Shannon Lucid gives a guided tour of the Mir space station

A Blagovest communications spacecraft lifted off Monday aboard a Proton rocket to complete a network of four relay satellites in geostationary orbit for the Russian military. The Proton rocket’s Breeze M upper stage successfully delivered the Blagovest spacecraft to its intended orbit nine hours later.

Engineers are troubleshooting a small air leak aboard the International Space Station that was discovered last September, NASA reported Thursday. While it poses no safety threat, the lab’s three-man crew plans to seal themselves in the Russian segment of the station this weekend to help engineers pin down the leak’s location.

Russian ground crews working in starkly different environments on the barren steppes of Kazakhstan and in the lush jungles of South America are readying a pair of Soyuz rockets for two launches Thursday, one to resupply the International Space Station, and another to broaden the capacity of SES’s O3b Internet network.