Cow Waste Transformed Into Biomethane for Rocket Engine: Fuels Japan’s Sustainable Space Propulsion

In 2017, a Kolkata-based company launched cheap, environmentally friendly buses running cow manure biogas. After several years, a Japanese start-up has taken this step further by adopting the same technology to power space rockets.

From Pasture to Payload

On December 7, Japan's space industry opened a potentially new chapter by testing a prototype rocket engine that runs entirely on fuel derived from cow dung. The engine blasted a blue-and-orange flame 30-50 feet (10-15 meters) horizontally from an open hangar door for 10 seconds in Taiki. The liquid biomethane required was made from gas derived from cow waste sourced from two local dairy farms.

According to Interstellar Technologies chief executive Takahiro Inagawa, this effort was made because a sustainable energy source is good for the environment. In addition, this type of biomethane is very cost-effective, can be produced locally, and has a high performance and purity.

Hoping to use this kind of fuel to put satellites in space, Interstellar collaborated with industrial gas producer firm Air Water. The company works with local farmers with farm equipment to process cow manure into biogas. The Air Water collects this biogas and turns it into rocket fuel.

Due to poor resources, the country needs to secure domestically produced, carbon-neutral energy. Raw material from cows has much potential to secure Japan's energy source if some changes happen in international affairs.

A local dairy firm and other factories are already using the biomethane from Air Water. It is also used to heat local homes and run trucks and ships.

Last September, Japan's space agency, JAXA, launched its "Moon Sniper" mission to land on the near side of the moon, making Japan the fifth country to touch down safely on the lunar surface. The mission aims to rebound from previous setbacks and strengthen its space exploration programs.

The country's launch rockets suffered setbacks when encountering liftoff mishaps in its next-generation H3 and the solid-fuel Epsilon. Meanwhile, the Epsilon S rocket test ended in an explosion 50 seconds after ignition.

The successful test of the new cow-dung-powered rocket engine offers a promising new chapter for Japan's space program. It also provides a potential solution for the increasing global energy crisis.

Utilizing the Potential of Biogas

Biogas refers to a flammable gas made from the digestion of organic materials like kitchen waste, cow manure, and industrial effluent. This technology involves supplying a manure digester with feedstock, which will be converted into methane. The anaerobic digestion produces biogas of 50-70% methane and 30-50% carbon dioxide, with trace amounts of hydrogen sulfide and other gases.

Biogas from cow dung is already being used for fuel around the world. It helps mitigate the environmental footprint of agriculture, which is attributed to 14% of global greenhouse gas emissions. While burning biogas also releases greenhouse gases, they are left to degrade naturally, unlike runoff from farm animals, which pollutes soil and waterways.