The article about the APS study on boost-phase missile defense gave considerable information on the physical challenges of such defense. However, many more questions need to be asked and answered.
It may technically be possible to build a system to stop one missile, but how about 5, 10, or more? Where will those missiles be coming from? Who is going to have such missiles in quantity?
Can anyone guarantee that all incoming missiles will be stopped? What will such a total system cost? Are the potential lives and property saved worth that cost?
This and other space-based projects, many of which later turn out to be boondoggles, are supported by NASA, the military, and industries looking to generate job protection and company profits for years to come. The proposed manned trip to Mars, the permanent base on the Moon, the orbiting space lab now under construction, robots exploring the Mars surface, are or will be a waste of money. If water existed on Mars millions of years ago, what relevance has that to us on Earth today, or even in the distant future?
I think the excessive costs of space projects versus their minimal value gained needs a very careful reevaluation. I believe that very little has been gained from research in space; most of the benefits have been from research on the ground for the space program. Exceptions include satellites for weather, communication, Earth mapping, astronomy, and military information.
Congress will not stop spending on wasteful projects. The members get too much election campaign money from lobbyists. Citizens with some technical knowledge and common sense need to get together and demand a change in the funding of these projects, with members of the physics community taking a lead role. There are far better places than space to spend money for research, development, and education.
