R
rogerinnh
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Unpowered Lunar Landing<br /><br />I’ve come up with what I think is a unique approach to landing on the Moon.<br /><br />Comments are welcome.<br /><br />The earliest Lunar touchdowns consisted of simple trajectories from Earth to the Earth-facing surface of the Moon and were not actually touchdowns but rather crash-intos. Subsequent to those early attempts the approach that has always been taken is to first go into Lunar orbit and then to de-orbit to a rocket-powered touchdown.<br /><br />But now consider the fact that the Moon is not a stationary object. It is revolving around the Earth in its orbital trajectory at approximately 3,291 feet per second (if my calculations are correct). Suppose that you had a space craft positioned along the Moon’s orbital trajectory, such that the Moon was moving away from the space craft. Now suppose that the space craft started at “just the right position” away from the Moon, along the Moon’s orbital trajectory, and was “dropped” towards the Moon. The space craft would accelerate towards the Moon (because of the Moon’s gravity), as the Moon was moving away from the spacecraft. If the space craft’s starting position and velocity were “just right” then the point in time and space where the space craft “caught up with” the Moon would be such that the velocity of the space craft would exactly equal the velocity of the Moon along its trajectory (i.e. 3,281 feet per second). The space craft would therefore “touch down” on the Moon’s surface at zero relative velocity, a perfect soft landing without any rocket power required.<br /><br />A similar possibility exists from the opposite direction. If the spacecraft is positioned along the Moon’s orbital trajectory such that the Moon is approaching the spacecraft then, given the appropriate initial velocity of the spacecraft, moving “away from” the Moon, along Moon’s orbital trajectory, the Moon would “catch up” to the space craft at just the right time and position such that the relative velocities b