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Re: Re: Heo, Leo, Meo



Hi Jon,

The challenge is finding the balance between size, weight, thrust, power and
not scaring the primary payload customer.

AO-40's arcjet needed 750w of power which was a challenge to provide even
with AO-40's relatively large solar panels.  A Delta II secondary payload
must squeeze in between the second stage and the payload fairing which
limits your size and as a result the amount of power you can expect from
solar panels.  It would take some creativity, but as I recall back in the
80's we were looking at a way to boost a satellite deployed from a Shuttle
Get Away Special can unto a usable orbit. Even with NASA's limits of being
non-flammable, non-pressurized and non-toxic we had to competing designs
being evaluated.

A good source (currently being updated) for flying as a Delta II secondary
payload is
http://centauri.larc.nasa.gov/uness/secondaryppg.pdf
drawings of the available space start at about page 50.

Lee-KU4OS


----- Original Message ----- 
From: "Jon Ogden" <na9d@speakeasy.net>
To: "Lee" <lee-fl@cfl.rr.com>
Cc: <amsat-bb@AMSAT.Org>
Sent: Sunday, June 22, 2003 1:32 AM
Subject: Re: [amsat-bb] Re: Heo, Leo, Meo


> Could something like the AO-40 arcjet be used to make some orbital
> changes?  It can't change inclination very much for sure, but it can
> certainly change apogee and perigee.  Or would it still not be enough?
>
> 73,
>
> Jon
> NA(D
>
> On Saturday, Jun 21, 2003, at 19:03 America/Chicago, Lee wrote:
>
> > I've thought about this too especially since the Delta II rockets used
> > for
> > GPS launches do sometimes carry secondary payloads.  The problem is
> > that we
> > would need some propulsion to get into a long term orbit.  So far I'm
> > not
> > aware of any secondary Delta II payloads that have had any propulsion
> > capable of a major orbit change.  All the secondaries I've seen are on
> > the
> > Delta second stage which after the second burn on a GPS mission would
> > leave
> > you in an orbit 101x622 nmi with an inclination of 37 degrees.  Even
> > the
> > third stage only gets the GPS satellite into a 101x10996 nmi transfer
> > orbit.
> > The GPS satellite then uses its own kick motor to circularize the final
> > orbit.
> >
> > One hope is that the DoD is developing a secondary payload adapter for
> > the
> > EELV (both Atlas V and Delta IV) program.  You can read about it at
> > http://www.te.plk.af.mil/stp/espa/espauser.pdf
> -------------------------------------
> Jon Ogden
> NA9D (ex: KE9NA)
>
> Citizen of the People's Democratic Republik of Illinois
>
> Life Member: ARRL, NRA
> Member:  AMSAT, DXCC
>
> Ham Radio Webpage: http://www.qsl.net/na9d   <- Updated on 1/12/03!!!
> Digital Photography Page:
> http://homepage.mac.com/jogden/Photography.html
>
> "It takes as much stress to be a success as it does to be a failure."
>
>                  - Emilio James Trujillo
>

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