Do you all remember the infamous crash of the Mars Climate Orbiter? It was one of two NASA missions to the Red Planet that crashed in 1999 as they reached the end of their long journeys from Earth. Mars Polar Lander made a hole in the rusty dirt in in December – after an on board sensor designed to extinguish the rocket motor once it landed mistook the jolt of the landing gear deploying as a safe touchdown – and shut off the engine while MPL was still 1200 feet above the surface.
MCO was supposed to orbit the Red Planet – but instead entered the atmosphere way too low and burned up in September . The navigation error occurred because the NASA team at the Jet Propulsion Lab in La Canada, CA was using the metric system (newtons) to measure the force created by a thruster – while the Lockheed Martin team in Denver was using imperial units (pound force). One pound force equals approximately 4.45 newtons, and the thruster firings were nothing more than mouse farts, so the discrepency was not obvious just by looking at the numbers. Unfortunately, the two teams never cross-checked their navigantion data. The rest is history – and the ignominous end to then NASA Administrator Dan Goldin’s “Faster, Better, Cheaper” approach to space exploration.
Which brings me to the posting below on NASAWatch.com. NASA is under a mandate to go metric because of the MCO mishap. But the agency is resisting the change for some reason. The irony is it was the JPL/NASA team using the metric system in the first place. LockMart was using pounds.
These days there is a lot of talk about the US remaining competitive in a global economy – and switching to the metric system is something that we should have done a long time ago. Jimmy Carter tried in the 70s…but he apparently didn’t have the newtons to move the masses.
“Following the loss of the Mars Climate Observer, the NASA Office of Inspector General initiated a review of the Agency’s use of the metric system. By law and policy, the metric system is the preferred system of measurement within NASA. However, our review found that use of the metric system is inconsistent across the Agency. A waiver system, which was required by law and put into effect to track metric usage and encourage conversion, is no longer in use. In addition, NASA employees are given little guidance on the Agency’s policy and procedures regarding use of the metric system.”
via NASA Finds The Metric System Too Hard To Implement for Constellation | NASA Watch.
Tags: Daniel Goldin, Earth, Jet Propulsion Laboratory, Jimmy Carter, Lockheed Martin, Mars, NASA, Red Planet, Space, Technology
Miles O'Brien 
May 30, 2009 at 1:53 pm |
It’s better than changing your name to ‘millimeter’; you clever fellow.
May 30, 2009 at 2:25 pm |
I don’t know. Any engineer who can’t multiply by 1.6, or divide by 39, or whatever…
May 30, 2009 at 5:00 pm |
This is hilarious! If scientists and engineers won’t budge, guess I’ll never be asked to change over. Phew!
May 30, 2009 at 9:09 pm |
Pretty soon you might have to change your name to KiloMiles.
May 31, 2009 at 12:38 pm |
Dear Mr. 1.609344 Kilometers O’Brien,
Making NASA use metric internally has had and will have no effect on US industry using metric. So that mandate will always require conversions somewhere that add risk, and that require constant diligence (and therefore money) to mitigate that risk. NASA is a teeny-tiny, itsy bitsy lever arm on industry, so what was the intent of the mandate?
If the Congress wants to make laws about using metric, then they need to bite the bullet and do it across the board. Of course, that will cost a lot of money to the largest industrial base in the world, so it will happen, um, never.
June 8, 2009 at 1:11 am |
As a spacecraft engineer (and educator) – I can clearly see the entrenchment of inches and pounds over millimeters and kilograms in the aerospace industry. It’s sad really, because until the Reagan administration the whole country had been heading over to the metric system. By the mid-1980s (after the government no longer funded or encouraged the conversion) automotive and medical equipment industries had already made across – whereas the aerospace industry had not.
As an engineer I strongly prefer the metric system, and if no preference is stated, that is what I use. But this doesn’t happen in aerospace except for micro electronics, where the vendors went metric decades ago.
Even with government support, converting the aerospace industry over to the metric system is a tough nut to crack. A medical device or new car model takes several years to develop – and that’s about how long it took for those American industries to switch. On the other hand, designing the next generation of airliner or launch system or one of the larger spacecraft missions can stretch out 10 to 15 years. And frankly nobody in aerospace wants to change measurement systems part way through a 12-year development program (and if you ever saw the stack of paperwork needed to build and qualify a spacecraft design, you’d see why).
The loss of the Mars orbiter is just a noticeable example of a situation where industry as a whole is half-converted, with half of our products designed using one system and half using the other – bouncing perpetually back and forth as we conduct business with each other like speaking two languages at the same time without ever making a mistake.
And I’m actually amazed the we don’t hear even more stories about mission disasters due to conversion errors, now that we’re ever more integrated with the rest of the world.
Ken Ramsley
June 8, 2009 at 10:14 am |
These mistakes are so easy to make!
June 8, 2009 at 1:21 pm |
BTW, there are still a number of US roads that have km distances posted, and I think a few near the Canadian border with speed limits posted in km/h ..
(and England still mixes mph with km/h, at least if you watch a lot of _Top Gear_.. I’m sure a sizable population there still considers the metric system a French mind control mechanism.. :p)