Not much bigger than a shoebox, checking progress of the tiny six-wheeled buggy set records for hit rates for the site, demonstrating the public popularity of Mars. The last pair of Mars missions sent by Nasa were anything but successful. The Climate Orbiter probe was lost in September 1999 when it plunged into the Martian atmosphere, owing to a misunderstanding between project teams regarding the rocket burn required to insert it into orbit. One group had used imperial units, the other metric. Three months later the Polar Lander probe was also a failure, contact being lost as it approached touchdown close to the south pole of Mars.
Critics argue that the history of Martian exploration has been littered with such failures.
During the 1960s and 70s a dozen Soviet satellites were either lost completely, or returned very limited data. In 1988 radio contact with two further missions was lost during their cruise towards Mars. Another Russian satellite, including experiments contributed by various European nations, suffered a launch malfunction in 1996. Japan launched its Nozomi probe to Mars in 1998, but a propulsion problem has delayed its arrival until late in 2003. The Americans may have suffered similar setbacks, but their successes have radically altered our view of the Red Planet.