A Delta IV Heavy rocket, operated by the United Launch Alliance (ULA) launched the NRO L-82 payload into orbit on behalf of the US National Reconnaissance Office. The launch took place from Vandenberg, California at 2047 GMT on 26 April 2021. The Delta IV Heavy consists of a core stage “common core booster” and upper stage with two large strap-on “common core boosters”. Each of the common core boosters is powered by an Aerojet Rocketdyne (AR) RS-68A liquid oxygen (LOx)/liquid hydrogen engine. The second stage was powered by an Aerojet Rocketdyne RL10B-2 liquid oxygen (LOx)/liquid hydrogen engine. In many ways, the launch vehicle is the “greenest” of launch vehicles – at least for the launch itself in producing just water vapour as the propellants burn.
US Space Command does not release satellite orbit details for its military satellites. However, amateur observers report that the payload is in a 758 x 525 km Sun-synchronous low Earth orbit inclined at 98 degrees. According to the reports promulgated by orbital expert Jonathan McDowell, the orbit has an “early afternoon” crossing time with a 1300 local time of descending node. The spacecraft is believed to be a high resolution KH-11 (Crystal) reconnaissance satellite.