[amsat-bb] Re: Amsat conference follow-up regarding Cubesats, Education and Experimental projects and ITU

Joe Fitzgerald jfitzgerald at alum.wpi.edu
Mon Oct 12 19:08:09 PDT 2009


I enjoyed your presentation and comments during the symposium,  I
apologize that I did not have a chance to talk one on one. I'll take a
stab at some of your questions

> But first a few questions:
> Does cubesat employ all open standards, free for use, free of any
> copyright -or- patents ?

 The answer to this is substantially yes, although especially with patents
it is hard to ever know for sure.

> What are the lifetime design goals of a cubesat system, and if they
> deorbit in a finite time, can more than a few cubesats be deployed in
> various stages in the same orbital plane and orbital track ?

Even if many cubesats were deployed at the same time they would tend to
spread out more or less randomly throughout the orbit due to minor
variations in separation velocity over the course of a few weeks.

> BTW, I am curious, is there a certain orbital plane allocation for
> cubesats/altitude ? Who regulates this ? Could a cubesat (small) be
> launched into (e.g.) a fractional degree orbit .. e.g., 45.5 degrees
> and separate from 45.7 degrees etc as they are very small, or are the
> cubesats limited to separation in orbit by whole integer degrees
> inclination ?

The inclination of the orbit that a cubesat ends up in depends on what the
orbit of the primary spacecraft.  A so called "plane change" to a
different inclination is a very expensive maneuver in terms of propellant
... for example when the Space Shuttle goes to ISS it must launch within 5
minutes of the optimum time or the earth will carry the launch platform
out of the plane of the ISS' orbit and there won't have enough maneuvering
propellant to reach it.  There is no specific need to hit an integer value
of degrees, and to my knowledge there is no national or international body
to regulate such things.

-Joe KM1P

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