[amsat-bb] Re: Discovery

John Magliacane kd2bd at yahoo.com
Mon Dec 11 07:58:09 PST 2006

Bob, N4HY wrote:

> The simplest kind of approximation says they are attempting to enter a 
> certain orbit which has a certain well known orbital period.  In order 
> to achieve this,  the motors would have to be going long past the time 
> the shuttle would come above the horizon here. We know from experience 
> how long the motors burn.

An interesting observation made by several of us who were able to view the 
Shuttle from the NJ/NY region was that the Shuttle's main engines were still
plainly visible AFTER the Shuttle had confirmed MECO.

Since I was listening to shuttle audio via our local ATV repeater, and the
NASA-TV feed into the repeater is via an MPEG-2 satellite feed (the
encode/decode process of which introduces some noticeable delay), I would have
expected to see MECO occur BEFORE the delayed announcement was received.  In
fact, just the opposite occurred.

Perhaps what we casual observers on the ground might define as main engine
cutoff (the extinction of visible flame) isn't the true STS/NASA definition.

I also observed the engines "sputter" for a while after MECO was announced.
In past launches, I attributed that effect to the Shuttle possibly moving
behind some clouds.

But the skies on Saturday night were absolutely pristine.


73, de John, KD2BD

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