Orbit Essay

2131 Words9 Pages
Mankind’s destiny is amongst the stars. Space based industries such as asteroid mining could become the largest industries in the world with annual profits in the trillions of dollars within our lifetime. For any type of travel or work to be possible in space, an understanding of orbital mechanics is crucial. In space, all objects are in orbit of something. Satellites both manmade and natural orbit planets and moons. Moons orbit planets. Planets orbit stars, and stars orbit the center of galaxies. An orbit is the elliptical path an object follows when affected by gravitation. Basically that means that gravity from a big object such as a planet, pulls a smaller object, such as an asteroid, towards it, and as a result, the asteroid circles it. Why do objects in orbit circle the body that they are orbiting instead of just falling into it? Satellites do fall into the bodies that they are orbiting, but they are moving at such a high velocity, that they miss the object and are pulled around in an ellipse. To do so, objects must move extremely fast. An object in low Earth orbit must move extremely fast. The equation to find orbital velocity is v_orbit=√(rg_orbit ) meaning orbital velocity equals the square root of the orbital radius times the acceleration of gravity at that orbit. All systems with an object moving in uniform circular motion have two basic parts: a satellite velocity in a straight line, and a centripetal force pulling the linear velocity vector into a circle. The International Space Station orbits at an altitude of 460km and has an orbital velocity of 7.7km/s. That is about the length of the Mackinac Bridge in one second. It is a common misconception that there is no gravity in space. In fact, there is gra... ... middle of paper ... ... Any steeper, and the crew would be crushed by the G forces. That’s an error window of only 2.4 degrees. On top of the danger in the precision required, there is also the risk that the spacecraft could have been weakened sometime in the mission and could be torn apart by the intense deceleration. Or the heat shield could have been damaged and the spacecraft could burn up. Orbital mechanics might seem a bit overwhelming at first. It can seem counterintuitive and at times appears downright insane. I didn’t even touch the intense math involved in calculating the exact angles and timing in which maneuvers must happen. Or hoe the net result of every move affects the calculations of an entire mission. It is after all rocket science. However, if we are to move forward as a species and spread out from the fragile ball of earth, it is a skill that we need to master.