This hasn't been the best of summers for the International Space Station (ISS), with spacesuit issues in June cutting a spacewalk short, a software glitch in July in a recently docked lab knocking the ISS off course, and now the station's structural integrity being brought into question after a recent inspection.

Russian cosmonauts have discovered new cracks in a segment of the ISS that could widen, a senior space official said on Monday, the latest in a series of setbacks.

"Superficial fissures have been found in some places on the Zarya module," Vladimir Solovyov, chief engineer of rocket and space corporation Energia, told RIA news agency. "This is bad and suggests that the fissures will begin to spread over time."

He did not say if the cracks had caused any air to leak.

The space official has said previously that much of the station's equipment is starting to age and has warned there could be an "avalanche" of broken equipment after 2025.