NASA's Mariner 1 aborted due to dodgy programming

The Mariner 1 had a silly little problem.

Satellites are quite complex devices, and owing to the nature of them they're a not insignificant amount of expense and effort to both build and launch them into orbit. Indeed when they're actually in orbit there can still be problems; but when the Mariner 1 was launched on July 22 1962 it was pure human error.

The Mariner 1 was intended as the first of the Mariner missions, with a Venus flyby on the itinerary and the possibility of other monitoring after the fact. Thrust systems were checked, onboard devices checked and even the data telling it which part of space to aim for was checked.

In fact almost every single part of the Mariner 1 was inspected with a fine-toothed comb before launch. Everything, that is, except the programming. The official statement was that a missing hyphen from the code that ran the guidance system caused the satellite to veer wildly off-target, but there was an unofficial mention that the computer equations that steered the satellite were incorrect.

Either is just as likely, and the result was an incorrect flightpath of the satellite as it wove erratically through the air. Whatever the cause for the error, the Mariner 1 was detonated after 293 seconds (just under five minutes), and the burning shell of the Mariner 1 fell back to Earth.

A few months later the Mariner 2 was sent out into space, and the errors had been corrected, leading to the eventual successful launches of ten Mariner satellites total. It's quite interesting to see just how a single thing can be so destructive, so check out Wired's writeup of the Mariner 1.