In mainstream science, Vallée is notable for co-developing the first computerized mapping of Mars for NASA and for his work at SRI International on the network information center for the ARPANET, a precursor to the modern Internet. Vallée is also an important figure in the study of unidentified flying objects (UFOs), first noted for a defense of the scientific legitimacy of the extraterrestrial hypothesis and later for promoting the interdimensional hypothesis.In May 1955, Vallée first sighted an unidentified flying object over his Pontoise home. Six years later in 1961, while working on the staff of the French Space Committee, Vallée witnessed the destruction of the tracking tapes of an unknown object orbiting the earth. The particular object was a retrograde satellite – that is, a satellite orbiting the earth in the opposite direction to the earth's rotation. At the time he observed this, there were no rockets powerful enough to launch such a satellite, so the team was quite excited as they assumed that the Earth's gravity had captured a natural satellite (asteroid). A superior came and erased the tape. These events contributed to Vallée's long-standing interest in the UFO phenomenon.
