Scientists have developed a new approach to create highly combustible rocket fuel that is much cleaner and safer than the hypergolic fuels commonly used today.
The new fuels use simple chemical "triggers" to unlock the energy of one of the hottest new materials, a class of porous solids known as metal-organic frameworks, or MOFs.
MOFs are made up of clusters of metal ions and an organic molecule called a linker, according to the research published in the journal Science Advances.
"This is a new, cleaner approach to making highly combustible fuels, that are not only significantly safer than those currently in use, but they also respond or combust very quickly, which is an essential quality in rocket fuel," said Tomislav Frisci, a professor at McGill University in Canada.
Satellites and space stations that remain in orbit for a considerable amount of time rely on hypergols, fuels that are so energetic they will immediately ignite in the presence of an oxidiser.
The hypergolic fuels that are currently mainly in use depend on hydrazine, a highly toxic and dangerously unstable chemical compound made of a combination of nitrogen and hydrogen atoms.
Hydrazine-based fuels are so carcinogenic that people who work with it need to get suited up as though they were preparing for space travel themselves, researchers said.
Despite precautions, around 12,000 tonnes of hydrazine fuels end up being released into the atmosphere every year by the aerospace industry.
"Although we are still in the early stages of working with these materials in the lab, these results open up the possibility of developing a class of new, clean and highly tunable hypergolic fuels for the aerospace industry," said Hatem Titi, a post-doctoral fellow who works in Frisci's lab.