*More on fuel economy, system management and life* Thanks CommSatMan. Mr A. wrote that attitude control fuel consumption was negligible, not that orbit control was negligible.
If Iridium needs to carry a heap of fuel to deorbit their satellites, that means that LEO satellites don't often go so far out of orbit that they crash into earth, otherwise, they could just be left to crash into the atmosphere when gravitational influences make their course wobbly enough. Therefore random orbits shouldn't be a problem for Globalstar provided they don't bump into other satellites, which instantaneous relicensing can handle.
Now, here we are back at battery life, which is where I came in. My original thesis was that photovoltaics, batteries and circuits needed to be in balance and the balancing mechanism is price per minute on an instantaneous basis.
Readware pontificated but never answered the question. His answer was 'don't worry your pretty little heads, we big satellite guys know what we are doing'. He should tell that to the Iridium shareholders. So far, the indications are that like so many other things, LEOs work a bit like a Simpsons episode - a conman promoter's monorail comes to mind. Shareholders in monorails need to check the foundations and gizzards.
You say fuel supply for orbit is trivial. Okay, but Mr A. and others who seem to know about these things disagree. Don't forget, we are talking about future random orbit constellations, not the existing one which is stuck with Satellite Jockeys keeping tight orbit. For this constellation, the batteries etc are already designed and up in space [half of them anyway].
All that can be done for the existing constellation is manage the minutes to maximize profit. Software can do that. The fuel supply and batteries can't be changed.
If battery management is crucial as you say, then let's check that out. The batteries need to be managed to minimize stress. Stress being, "...long periods of no or little load followed by short periods of extremely heavy loads. When this is coupled with the orbital aspects of eclipse, the charge and discharge cycle will not be uniform. This adds to battery stress and IMO will shorten life..."
We can smooth battery use by pricing the minutes higher at peak times and low at off-peak. It also means there is a marginal cost for a minute of use. Minutes are not 'free'. Every minute used damages the battery.
So far, Globalstar shows no sign at all of managing minutes by modulating price according to demand. Qualcomm is good at modulating photons. Maybe they could design some software to modulate $$ per minute.
With the present plan, we will have a slow increase in subscribers, high peaks and troughs in demand, flattened batteries with shortened battery and satellite life, busy signals to people wanting emergency help or needing to place an urgent stock market order or get an urgent quote to a customer, reduced revenue because minutes will be unused, frustrated customers, a weakened competitive position, waste of capital [both system and handsets which will be underused].
Other than that, things are looking good though.
I'm not surprised you don't believe the numbers of customers - we are making the system unattractive. Fortunately, Iridium is doing a much better job of making their system unattractive. But it does great flashes. ICO is going to show that they can put satellites in space too to add to the underused clutter and capital destruction on a grand scale.
Thanks again for the advice. Please give more!
Maurice
PS: Mr A said "...The flip side to satellite life is just plain old mechanical wear out. Much harder to predict, but that doesn't stop people from trying. The probability of a satellite failure due to mechanical wear out is gauged by its expected life due to fuel. For example, It would be dumb to have a satellite with a 99% chance of living to the ripe old age of 20 if it is only going to be launched with, say 2 years of propellant. So, the two design parameters are coordinated..."
So fuel does seem an issue. |
