At 02:54 AM 9/22/2006, Bill Ress wrote:
Yes - those are admirable desires but we can't engineer for "unknown" future events. It just bogs us down with worry that we might not make the right "guess." Instead, as I stated before, base decisions on the engineering facts as we know them today (available technology, size, power, space, resources, user needs, etc.) and let the future bring on whatever it has in store for us.
If you can make arguments that L-Band won't work because of system engineering constraints or the mission objectives we have before us today - I can live with that. But lets take this Galileo "cloud" off the decision process.
Bill: I think one of the problems still is how to get a large enough L-band gain antenna on the satellite so that the ground station antennas don't end up being huge. If I got that wrong, perhaps Bob McGwier and the team could correct me. If we cannot get a high gain system with reasonable beam-width (steerable vs. non-steerable) on the satellite, then the ground station antenna might be unwieldy compared to the higher frequencies.
Again, I may have misunderstood this point, so I could easily stand corrected.
Dave