Astronauts preparing for an international space mission are taking precautions to avoid bringing coronavirus to space, according to a report.

NASA’s Chris Cassidy along with Russian astronauts Ivan Vagner and Anatoly Ivanishin are prohibited from leaving the Star City training center outside of Moscow ahead of their April 9 mission to the International Space Station, the Telegraph reported.

Pavel Vlasov, who is head of Star City, said that astronauts and crew routinely go into quarantine ahead of missions to prevent infection, but the quarantine started “earlier than usual,” the outlet said.

They will also forgo the ceremonial tour that’s been customary ahead of space launches since 1961.

“The crews are not making any trips out, even such traditional ones as visiting the Kremlin wall and the house of Sergei Korolyov on the eve of departure for Baikonu,” Vlasov said in a statement.

The International Space Station is currently cleared of COVID-19. The last spacecraft carrying people docked in September.

The virus — which has infected more than 128,00 people worldwide — first emerged in December in Wuhan, China.