From Space News:
“The robotic Mission Extension Vehicle-1 (MEV-1) launched atop a Russian Proton rocket today (Oct. 9) from Baikonur Cosmodrome in Kazakhstan at 6:17 a.m. EDT (1017 GMT, 4:17 p.m. local Kazakhstan time).
MEV-1, which was built by Virginia-based company Northrop Grumman, launched along with the Eutelsat 5 West B communications satellite. If all goes according to plan, both spacecraft will deploy into a supersynchronous transfer orbit about 16 hours after liftoff. MEV-1 will then make its way to geostationary orbit and eventually link up with the Intelsat 901 communications satellite, which has been circling Earth since June 2001 and is low on fuel. Using its onboard electric thrusters, MEV-1 will take control of the pointing and orbit-maintenance duties for Intelsat 901 — something no other commercial satellite has ever done.”

Here is Northrop Grumman’s description of MEV: