H
ave you ever gotten lost while using the navigation services of your smart phone? You entered in your destination, Siri told you she had you covered, and all of a sudden you were on the wrong street or in the wrong neighborhood or wrong town? Well, Siri had a bad signal. This excuse may seem reasonable, at least until you compare Siri to NASA scientists on the Voyager program. These scientists have kept track of a vehicle the size of a compact car for over 30 years as it has traveled more than 11 billion miles towards interstellar space, all with orders of magnitude less computing power and memory than you have in your calculator or that smartphone.
sent to and received from a series of large antennas called the Deep Space Network. The network has antennas in the Goldstone Complex near Barstow, Cali., as well as in complexes near Madrid, Spain and Canberra, Australia. These locations are approximately 120 degrees apart so that at any time, at least one of them is facing the deep space probe. Three times a day, communication with the probe is switched as each antenna turns away and out of range.
Our planet also has a translational component to its movement as it rotates around the sun at 18.6 miles per second. Our varying location in our orbit sometimes results in the sun getting in our way. If we are on one side of the sun and the probe is on the Traveling at approximately 8 miles per other, we cannot send radio waves second, the Voyager 1 space probe is through the massive star. We may get currently in the outermost layer of the trapped out of touch with our probe heliosphere, the region of space domi- for months at a time, but we use our data and knowledge of astrophysics to nated by the sun, and will probably calculate where Voyager should be so be the first manmade object to leave the solar system. Designed to expand that when we return to a proper position, we can find it again. our knowledge and understanding of our solar system, Voyager has sent us thousands of pictures of Jupiter’s Putting it all together, as we spin at moons and Saturn’s rings, and the 1000 miles per hour and rotate around first “family portrait” of the sun and the sun at 18.6 miles per second planets. Though it is no longer sending with periodic interruptions by a giant photographs, Voyager is still sending sphere of hot plasma, we keep track us data about the far edges of our of an object that speeds away at 8 solar system such as the properties miles per second, billions of miles of magnetic fields in the regions apaway to the edge of our solar system, proaching interstellar space, the space all with technology from before the between star systems. days of cell phones or even compact discs. These days, a consumer has infinitely more information at his fingerSo how do we keep track of a hunk tips with the internet, smart phones, of metal as it speeds deeper into the and computers. depths of the unknown? If it sounds simple, remember that our point of It makes you feel a little silly for letreference, the earth, is spinning at 1000 miles per hour. We communicate ting Siri get you lost within your own planet, doesn’t it? with Voyager through radio waves