Like most NRO missions, details of the payload are classified; however, information that has been made public leaves little doubt that it is an electronic signals intelligence (ELINT) satellite bound for geostationary orbit. From this high perch, the satellite will intercept radio signals from terrestrial sources and relay them back to the NRO for analysis.
The NRO’s geostationary ELINT satellites are part of a series known as Orion, which began with the deployment of the USA-8 spacecraft from the Space Shuttle Discovery during 1985’s STS-51C mission. The first two satellites were launched aboard the Space Shuttle, the next three by Titan IV rockets, with the Delta IV Heavy having been used since 2009. The NROL-70 mission will be the 17th Delta IV launch for the NRO — 12 of which have used the Delta IV Heavy — and the seventh time an Orion satellite has launched aboard a Delta IV.
ULA Launch Director Tom Heter III has instructed the launch team to coordinate a new liftoff time of 2:45 p.m. EDT (1845 UTC) for the Delta IV Heavy rocket on the NROL-70 mission from Cape Canaveral tonight.