The only existence of a Siloe space probe (or "secret space probe" as one website has it) is the Internet. No such probe exists. It does however serve as a way to rehash an old IRAS (infrared astronomy observatory) story which is not true.
"I sent an email to the two astronomers asking what happened back in '83. Gerry Neugebauer replied, and told me the real poop. IRAS was designed to look in the far-infrared, well past what our eyes see. At the time, no one was really sure what it would find. To everyone's surprise, several bright point sources were found that did not correspond to anything seen on optical images taken of the same areas. In the press conference, the two scientists said that these objects could be almost anything, from a tenth planet in our solar system to distant galaxies. Guess which it turned out to be? Sure enough, much deeper images were taken, and some of the objects were found to be dense gas clouds in our own Galaxy, while others turned out to be very distant galaxies. In fact, these observations heralded the discovery of a new type of object: Ultra-luminous Infrared Galaxies (ULIRGs)." -- Phil Plait
http://www.badastronomy.com/bad/misc/planetx/science.html#iras