while the x-34 cannot be described as a true spaceplane , since it has an expendable upper stage, if it is successful it will provide unassailable evidence for the feasibility of a true spaceplane .
虽然x—34因为具有一个消耗性上部一级火箭而不能被认为是一架真正的太空飞机,但如果它成功了,那将为人们制造出真正的太空飞机提供无懈可击的证据。