Video: Liftoff of Atlas 5 on NROL-55

An unmanned cargo freighter carrying nearly four tons of supplies and science, launched and operated commercially for NASA, blasted off from Cape Canaveral on Tuesday atop an Atlas 5 rocket bound for the International Space Station.

Despite a growing number of rocket options, the availability of on-time launch services remains a key factor in getting BlackSky’s constellation of Earth-imaging smallsats into orbit. SpaceX’s rideshare launch service will give BlackSky a chance to add two more spacecraft to its fleet on a Falcon 9 rocket with the next batch of Starlink Internet payloads.

A Chinese Long March 2D rocket carried four “technology experiment satellites” into orbit Wednesday from the Xichang space center in southwestern China, according to the country’s state-run media.