for free

Now thrust could be generated (for “free” again) at periapsis, progressively increasing the altitude of apoapsis.

这时可以「免费」在近心产生推力，渐渐将远心度提升。

If I were Wang.I would play 2 more seasons, and stickit up the a$$ of Yankee management when he is eligible for free agency.

如果我是王建民，那我再投个二个球季，我变成自由球员时，我再来跟洋基敲上他一大。