Bill,
... we can't engineer for "unknown" future events.
The L-band issues under discussion are not unknown. The impacts and regulatory remedies for the Galileo community against Hams are uncertain, knot unknown.
It just bogs us down with worry that we might not make the right "guess."
No one is bogged down. The Eagle design team is weighing the issues associated with each possible choice of uplinks and downlinks to maximize the utility of Eagle to the largest community of users possible. The debates on amsat-bb do not slow down the design process, although occasionally they do provide interesting material for consideration.
... base decisions on the engineering facts as we know them today ... and let the future bring on whatever it has in store for us.
That would be an irresponsible thing for AMSAT leadership to allow, and the Eagle project team knows it. To launch a high orbit satellite takes resources that stretch the capability of the Ham community to the limit. We must maximize the probability of a successful mission.
If you can make arguments that L-Band won't work ...
We are getting way off track here. No one is saying L-band won't work, now or in the future. What we are saying is that there has been some evidence to suggest that we could loose access to the band if "a" or "b" or "c" happens. This creates a concern that needs to be factored into the evaluation of the alternatives for Eagle.
But lets take this Galileo "cloud" off the decision process.
I repeat that this would be an irresponsible decision. What needs to be done is to evaluate this and other threats, which are largely out of our control, and integrate the treats and their mitigation into our decision making process.
I don't think many future AMSAT communicators will fault you for not being able to predict the future.
Really? I assure you that if we make a conscious decision to ignore an important issue and we turned out to be wrong there would be a massive campaign of criticism.
I predict that there will be multiple L-band uplinks and an S-band downlink on Eagle; they just won't be primary links. Whatever the outcome, the decisions will be based on the best information available to the Eagle project team, including inputs from the international community. They will also be based on the need to attract new young Hams to satellites so our future is secure.
Some of the people debating the issues on amsat-bb impress me as possibly qualified to participate directly in AMSAT projects or in other responsible roles. We have openings and I encourage you to contact your AMSAT officers and introduce yourself if you would like to volunteer you time and talent to the advancement of Ham Radio.
Rick W2GPS AMSAT LM2232