Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

The launch of the SES O3b mPOWER satellites a day after the Transporter-9 rideshare mission from California. The Boeing-built O3b mPOWER 5&6 satellites launched from Space Launch Complex 40 (SLC-40) at the start of the 89-minute window that opened at 4:08 p.m. EST (2108 UTC).

Four magnetic explosion probes in a towering stack atop an Atlas 5 rocket rode a fountain of flame off the launch pad and into Earth orbit Thursday night for a $1.1 billion NASA science investigation into a universal force of nature.

The Antares rocket, Orbital ATK’s medium-class booster now with modern RD-181 engines, launches at 7:45 p.m. EDT (2345 GMT) from NASA’s Wallops Flight Facility on the eastern shore of Virginia.