Bone Collector:
Mr. English Inch took the Orbiter on a ride, at a rate of $0.30487 per mile for $125 million dollars over 9 1/2 months and killed the orbiter in cold blood after a long 410 million mile ride. NASA RED PLANET dispatchers puzzled. NASA thought that Mr. METER was the cabby.
L O S A N G E L E S, Sept. 30 - A $125 million
spacecraft on a mission to Mars likely vanished last week because a contractor provided data in English measurements and NASA navigators assumed they were metric units, the space agency said Thursday.
The embarrassingly simple mistake and the failure to
notice it led the Mars Climate Orbiter to fly too close to
the Red Planet, probably causing it to break apart or burn
up in the atmosphere that it was sent to study. It disappeared early Sept. 23.
An Error in Error-Checking NASA officials said the data somehow escaped what is supposed to be a rigorous error-checking process. A report is expected in mid-November-in time to fix any similar problems with another spacecraft that is set to land on Mars Dec. 3.
The Climate Orbiter had successfully flown 416 million
miles over 9« months before vanishing just as it was
starting to circle the Red Planet.
"It does not make us feel good that this happened,"said Tom Gavin of NASA's Jet Propulsion Laboratory.
"This mix-up has caused us to look at our entire end-to-end process. We will get to the bottom of this."
In its preliminary report released Thursday, JPL said the spacecraft's builder, Lockheed Martin Astronautics,
submitted acceleration data in English units of pounds of
force instead of the metric unit called newtons. At JPL,
the numbers were entered into a computer that assumed
metric measurements.
Mostly Metric "In our previous Mars missions, we have always used metric," Gavin said.
"We should have had them in metric units," said Noel Hinners, vice president of flight systems for Lockheed
Martin Astronautics in Denver.
The bad numbers had been used ever since the spacecraft's launch last December, but the effect was so small that it went unnoticed. The difference added up over the months as the spacecraft journeyed toward Mars.
Mission navigators crunched the numbers to help understand the position of the spacecraft during flight. The calculations measured the force of small thruster firings that helped counteract the effects of the solar wind -energy particles streaming from the sun - and other natural forces.
The loss is not expected to affect NASA's relationship with Lockheed, which has built several probes for the space agency, including the Magellan probe to Venus and the Mars Global Surveyor orbiter.
Reviewing What Went Wrong "This country has not gone 100 percent metric," said Chris Jones, program manager for JPL's Mars Surveyor Program. "[Companies] continue to use the English system of units, and that's something we have dealt with effectively on other programs."
The investigations by Lockheed, NASA and outside experts will focus on the mechanisms that should have caught the discrepancy in numbers, said Edward Weiler,
NASA's associate administrator for space science.
"The problem here was not the error, it was the failure of the checks and balances in our processes to detect the error," he said. "That's why we lost the spacecraft."
Lockheed officials also are reviewing contracts to see whether the space agency specified the units of measurement, Hinners said.
Same Problem in Companion?
The orbiter's sibling spacecraft, Mars Polar Lander, is set
to arrive Dec. 3. Gavin said investigators are trying to
determine whether NASA made the same mistake with that spacecraft. It also was built by Lockheed Martin Astronautics.
The Mars Climate Orbiter was on a mission to study the Red Planet's weather and look for signs of water-information key to understanding whether life ever
existed or can exist there. It carried cameras along with
equipment for measuring temperature, dust, water vapor and clouds.
The Mars Polar Lander will study Mars' climate history and weather with the goal of finding what
happened to water on the planet. It is equipped with a
robotic arm that will collect samples for testing inside the
spacecraft. |
