Photos: Atlas 5 on the pad for X-37B launch

Delivering two-and-a-half million pounds of ground-shaking thrust at takeoff, more than any rocket flying from Cape Canaveral these days, the mighty vehicle was rolled from its assembly building to the launch pad Monday for Wednesday’s early morning blastoff.

The first piloted test flight of Boeing’s CST-100 Starliner commercial crew capsule has been delayed to early 2018 as designers wrestle with the mass of the spacecraft, aerodynamic loads the vehicle will see during launch, and new software requirements levied by NASA, company officials said.

Falcon Heavy is returning to the hangar and the launch of the USSF-52 mission with the X-37B spaceplane is on hold. A ground issue scrubbed an earlier launch attempt and now required work on the vehicle itself.