[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: A Few Questions



I am not familiar with their business model but they seem to be targeting
small payloads. With the advent of the Ariane 5 and a multi-small sat launch
platform I would guess that they believe it will be easier and more cost
effective to be injected into GTO, then make an orbital manuever to a lower
orbit.

Out of hand it may sound like a waste of energy but being a "for profit"
corporation I'm assuming that they have done the math and figured that there
was either some cost saving, more frequent launch opportunity, or both to
have made such a business decision.

I was only pointing out that reaching MEO doesn't necessarily require a LEO
launch and then a bunch of fuel. It could be just as easily reached by going
to GTO and braking down to a lower orbit.

Your point about about preferring an STS or Soyuz hand launch isn't quite
practical in the launch business since neither the Russians or NASA would be
too interested in taking a commercial (or amateur) bird, loaded with fuel
(the discussion about getting to MEO from LEO) along with them for a ride.

73, Jeff-N9AVG


----- Original Message -----
From: "Bruce Bostwick" <lihan161051@earthlink.net>
To: <amsat-bb@AMSAT.Org>
Sent: Thursday, March 28, 2002 4:50 PM
Subject: Re: [amsat-bb] A Few Questions


> How do they use aerobraking to raise the perigee?  You pretty much have
> to burn at apogee to do that.  I suppose you could aerobrake to lower
> apogee and turn a GTO into a LEO, but that's an enormous waste of energy
> unless someone else is going out to GEO and dropping you off on the way,
> a la AO-40/PAS-1R.  Also, once you lower the perigee enough to
> aerobrake, you're probably not going to be able to raise it again
> without having some sort of secondary propulsion system to give you
> apogee kicks once you get to the right apogee altitude.
>
> Personally, if I built a bird, I'd want to be well away from the GTO
> trajectory, because there's a lot of discarded junk -- spent upper
> stages, bits of thrust structure, SRB exhaust condensate, etc. -- on
> that road and even a paint flake hitting a LEO bird at GTO perigee
> velocity will kill it.  I'd feel much better with an actual LEO launch,
> whether it meant an STS or Soyuz ride and a hand launch or some other
> smaller booster ..


----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home