In Connect, the Update segment's spacecraft properties are divided into Action and Val attributes. The Val attributes define the values that the Action attributes will apply to the spacecraft.
Astrogator <Satellite Object Path> SetValue <Attribute Path>.Update.{Val Attribute} <Value> [{Unit}]
Spacecraft properties are defined by the following Val attributes :
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Update.DragAreaVal 10 m^2
STK Programming Interface 11.0.1