Exploration of Mars failed upon impact. Mars 4 flew by the planet at a range of 2200 km returning one swath of pictures and radio occultation data, which constituted the first detection of the nightside ionosphere on Mars. Mars 7 probe separated prematurely from the carrying vehicle due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) and missed the planet by . In 1964, NASA's Jet Propulsion Laboratory made two attempts at reaching Mars. Mariner 3 and Mariner 4 were identical spacecraft designed to carry out the first flybys of Mars. Mariner 3 was launched
Mars 2 of entry was too steep. The descent sequence did not operate as planned and the parachute did not deploy. The descent module became the first man-made object to impact the surface of Mars. The exact crash site is unknown, but it is estimated to be at . Attempts to contact the probe after the crash were unsuccessful. Mars 2 The Mars 2 was an unmanned space probe of the Mars program, a series of unmanned Mars landers and orbiters launched by the Soviet Union May 19, 1971. The Mars 2 and Mars 3 missions consisted of identical spacecraft, each with