RocketSTEM Issue #14 - March 2017 | Page 23

S.T.E.M. for the Classroom Original illustration by Meha Magesh meters AGL with a maximum Ground Distance of 600 meters downrange from the rover. These numbers will serve as our constraints for the MHS app. Scientists on Earth feed the MHS its flight information, and off it goes. The information given to the MHS consists of three parts: 1. Desired Altitude (in meters AGL) 2. Desired Ground Distance away from the rover (in meters) 3. Desired Hover Time (in seconds) The Rover and FTP form a right triangle, which can be solved easily using trigonometric and triangle identities! Example Scientists on Earth want the MHS to go to a FTP that is 400 meters downrange with an altitude of 100 meters AGL, and a hover time of 60 seconds so that the MHS can take a image of the rover. Find the Round Trip Dis- tance, Climb Angle, and Average Speed of the MHS. The maximum flight path capability of the MHS, with a maximum downrange distance of 600 meters and a maximum altitude of 120 meters AGL (Graph is NOT drawn to scale). Credit: S.T.E.M. For the Classroom We can use the Pythagorean Theorem to find the Distance to the FTP, which is the hypotenuse of the right triangle. The tangent ratio is used to determine the climb angle (in degrees). The Travel Time becomes the Flight Time Capacity minus the Hover Time. We can then use that information to calculate the average speed of the MHS. 21 www. RocketSTEM .org 21