The Missions Undone by One Small Thing
A team that calculated in pounds, a switch installed backward, a flake of paint the size of a comma, and a lens cap left under the arm that was supposed to test the ground.
The spacecraft was fine. The arithmetic, the switch, the speck of paint, or the cover lying on the soil was not. In 1999 a Mars probe arrived and was never heard from again, because one team had worked in pounds and the other in newtons. In 2004 a capsule full of solar-wind samples hit the Utah desert because a switch had been installed backward. A flake of paint the size of a comma left a billion-dollar telescope nearsighted. The machine, every time, did what the small error told it to do.
The Mars Climate Orbiter reached Mars on September 23, 1999. Ground software had reported its thruster firings in pound-force seconds. The navigation software expected newton-seconds, and the $125-million spacecraft was lost. Genesis came home on September 8, 2004. The parachute never opened. The capsule hit the Utah desert at 193 miles an hour because the gravity switches that were supposed to open the parachute had been designed backward. Investigators walking into a test chamber in Danbury in the summer of 1990 found the flake of black paint, about the size of a comma, missing from a cap on the instrument used to test the Hubble mirror. The mirror was then polished to match the wrong template. Mariner 1 was blown up four minutes and fifty-four seconds after launch. The missing mark in the guidance equation was an overbar, a line drawn above a letter, which the newspapers filed as a hyphen. On 5 March 1982, Venera 14 survived the clouds of Venus, swung out an arm to test the ground, and punched its own lens cap. On June 3, 1966, Gemini IX-A reached its docking target and found the nose cover hanging open in two halves. The bolts had fired. The lanyards that were supposed to pull the connectors free had been taped down.
This page is the shelf those small things share. Start here for the Mars Climate Orbiter, and for the longer record of flights undone by a mark, a switch, or a speck.
- The Docking Target That Showed Up in Orbit Looking Like an Angry Alligator
- The Flake of Chipped Paint That Made a $1.5 Billion Telescope Nearsighted
- The Most Expensive Hyphen in History Was Not a Hyphen
- The Venus Lander That Tested the Hardness of Its Own Lens Cap
- The Unit Mix-Up That Doomed a Mars Probe
- The Genesis Capsule That Crashed Because a Switch Was Installed Backward