Orbit Simulator

By Mark Pellegrini

Instructions

• This program is meant to simulate the orbital motion of objects in space. There are two types of objects involved in the simulation, "heavy" objects and "light" objects. Heavy objects are very massive. For the purposes of the simulation, they are too massive to be influenced by the gravitational pull of any other objetcs. Light objects, on the other hand, are affected by the pull of any nearby heavy objects. The simulator works by first adding and positioning the "heavy" objects in space, and then launching "light" objects at them. The "light" objects will be affected by the gravity of the "heavy" objects and their paths will be influenced as they would in the real universe. Using this tool, one can easily simulate how bodies will react in space.

• To add a heavy object to the field of view, right click on empty space and slect "Add Heavy Object" from the context menu. The object will appear in that location.
• To remove a heavy object, right click on it and select "Remove Object" from the context menu. The object will be deleted.
• To move a heavy object, you may click and drag it to any position in the field of view.
• To change a heavy object's properties, left click it to select it. You may then use the sliders on the lower pane to change the object's position, mass, and radius.
• NOTE: When no object is selected, the sliders in the bottom panel are not active and cannot be used.

• To add a light object to the field of view, first select the "Launch Mode" button in the bottom panel. The button will turn green indicating that launch mode is active. The words "LAUNCH MODE ENABLED" should also appear in red in the upper left corner of the field of view.
• Once launch mode is enabled, move the mouse onto the field of view. You should see a small object following the mouse. Bring the mouse to the place where you want to launch the object from. Click and hold the left mouse button and drag the mouse in the direction you want to launch the object. A line will appear between the starting location and your current mouse position. The magnitude of the line indicates the speed at which the object will be launched. A number will also appear next to your mouse, indicating the initial velocity of the object. Release the mouse to launch the object.
• As long as launch mode is enabled, you can repeat this process as many times as you want. To cancel launch mode, click the button in the bottom panel again.

• After an object is launched, its flight path will be affected by the heavy objects that you placed. You can modify, add, or remove heavy objects while there are objects orbiting them by switching out of launch mode.
• You will see the light objects orbiting the heavy objects. If the orbit cannot be sustained and the light object crashes into the heavy object, it will stop and get stuck there.
• The light objects will leave a short trail behind them to aid in seeing the flight path of the object.
• To remove all of the light objects and start over, click the clear button in the bottom panel. This will not remove the heavy objects you placed.