What is a good descent rate for parachutes to be calculated to?
Ft/sec or MPH, either or. Also recommendations for a rocket that weighs about 18 oz empty and between 20 and 25 loaded. Any help would be appreciated.
Descent rates are calculated usually in FPS, feet per second. 20 feet per second is considered pretty fast, while 10 fps is barely going. 15 is what a lot of people shoot for. Infocentral has a lot of good information. Their drop table, the height at which you drop it and the corresponding FPS is here .
Major factors effect your desired descent rate.
The ground where you launch, is it soft or hard (if hard you may want a bit slower descent)
Your recovery area, if small you may want a bit faster descent.
Your rocket, is it built like a tank or does it have fragile details that may break on landing.
You have to take all these factors into account when sizing your recovery device.