“a single character was missing”

In their book about the New Horizons mission to Pluto authors Alan Stern and David Grinspoon go on at length about the proofreading, troubleshooting, and rehearsals required for the mission. Nothing was checked just once — or just twice. Everything had to be gone over again and again. 

At times the failed attempts to explore Mars have made that planet seem cursed. Yet the authors want you to know that Mars didn’t do anything — we fucked up. Cognizance of that history deeply informs all planetary missions.

The history of space flight is replete with … tragic examples of … accident[s caused by seemingly tiny errors]. NASA’s Viking 1 Lander, the first successful Mars lander, had been lost six years after it touched down on the Martian surface, when a software update, meant to correct a battery-charging error, had accidentally included commands to redirect the communication dish. The errant commands pointed Viking 1’s dish antenna at the ground, where it could no longer communicate with Earth, and just like that - the mission was over. Similarly, Russia’s Mars probe called Phobos 1 was lost in 1986 when a single character was missing from a software upload. This minuscule mistake caused the spacecraft to deactivate its attitude-control thrusters; as a result its solar panels could no longer track the Sun, and the batteries lost all their power. It was never recovered. And in one of the most painful and embarrassing failures in the history of spaceflight, NASA’s Mars Climate Orbiter came in too low as it approached Mars in 1999, burning up in the atmosphere. The problem was traced to the fact that two groups of engineers had used different sets of units when computing the Mars orbit insertion maneuver: one engineering group had been using imperial units (feet and pounds), while the other group had been using metric (meters and Newtons).

All that checking and rechecking paid off for the New Horizons mission and we have amazing close-up views of a world we can barely see from Earth. 

source:

Chasing New Horizons: inside the epic first mission to Pluto

Alan Stern and David Grinspoon

2018. Picador, New York