Expiring medications could pose problem for Mars astronauts

French astronaut Thomas Pesquet onboard the International Space Station. Medicines used on the ISS are likely to make up the bulk of a medical kit for a Mars mission. Photograph: Nasa/Reuters

When it comes to crewed missions to Mars there is no shortage of hazards, from space radiation to a hostile environment. Now researchers have found another snag: many of the medicines astronauts may take with them are likely to expire before they return to Earth.

Researchers say they have discovered a host of medications used in space have a shelf life of three years or less – a problem given Nasa expects a mission to Mars to take roughly 36 months.