Re: [amsat-bb] A Few Questions

["Matt Davis" <mattdavis21@xxxxxxxxxxx>]

Hi Jeff,

I understand your point but there are many uncertainties to the Aerobrake 
technology mentioned earlier.

One is it has not been tested.  There is no heritage and I think in terms of 
selling point there have a lot to prove.

The system takes approximately 60 days to deliver a LEO satellite into its 
orbit after deployment from the GTO vehicle.  Could be reduced if they work 
around a lower perigee but that is very dangerous as the transfer vehicle 
could re-enter the atmosphere.  The other major issue is radiation as the 
transfer vehicle and the LEO satellite will have to go through the Van Allen 
Radiation belt and spend a few days orbiting in that belt in the course of 
lowering itself to LEO.  Unlike the other MEO orbiting satellite the Total 
Ionising Dose here could be very high as the satellite is not passing 
through the radiaton belt but infact it stays in that belts for a few days.

In addition, the aerobraking mechanism deployed has a large profile area and 
it is extremely sensitive to solar activities.  This can change its transfer 
trajectory and it adds complexity to managing the transfer operations and 
any miscalculation with regards to the solar activity could be costly.

If the satellite manufacturers can leave with all these uncertainties than 
definitely the launch service to be offered will be well accepted otherwise 
......

If you are interested there is an article about this on the internet. Check 
out:

http://www.aria.cec.wustl.edu/SSC01/papers/11-8.pdf

73

Matt


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