The Challenge of Costly Space Telescopes
The James Webb Space Telescope has redefined our ability to observe the universe, boasting a 6.5-meter mirror that captures more light than any previous space telescope. Yet, with a price tag of $10 billion, such technology is far from accessible to most astronomers. Seeking a more affordable alternative, researchers at Canada’s National Research Council have pioneered a revolutionary approach: integrating photonic chips into small, cost-effective CubeSats.
Photonic Chips: The Future of Astronomy
Photonic integrated circuits (PICs), which utilize light instead of electricity to process data, are already transforming industries by handling vast amounts of information in data centers. Now, astronomers are leveraging this technology to push the boundaries of what can be observed in space. Unlike traditional ground-based telescopes, which suffer from atmospheric interference, photonic chipsin space can capture detailed data from faint celestial objects without the blurring effects of Earth’s atmosphere.
How Photonic Chips Enhance Space Telescopes
The primary advantage of deploying photonic chips in space lies in their ability to miniaturize and reduce the cost of essential components. “The dream is a purely fiber and chip-based instrument with no other optics,” says Ross Cheriton, a leading photonics researcher at the National Research Council. By replacing traditional filters, lenses, and mirrors with compact chips, these devices offer superior stability, scalability, and affordability.
CubeSats and Photonic Chips: A Perfect Match
CubeSats, small and standardized satellites, have already proven their worth in space exploration due to their cost-effectiveness. The compact nature of photonic chips makes them an ideal fit for CubeSats, enabling these miniature satellites to conduct big science—like studying bright exoplanet systems that larger telescopes, such as the James Webb, can’t always focus on.
For less than $1 million, a CubeSat mission equipped with photonic chips could observe a star for extended periods, waiting for a planet to transit across its face. During this transit, the CubeSat would analyze the star’s spectrum, searching for slight changes indicative of gases in the planet’s atmosphere—potential signs of life.
A Breakthrough in Spectroscopy
As a proof of concept, Cheriton and his team, including undergraduate students, spent eight months designing and integrating a photonic chip into a custom CubeSat. Their silicon nitride photonic circuit sensor successfully detected CO2 absorption signatures in incoming light.
The design works by focusing light entering the CubeSat through a collimating lens into a fiber that directs it onto the photonic chip. The light then travels through a series of etched waveguides, including a ring resonator that amplifies specific wavelengths, which match a gas’s absorption spectrum. This selective filtering allows the CubeSat to detect the presence of specific gases with higher sensitivity than traditional spectrometers.
Looking Ahead: The Future of Astrophotonic CubeSats
While the astrophotonic CubeSat is still in its early stages, the potential is enormous. Although the current design hasn’t yet been tested in space, Cheriton’s team successfully demonstrated its capabilities in the lab, detecting CO2 using red light. They now plan to test the chip’s ability to detect oxygen—a critical milestone in the search for Earth-like planets.
The team presented their groundbreaking work at the Optica Advanced Photonics conference in July, marking a significant step forward in making space exploration more accessible and affordable. As this technology advances, the dream of discovering habitable exoplanets using photonic chips on CubeSats is becoming increasingly within reach.
