A section of a ROCKETvehicle that is cast off and separates from the vehicle during flight, especially a section that falls back to EARTH.
在飞行过程中从火箭运载工具上与其脱开和分离的部分,特别是掉回地球的一部分。
2
Combining a rocket, a jet and a racing-car engine into one vehicle is engineering of an extreme sort, but record-breaking often demands that new problems be solved.
Hydrogen is "just about the worst possible vehicle fuel", says Robert Zubrin, a rocket scientist and the author of "Energy Victory", a book on the post-petroleum future.