As a result, JPL engineers mistook acceleration readings measured in English units of pound-seconds for a metric measure of force called newton-seconds.
In a sense, the spacecraft was lost in translation.
"That is so dumb," said John Logsdon, director of George Washington University's space policy institute. "There seems to have emerged over the past couple of years a systematic problem in the space community of insufficient attention to detail."
The loss of the Mars probe was the latest in a series of major spaceflight failures this year that destroyed billions of dollars worth of research, military and communications satellites or left them spinning in useless orbits. Earlier this month, an independent national security review concluded that many of those failures stemmed from an overemphasis on cost cutting, mismanagement, and poor quality control at Lockheed Martin, which manufactured several of the malfunctioning rockets.
But NASA officials and Lockheed executives said it was too soon to apportion blame for the most recent mishap. Accident review panels convened by JPL and NASA are still investigating why no one detected the error.
"It was launched that way," said Noel Hinners, vice president for flight systems at Lockheed Martin's space systems group. "We were transmitting English units and they were expecting metric units. The normal thing is to use metric and to specify that."
None of JPL's rigorous quality control procedures caught the error in the nine months it took the spacecraft to make its 461-million-mile flight to Mars. Over the course of the journey, the miscalculations were enough to throw the spacecraft so far off track that it flew too deeply into the Martian atmosphere and was destroyed when it entered its initial orbit around Mars last week.
John Pike, space policy director at the Federation of American Scientists, said that it was embarrassing to lose a spacecraft to such a simple math error. "It is very difficult for me to imagine how such a fundamental, basic discrepancy could have remained in the system for so long," he said.
"I can't think of another example of this kind of large loss due to English-versus-metric confusion," Pike said. "It is going to be the cautionary tale until the end of time."
At the Jet Propulsion Lab, which owes its international reputation to the unerring accuracy it has displayed in guiding spacecraft across the shoals of space, officials did not flinch from acknowledging their role in the mistake.- Reynard ortiz
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