What is an "altimeter" used for in rocketry?

An altimeter is an essential instrument in rocketry designed specifically to measure the altitude of a rocket during flight. This device provides crucial data regarding how high the rocket ascends, which is important for both performance evaluation and mission planning.

Understanding the altitude can help rocket engineers and hobbyists assess the effectiveness of their designs, predict landing zones, and ensure that recovery systems are activated at the appropriate times to safely retrieve the rocket. Altimeters can also be used for analyzing the rocket's trajectory and providing feedback for future launches.

The other options focus on different aspects that do not align with the primary function of an altimeter in rocketry. For example, measuring the weight of the rocket, monitoring fuel levels, or recording launch time are important factors in rocketry but are not the function of an altimeter.