Mars Climate Orbiter

The Mars Climate Orbiter was launched at Cape Canaveral, Florida, on December 11, 1998. It was going to be the first ever "weather" satellite for Mars. It would also relay information for the Mars Polar Lander. The spacecraft's main body was 2.1 meters tall, 1.6 meters wide, and 2 meters deep. The wing span of the solar array was 5.5 meters from tip to tip. The spacecraft weighed 629 kilograms including 338 kilograms of fuel. The Mars '98 Project cost $193.1 million for spacecraft development, $125 million for the orbiter, $202.6 for the lander, $91.7 million for the launch, and $42.8 million for mission operations.

"The problem is sometimes little things can really come back and make a big difference, and that's the case we have today."

-Arthur G. Stephenson, Director

Marshall Space Flight Center

The Mars Climate Orbiter failed because the rules were not followed. In most scientific calculations the metric system is used. For the Mars Climate Orbiter, the Jet Propulsion Laboratory (JPL), used the ground software file, "Small Forces." Lockheed Martin wrote the software program using U.S. Customary units, when it should have been in metric units. During the nine month trip from Earth to Mars, the pressure on the Mars Climate Orbiter's solar array caused the Orbiter to twist. To correct this, the Orbiter had to be adjusted ten to fourteen times a week. Using the wrong units in the corrections, put the Orbiter on the wrong trajectory. The navigation team thought the Mars Climate Orbiter was about 110 kilometers above the surface of Mars. The closest the Orbiter could get to the Martian surface without being destroyed was about 93 kilometers. In reality, the Orbiter was only 57 kilometers above Mars. That's a big difference in U.S. Customary or metric! The Mars Climate Orbiter probably did not survive.

2.1

5.5 meters

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The solar array of the Mars Climate Orbiter from tip to tip is the same length as a fifteen passenger van. The van is also the same height and width as the Mars Climate Orbiter's main body. Imagine trying to control a van-sized spacecraft that is heading for Mars 255.2 million kilometers away!