[ExI] virgin to use 747

[spike]

From: extropy-chat [mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Michael Butler
Sent: Friday, December 04, 2015 10:57 AM
To: ExI chat list <extropy-chat at lists.extropy.org>
Subject: Re: [ExI] virgin to use 747

 


On Dec 4, 2015 10:33 AM, "spike" <spike66 at att.net <mailto:spike66 at att.net> > wrote:

> 10 million for 200 kg to GEO or 400kg to LEO is a lower price than competing systems.

A little drizzle for your parade. The announcement mentions 200 kg to *sun* synchronous orbit. Ball-of-twine, near-polar orbit. 

 

 

Cool thanks I did miss that.  I thought the ratio looked a little funny.  In general to get to GEO, you need a different guidance system from one suitable for just reaching LEO.  A rocket that could get 400 kg to LEO probably would be insufficient for getting 200 kg to LEO.  

Another way to look at it is this: it might be able to get 200 kg to GEO but part of that payload needs to be inertial guidance and fuel.  It needs to be the kind of fuel which can sit idle for the six hour trip to apogee, then once it gets there, figure out where it is, orient the business end aft, restart the thruster, shut it off again when the right delta V is achieved.  Then it needs the inertial reference equipment on board and station-keeping thrusters and such.  So for GEO, it isn’t exactly clear what they are calling payload.

spike 

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