Main Chute Sizing

 RECOVERY
 Basic Techniques
 Recovery Design
 Two Stage Design
 Recovery Harness
 Ejection Systems
 Ejection Charges
 Black Powder Use
 Electric Matches
 Chute Protection
 Main Chute Sizing
 Drogue Sizing
 TN & Cord Info.
 Attachments
 Deployment Bags
 Backwards Sliding
 Drop Table
 X-form Descent
 Baro Tester
 Calculators (IE)
 Calcs. (download)
 Tracking
 Dual Deploy

 ELSEWHERE
 Parachute Design


Search the site!
The formulas provided below will calculate an estimated parachute size that will result in a descent rate of about 15 feet per second. If the landing area is hard, such as packed earth or salt, a slower descent rate may be desired to prevent damage to the rocket.

Circular Parachute

size in inches = sqrt( rocket_weight_in_pounds * 0.454 ) * 39.6

Example of a 5 pound rocket:

sqrt( 5 * 0.454 ) * 39.6 = 59.7" (60" parachute)

X-Form Parachute

size in inches = sqrt( rocket_weight_in_pounds * 0.454 ) * 51.5

Example of a 5 pound rocket:

sqrt( 5 * 0.454 ) * 51.5 = 77.6" (78" parachute)

A smaller parachute will result in a faster descent. A larger one a slower descent. If the ground is soft, such as grass covered, you may want to use a smaller parachute for a faster descent. A faster descent will result in less drift. If the ground is hard, like frozen earth or salt, you may want a slower descent, and therefore a larger parachute.

Submitted by Dean Roth


Check out the rocketry talk!
Check out our advertiser: Check out the rocketry talk!

Copyright © 1996-2000, Rocketry Online, all rights reserved.