Travelers In The Night

Spacecraft destined for Mars have so far used the Hohmann transfer to achieve an orbit about the red planet. This approach requires the launch from Earth orbit to be in a small window in time which becomes possible every 26 months. When the spacecraft gets near Mars retro rockets, which require hundreds of pounds of fuel, must be fired to slow it so that the spacecraft so that it does not exceed orbital speed. To make the trip to Mars orbit cheaper and more reliable a new technique has been theorized and then tested on Moon flights. It is called ballistic capture.