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Mercury, November/December 1999 Table of Contents

ACT I
Professor - 42-year-old female who tries to make the subject real for students. Winner of her college's teaching award.
Student - 18-year-old male who wants to "land a good salary." Bright yet skeptical of anything that does not seem practical.

[Scene opens. Autumn sunlight plays on the cluttered bookshelves in the science Professor's office. Outside the open door are sounds of an approaching conversation.]

Student: I still don't see how this will be important to me. We've spent a week on this stuff.
Professor: And you still neglect your units in your work. It's just that a number without a unit means nothing if you're talking about a physical quantity.
Student: Yeah, but the person you're doing the work for will know what you mean...
Professor: If they don't? What if they've asked you for the lengths of bolts in centimeters, but you calculate and then give them numbers of inches, without saying you used inches?
Student: Ahh, come on, Professor, you get us to use metric stuff-kilograms, meters, dey-cuh-leeters-but nobody I know uses this stuff.
[The conversation continues, fading as music rises. Scene fades to black.]

ACT II

Engineer 1 - 52-year-old male NASA engineer.
Engineer 2 - 26-year-old male working on his first NASA mission. Under the direct supervision of Engineer 1.

[Music fades. Scene opens with Engineer 2 in the doorway of Engineer 1's office.]

Engineer 2: Yeah, I guess you're right. It's just that these numbers seem a little off.
Engineer 1: Oh, they look pretty close. Those fellas know their stuff. Gotta trust the experts a little, kiddo.
Engineer 2: Okay, but we're sure we're talking newtons here, right? Not having the force units spelled out makes me a little nervous. Blame a professor I had when I was in college...
Engineer 1: Drop it, okay? I'd think you've got some work to take care of before Friday's performance review.

[The young engineer leaves as the music returns. Scene fades to black, and then the twinkle of stars comes into focus. On the left appears Mars's limb. From the right comes a spacecraft moving quickly. We see the spacecraft approaching the planet. Shortly after we see small pieces of material leaving the craft, and finally we see the spacecraft disintegrate into large pieces. Fade to black again. Music is cut.]

EPILOGUE

[The scene is of Engineer 2's office, his back to us as he sits at his computer. His head is slumped. We hear the Professor's voice.]

On the morning of 23 September 1999, NASA's Mars Climate Orbiter was supposed to enter an orbit around the planet. But it did not, and the spacecraft is now considered lost. NASA officials report the probable cause as miscommunication between the spacecraft team in Colorado and the mission navigation team in California: one of the teams used English units of measure (i.e., feet and pounds), and the other used metric units (i.e., meters and kilograms). Unfortunately, neither realized the problem, and it is likely the spacecraft plunged too closely to Mars and was destroyed. We are left with points to consider:

• In measurements of physical quantities, numbers without units mean nothing. And no units can also lead to costly mistakes.
• Despite being convenient "human" units, English units should be put aside in favor of metric units (and with normally ten fingers and ten toes, we should find metric "human" enough).
• Is NASA's current strategy of "Faster, Better, Cheaper" the best in all cases?

[Fade to black.]

James C. White II, Ph.D., Editor