Questions tagged [unit-systems]

Questions that involve the choice of a system of units for measurement or calculations. For example, metric, U.S. customary, or Imperial units.

Filter by
Sorted by
Tagged with
41
votes
3answers
14k views

Why did NASA use U.S customary units?

NASA was using U.S customary units (inches, feet, nautical miles, pounds, tons, US gallons etc.) during the Mercury and Apollo programmes, and beyond. There are significant disadvantages to using U.S ...
36
votes
4answers
6k views

Why wasn't the Mars Climate Orbiter's fatal error caught prior to launch?

The Mars Climate Orbiter failed in 1999 due to: ground-based computer software which produced output in non-SI units of pound (force)-seconds (lbf·s) instead of the SI units of newton-seconds (N·s) ...
13
votes
1answer
6k views

Did NASA use metric units for the Mercury missions?

Did NASA use metric or English units for Project Mercury? For example, did they measure delta-v in meters/second or in feet/second?
27
votes
1answer
4k views

ISS nuts and bolts; Metric, SAE or both?

The International Space Station (ISS) is a joint construction of many countries around the world. Most of whom use the metric system for measuring including sizing of bolts, nuts and fasteners. ...
4
votes
1answer
375 views

Martian Names for the Year and Month Time Units

A Martian day unit is called a Sol. A week is supposedly still 7 days/sols. Have there been any (real or fictional) suggestions for new names for other time units like the Martian year? How about ...