Tiny SBC-Based Receiver May Help Unlock Secrets of Universe’s Cosmic Dawn

PRATUSH is envisioned as a radiometer in lunar orbit that could finally detect the whisper-like signal of hydrogen from the Cosmic Dawn.

The Cosmic Dawn marks one of the most transformative chapters in the history of the Universe. It was during this epoch, several hundred million years after the Big Bang, that the very first stars and galaxies began to form, bringing light to what had been a vast cosmic darkness. This era dramatically altered the Universe’s structure, paving the way for everything we observe today—from galaxies and clusters to planets and eventually life itself.

Yet, despite its significance, much about the Cosmic Dawn remains shrouded in mystery. Astronomers have long sought to capture the elusive signals from this period, but the faint radio imprints of hydrogen atoms, the so-called 21-cm line, have proven exceptionally difficult to detect on Earth due to overwhelming radio interference.

Introducing PRATUSH: A Pioneer in Cosmic Exploration

In an ambitious bid to probe this hidden era, scientists at the Raman Research Institute (RRI), an autonomous institute supported by the Department of Science and Technology (DST), Government of India, have proposed a pioneering mission called PRATUSH — short for Probing ReionizATion of the Universe using Signal from Hydrogen.

PRATUSH is envisioned as a radiometer in lunar orbit that could finally detect the whisper-like signal of hydrogen from the Cosmic Dawn. By positioning the instrument on the far side of the Moon—the quietest radio environment in the inner Solar System—the mission would shield itself from Earth’s cacophony of radio transmissions, opening a clear channel to the early Universe.

The Role of a Tiny but Powerful Computer

At the heart of PRATUSH’s innovative design lies an unexpectedly modest piece of technology: a compact single-board computer (SBC), roughly the size of a credit card. Built initially around a Raspberry Pi, the SBC is serving as the master controller for the radiometer system.

Far from being just a low-cost computing device, the SBC coordinates PRATUSH’s entire operation:

• Managing the antenna that collects cosmic signals.

• Overseeing the analog receiver that amplifies them.

• Controlling the Field Programmable Gate Array (FPGA) that converts these signals into digital fingerprints, mapping the brightness of the sky at different frequencies.

• Recording and storing high-speed data streams while also carrying out preliminary data processing and calibrations.

The choice of an SBC reflects a minimalist but highly effective strategy, perfectly aligned with space science’s emphasis on low-mass, high-capability payloads. Unlike traditional bulky systems, SBCs combine compactness, efficiency, and computational power, making them an excellent fit for space missions where size, weight, and power (SWaP) constraints are paramount.

Performance Breakthroughs in the Lab

Early performance tests have been highly promising. In experiments spanning 352 hours of data collection on a reference signal, the PRATUSH digital receiver achieved exceptionally low noise levels—just a few millikelvins. This degree of sensitivity is precisely what is needed to separate the faint Cosmic Dawn signal from background noise.

Researchers at RRI highlight that with further software enhancements and next-generation space-grade components replacing the commercial Raspberry Pi, PRATUSH will be well-positioned for deployment as a space-ready payload.

Voices from the Team

“SBCs, as scaled-down versions of desktop or laptop computers, deliver an appealing balance of size, performance, and efficiency to manage the data generated by FPGAs through software instructions,” explained Girish B. S., Research Scientist E, Electronics Engineering Group, RRI.

“The SBC is a critical component of the digital receiver system for PRATUSH, carefully selected to serve as both the master controller and data recorder,” added Srivani K. S., Research Scientist E, RRI.

“Technologies like the SBC-based digital receiver will be an integral part of payloads to detect the signal of the Cosmic Dawn from one of the quietest corners of the solar system,” noted Saurabh Singh and Mayuri S. Rao, Associate Professors of Astronomy & Astrophysics at RRI.

Toward the Future of Cosmic Exploration

By leveraging an unassuming yet powerful computing device, PRATUSH represents a leap forward in our ability to study the Universe’s earliest chapters. If successful, it may reveal how the first stars ignited, how they sculpted the intergalactic medium, and whether unknown physics played a role in shaping the early cosmos.

The prospect of a tiny computer orchestrating one of humanity’s most ambitious explorations underscores the evolving philosophy of space science: sophisticated discoveries do not always demand massive hardware—they can also emerge from elegant, compact, and cost-effective designs.

As PRATUSH moves closer to realization, it carries with it the promise of unraveling one of astronomy’s greatest mysteries—the Cosmic Dawn, the moment when the Universe first lit up.