The Soviet Union loses contact with the Phobos 1 unmanned Mars probe during its interplanetary flight and is unable to re-establish contact. The cause of the vehicle’s loss is later traced to a typo in a single line of command code uplinked to its computer from the ground; this error changes a routine command to a command to shut down attitude control, leaving Phobos 1 tumbling through space, unable to point its antenna toward Earth. The mission is a complete loss.
