[amsat-bb] Re: Falcon 9 video - moving early?

[B J]

--- On Sat, 6/5/10, Andrew Glasbrenner <glasbrenner at mindspring.com> wrote:

> From: Andrew Glasbrenner <glasbrenner at mindspring.com>
> Subject: [amsat-bb] Re: Falcon 9 video - moving early?
> To: vk1pe.peter at gmail.com, amsat-bb at amsat.org
> Received: Saturday, June 5, 2010, 4:57 PM
> SpaceX starts all nine engines and
> makes sure they are operating to spec before releasing the
> rocket from the pad. The shuttle does the same thing with
> the three shuttle engines before they light the solids. 

<snip>

That's been the case even earlier as well.  Listen to any of the countdowns for the Apollo lunar missions.  The Saturn V's engines would ignite at about T-9 and take a few seconds to produce full thrust before lift-off at T = 0.

If I'm not mistaken, in the very early days, T (or, as it was originally called X) = 0 was when actual ignition occurred, so lift-off was 2 or 3 seconds later.

73s

Bernhard VA6BMJ @ DO33FL