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

Riding a half-million pounds of thrust, a Minotaur 4 rocket fired off a launch pad in Virginia, surpassed the speed of sound in less than 20 seconds, and vaulted into orbit Wednesday with four classified payloads for the National Reconnaissance Office.

The launch of a United Launch Alliance Delta 4-Heavy rocket from Cape Canaveral was aborted three seconds before a planned liftoff at 3:28 a.m. EDT (0728 GMT). The rocket was set to loft a classified payload for the National Reconnaissance Office, the U.S. government’s spy satellite agency.

The European-built Solar Orbiter spacecraft was installed on top of its United Launch Alliance Atlas 5 launcher Friday at Cape Canaveral, ready for final charging and checkouts before liftoff Feb. 9 to finally begin a more than $1.5 billion science mission first approved by the European Space Agency nearly 20 years ago.