Scientists said they launched the satellite from midair to save money, compared with an expendable rocket launched from the ground, because it doesn't take as much fuel to break free of the planet's gravity.

WSJ: NASA NuStar Telescope to Hunt for Black Holes

The most obvious one was the cancellation earlier this year of NASA's Constellation program, which was intended to provide a "man-rated" expendable rocket to replace the shuttle as America's means of putting humans into space.

CENTERFORSECURITYPOLICY: Farewell to space