The Kievan People wrote:I am not defending SSTOs.
But having an aerodynamic form makes sense if it is an SSTO, si?
I mean SSTOs are useful if you want something that can put small payloads into orbit and which has an extremely high launch rate. So say launching satellites or shuttling cargo to and from a space station. But for putting heavy payloads into orbit or interplanetary travel an SSTO doesn't make a huge amount of sense. Better to go with a massive, expendable multi-stage rocket or something like an NTR that has a super high isp (but a correspondingly low T/W), respectively
If it has to exit and re-enter the atmosphere it has to have a low drag coefficient and a high ballistic coefficient, so yes it does need to be aerodynamic. The shape will basically boil down to a lifting body with short stub wings (venturestar) or an ogival sears-hack shape (basically a missile) also with short stubby wings. In the case of the venturestar the wings are just there really only for landing since it takes off and climbs vertically whereas the sklyon needs its stubby wings to land but also to take off since the skylon would take off and land like a conventional plane. The skylon, due to its shape and super high ballistic coefficient, is also going to enter the atmosphere head on like a ballistic missile basically and use the lower atmosphere to decelerate whereas the flat underside of the venturestar, like the space shuttle, acts like a blunt body during reentry and is designed to decelerate mostly in the thin upper atmosphere. Basically two ways of doing the same thing, although the blunt body method places somewhat less heat stress on the object.