For example , in 1999 the NASA Lunar Prospector orbiter was deliberately targeted to impact a permanently shadowed area of Shoemaker Crater near the lunar south pole .
Controlling the location of impact for spent lunar orbiters can have scientific value .
In 1999 the NASA Lunar Prospector orbiter was deliberately targeted to impact a permanently shadowed area of Shoemaker Crater near the lunar south pole .
Controlling the location of impact for spent lunar orbiters can have scientific value .