Big Launch Vehicles CP and CG Points measurements

The Rocketry Forum

Help Support The Rocketry Forum:

hakanoren

Acidalia Aerospace
Joined
Jul 4, 2021
Messages
6
Reaction score
1
Location
Turkey
Hello there! What methods do they use to measure the CG and CP points of rockets such as Falcon 9, Atlas, Electron?
 

Antares JS

Professional Amateur
Joined
Mar 5, 2020
Messages
1,417
Reaction score
1,866
Location
Eastern Shore, VA
When we prep the Antares for launch, we have to report the weight and location of every component added so the CG can be calculated, among other things.

I'm not sure how CP was calculated. Probably either a wind tunnel model or calculated with a method not too dissimilar from barrowman.

CP only matters for a minute or two though until the vehicle reaches the upper atmosphere. With active guidance, CP only needs to be known for the sake of knowing how much torque the gimbaling engines need to apply to cancel out any natural tendency to flip over resulting from the lack of fins.
 

hakanoren

Acidalia Aerospace
Joined
Jul 4, 2021
Messages
6
Reaction score
1
Location
Turkey
You mean they DON'T use a big crane and do a SWING TEST??? 🤣🤣🤣🤪
haha obviously not :p
When we prep the Antares for launch, we have to report the weight and location of every component added so the CG can be calculated, among other things.

I'm not sure how CP was calculated. Probably either a wind tunnel model or calculated with a method not too dissimilar from barrowman.

CP only matters for a minute or two though until the vehicle reaches the upper atmosphere. With active guidance, CP only needs to be known for the sake of knowing how much torque the gimbaling engines need to apply to cancel out any natural tendency to flip over resulting from the lack of fins.
thanks for answer, I'm really appreciated
 
Top