Tiny Computer to Aid India’s Hunt for Cosmic Dawn Signals

A compact single-board computer (SBC), no larger than a credit card, is poised to play a pivotal role in unlocking secrets of the Cosmic Dawn—the epoch when the first stars and galaxies began illuminating the universe. Developed by the Raman Research Institute (RRI), Bengaluru, this breakthrough is part of India’s proposed PRATUSH mission to the Moon, aiming to detect one of the faintest radio signals ever observed.

What Is PRATUSH?

PRATUSH (Probing ReionizATion of the Universe using Signal from Hydrogen) is a proposed lunar radiometer mission designed to study the 21-cm hydrogen signal—a weak radio signature emitted by neutral hydrogen atoms during the early universe.

This signal, if detected, could offer direct observational evidence of the Cosmic Dawn, an era roughly 13 billion years ago when the first stars and galaxies began to form.

Why the Moon?

On Earth, this hydrogen signal is buried under heavy radio interference, including,

• FM transmissions
• Ionospheric distortions

Hence, the far side of the Moon, considered the most radio-quiet region in the inner solar system, is seen as the ideal observational site for such sensitive measurements.

The Role of the Single-Board Computer

Traditionally, space instruments rely on bulky and power-hungry controllers. But researchers at RRI’s Electronics Engineering Group have developed a lab-scale digital receiver powered by a lightweight single-board computer, which,

• Coordinates antenna, receiver, and FPGA chip
• Records, stores, and pre-processes incoming radio data
• Carries out system calibration
• Offers high efficiency with low power usage

According to Girish B.S., Research Scientist at RRI, the SBC strikes the right balance between size, power, and performance, essential for lunar space applications.

Promising Test Results

The system was tested over 352 hours using a reference signal, achieving,

• Noise reduction down to millikelvin levels
• High sensitivity to weak signals
• Stable performance under continuous operation

These tests confirm the suitability of the SBC-based system for space-based radiometry.

Future Potential and Next Steps

The RRI team plans to,

• Upgrade to space-qualified SBCs
• Enhance software for onboard AI-enabled processing
• Integrate the system into a compact payload for lunar deployment

If successfully launched, PRATUSH could mark a milestone in India’s space science efforts, providing insights into,

• Formation of the first cosmic structures
• Evolution of the early universe
• Potential new physics beyond current cosmological models