What kind of fuel do spacecraft use to explore the outer solar system and beyond?
Larry Owen
Jamul, California
Sir Isaac Newton’s first law of motion states that an object at rest stays at rest and an object in motion stays in motion with the same speed unless acted upon by an outside force. And in space, the only thing to slow down a spacecraft is gravity.
Before a spacecraft is even launched, scientists work out precisely where planets and other bodies will be to determine how the