Range and Direction Aqcuisition

I teach Engineering Technology to 7th graders and one of my units includes a pop bottle rocket project. I am looking for a "human error proof" way to measure the height of the rocket’s flight. I have used the altimeters sold by Estes but want something more accurate. So my question is, how can we really, truely, accurately measure the height of the rocket’s flight? Thanks for any suggestions or directions to other resources!
- Laurie (age 44)
Kulshan Middle School, Bellingham,WA USA

We don’t know if there’s any human-error proof way to do anything. One way to reduce the likelihood of error is to have several students measure the altitude from different angles. The average of their results should correct for small errors due to mis-estimating the horizontal distances. You can also help reduce human error by having the students write down their answers before they share them. That way, if the answers are seriously in disagreement, you know something’s wrong. If they don’t write the answers down first, they may all adjust them to agree with the most popular student, who may well be wrong. NASA reminds us of the possibility of this sort of error every day.
One very accurate way of measuring distances is to bounce radio waves off of the object as it is in flight. If you have both a radio emitter and detector then by measuring time it takes between sending and receiving a signal you can determine the distance. Of course people can screw that up too.

-James and Mike

(published on 10/22/2007)