What is the range of weapons if used in space?

Category: Space
Published: February 16, 2013

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and physics professor at West Texas A&M University

Weapons in space would have an effectively infinite range. On earth, gravity inevitably slams bullets, missiles, rockets, mortars, and bombs into the ground. As a result, every weapon has a characteristic range limit beyond which it can not reach. In outer space, there is still gravity, but an object is so far away from planets that the gravity just deflects an object's path rather than slamming it into the ground. As a result, weapons in space have effectively unlimited range. A rocket fired in space will coast forward indefinitely under its own momentum long after its engines have turned off. If the conditions are just right, the missile may end up in orbit around a distant planet (after decades of traveling). But space is so big that a weapon fired from interstellar space will most likely miss the strong gravity of planets and stars and coast in a straight line until the end of time, just as the Voyager space probes have been doing for the last few decades. Laser beams likewise would travel indefinitely. This fact is made obvious by the experience of viewing the light that has traveled from stars at the edge of the observable universe. The light may be weakened by interstellar dust, but the effect takes years to become effective. Missiles and laser beams fired in space do not suddenly disappear, blow up, or stop when they have reached some range limit as shown in movies.

Weapons fired in space would have effectively infinite range as there is very little friction to slow them down. Public Domain Image, source: NASA.

Topics: momentum, space movie, space weapons, space weapons range