Russian cosmonauts have discovered a minor air leak from the Soyuz spacecraft docked with the International Space Station (ISS) using an ultrasound device, after having attached the second patch.

The crew's radio exchange with Earth, broadcast by a NASA resource, indicates that, having applied the second layer of a sealing compound, the cosmonauts recorded a minor leak, which stopped some time later.

The cosmonauts are planning to apply a third patch several hours later and are currently monitoring the situation.

It had been reported earlier that air pressure inside the Soyuz MS-09 spacecraft started lowering on Thursday. The cosmonauts increased pressure by 10 mm of mercury by pumping air from tanks of a Progress cargo spacecraft docked with the ISS.

On Thursday evening, the cosmonauts filled the cracks earlier discovered in the spacecraft's walls with a sealing compound and covered them with patches. It was reported that an ultrasound test showed no air leak at the time.