Q&A with Kurt Eberly, Orbital ATK’s Antares deputy program manager

A SpaceX Falcon 9 launcher boosted a 4.7-ton military-grade communications satellite for SES and the Luxembourg government toward a perch 22,300 miles over the equator following a spectacular late afternoon liftoff Tuesday from Florida’s Space Coast, clearing the last mission off the launch company’s manifest before the long-awaited debut of the massive Falcon Heavy rocket.

Orbital Sciences Corp. and Energia have signed a contract worth approximately $1 billion for up to 60 Russian-made RD-181 rocket engines to power the redesigned first stage of the commercial Antares launcher.

On the eve of the Iridium’s fifth launch with SpaceX, the mobile telecom satellite operator’s chief executive says he no longer waits for SpaceX’s rockets to be ready. Instead, Iridium’s satellite team is racing to keep pace churning spacecraft off their assembly line.