As it was explained to me, the altimeter is the _primary_ way he will deploy the chutes. He wants back up control for the chutes as well as some sort of contingency steering or chute release in the event the wind carries the rocket out of range. He has had one hang up on high power lines already so I suppose a cable release for the chute might be a good application.

Bottom line is that he is looking for a data control platform that will accommodate receiving ground originated control messages. Any ideas??

Message: 7 Date: Thu, 6 Mar 2008 17:36:30 -0600 From: Wayne N5WD n5wd@charter.net Subject: [amsat-bb] Re: OT?? Model Rocketry To: amsat-bb@amsat.org Message-ID: 200836173630.364012@HPPAV2 Content-Type: text/plain; charset="iso-8859-1"

On Wed, 5 Mar 2008 20:05:10 -0500, Ivan Galysh wrote: <snip>

>?Now for doing an uplink to deploy parachutes, maybe as a backup.
>?For safety reasons, he should use an altimeter....I would not rely 
> on a comm link to deploy a parachute. I
>?would do it as a back up in case the altimeter doesn't do its job.

<snip>

Not to mention that it would be darned near impossible to be able to ascertain when apogee occurs with even a medium sized rocket at one mile high - and I know that I wouldn't want to deploy my mains after my rocket has had a thousand or more feet of altitude loss from apogee - instant shred! ---------------------------------------------------------------------- R. Wayne Day N5WD n5wd@charter.net IRLP Node 3997 -> Lake Worth, Texas Fort Worth, Texas USA