Warms the cockles of me heart, it does. Beagle 2 was the tail end of the "we just can't get anything to land on Mars" period of space exploration - that deep hole that included the loss of the Mars Climate Orbiter and Mars Polar Lander, also known as the $110m check your math object lesson.
- The peer review preliminary findings indicate that one team used English units (e.g., inches, feet and pounds) while the other used metric units for a key spacecraft operation. This information was critical to the maneuvers required to place the spacecraft in the proper Mars orbit.
Yeah I remember that incident well. The following year I took my first college physics course, and the instructor used that as a model lesson in why paying attention to units is important. It's hard to leave anyone blameless in that case, but (admittedly not knowing any of the insider details) I can't figure out why the hell anyone wouldn't have used SI units on a project such as that. I've always assumed that the company who was using English must have been out of step with norms and protocols. But, like I said, it's pure speculation.
Sad that the program director of Beagle 2 died recently. I'm sure this would've made his career.
I'm almost positive that Lockheed is required to build in English units because 'murica. And while NASA tries to use SI, vast swaths of their infrastructure are English.
- The problem is that while Lockheed Martin’s space division operates entirely in metric, its manufacturing side and many of its contractors use Imperial Units because rebuilding sophisticated hardware in metric would be wildly expensive, says Edward Euler, the company’s program manager of the ill-fated Mars mission. For similar reasons, NASA requested proposals for its next generation of space shuttles in inches, feet, and pounds even while most of the agency’s own scientists use metric. “You really have two NASAs—one English and one metric,” says Euler, who adds that Lockheed Martin has the same problem. “We can’t buy our nuts and bolts to the metric standard—that’s the place, on the commercial and manufacturing side, where there’s really resistance.”
http://www.airspacemag.com/flight-today/commentary-metric-mayhem-1929361/?no-ist
This is the exact explanation.
I have submitted some mechanical prints with dimensions in mm to our machinists, and they looked at me like I was just crazy. They literally said "This is America!", like imperial units are the shit.
The engineering side of the American space industry works in imperial units exclusively. The science side of course follows SI convention. Honestly, I'm surprised that it's usually not too much of an issue, Mars Polar Lander and other notables aside.
Of course, with modern 3D CAD, all I need to do is click about 4 or 5 times, and I can get you the moments of inertia for an entire spacecraft spit out in any system of units you fancy, in any coordinate frame you fancy.
What's amazing is that the rest of the world, as far as machine tools goes, are still on Imperial.
Francesca is a bleedingly italian motorcycle. The guys I talk to to keep her running are either English or German. And you know what? They all use 1/4" or 1/2" drive wrenches. Sure, the actual sockets are something civilized like 10mm, but they aren't on a 12.7mm end wrench. Just today an Australian told a Briton to use a 24" 1/2" socket extension to fit a german part onto an Italian motorcycle.
- What's amazing is that the rest of the world, as far as machine tools goes, are still on Imperial.
Some quick research points to Britain's early dominance in the Industrial Revolution, combined with their metrication process not seeing official adoption until the mid 1960's. Apparently they still use imperial units quite a bit.
Anyway, it's almost time for a pint (WINKWINK) here in CDT.