1999 – Mars Climate Orbiter Lost. Mars Orbit Insertion (MOI) was to occur at an altitude of 140 km but hours before the MOI bipropellant engine burn the JPL team worried about a navigation error that was bringing the orbiter to a 57 kms altitude, 83 kms beneath the intended orbit. Later analysis found that a navigation error occurred when a translation from Imperial units to Metric units was incorrect.
“The desaturation of the reaction wheels does impart a small force on the spacecraft, and has to be accounted for in the navigation. Lockheed Martin, which built the Mars Climate Orbiter spacecraft, provided the reaction wheel data to the JPL navigators. JPL does its navigation work exclusively using the metric system, and Lockheed was required to provide the data in metric units. They instead provided the data in imperial units. Even though the force of the desaturation of the reaction wheels was small, desaturations were done frequently during the cruise period of the orbiter (~9 months), and the error from using imperial units accumulated over time. Also, JPL does share in the blame for the loss of the orbiter, as JPL should have detected the use of imperial units by Lockheed.” (Ron Baalke)
Birthdays
1930 – John Watts Young was born in San Francisco, California. Selection: NASA Group 2 (1962) Time in space: 34d 19h 39m. EVAs: 3, 20 hrs, 14 mins. Missions: Gemini 3, Gemini 10, Apollo 10, Apollo 16, STS-1, STS-9
Young served as Chief of the Astronaut Office from 1974 to 1987, and retired from NASA in 2004, after 42 years of service. (d. 5 January 2018)
