Sniffing out hydrogen in space

Scientists from Intelligent Optical Systems and Boeing have successfully demonstrated the world’s first fibre optic hydrogen leak detection system.

Scientists from Intelligent Optical Systems and Boeing have successfully demonstrated the world’s first fibre optic hydrogen leak detection system during a static fire test on a Delta IV orbital rocket at the NASA Stennis Space Centre.

The sensor is composed of a low-cost light source, standard telecommunications-grade optical fibre as the transmission medium and optrodes with temperature sensitive indicators.

‘By using optoelectronic sensors instead of electrochemical technology, we enjoyed several distinct advantages,’ said Reuben Sandler, President and Chief Executive Officer of IOS. ‘First, since optical sensors require no power at the sensing point, there is no danger of faulty wiring causing a spark. Second, these sensors are immune to electromagnetic interference and operate effectively in a wide variety of media

‘Third, optical fibre is flexible and resistant to temperature extremes and many caustic chemicals. Clearly, optical sensors are superior to the current technology utilising electrochemical sensors connected to multiple monitoring units by copper wiring.’

Sandler explained that liquid hydrogen is used as fuel in virtually all orbital rockets because of its efficiency and relatively low weight and that NASA has a critical need for a methodology capable of detecting leaks from cryogenic tanks and tubing containing high-energy propellants.

‘The sensor system, which utilises optical transduction technology, logs and processes data based on real-time inputs and stored calibration parameters. The sensor outputs are displayed instantaneously to facilitate immediate corrective actions.

‘Multiple sensors are linked together to monitor a wide variety of critical points, and the innovative design allows the sensors to be effective in demanding operating conditions and confined spaces,’ Sandler added.

Sandler anticipates commercial opportunities arising in hydrogen fuel markets such as micro or portable fuel cells, vehicular fuel cells and stationary fuel cells.