Please use this web form for any questions, issues, or suggestions for Rocket Calculator.

4 comments on “Support
  1. Dave says:

    Stupid question, but on alt prediction, is coast time the delay time (in that it takes into account the motor burn time), or should motor burn be added to the calculated value to obtain optimal ejection delay time?

    • pstanley002 says:

      Not a stupid question. The coast time is the time between motor burn-out and apogee. This can be used to determine optimal ejection delay time since the the delay grain starts burning at motor burnout. So, if the calculated coast time was around 5 seconds, you wouldn’t want a delay much shorter or longer than 5. If the delay were say, 3 or 7, the rocket would still be traveling at a higher velocity when deployment occurred, than if the rocket was closer to apogee.

    • pstanley002 says:

      The last response I gave was based on end-burner type motors. Composite motors typically ignite the propellant and delay grain at the same time. The published delay times for motors like mid power aerotech are ‘supposed’ the be the time after motor burnout. The extra delay time needed during thrust is accounted for.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: