"We have everything we need to do this," he said.
Good now we need to ask ourselves the question do we really want to do this? The accelerations on these sails are miniscule. Also the accelerations they do produce decrease the farther you go out from the sun.
It's interesting though to consider what it could mean in terms of travel from the earth to the moon. With no fuel the costs are nothing except what it costs to support the astronaut's life. If you could maintain a continuous 1 m/s2 acceleration using a 100m x 100m sail, you could lift about 1000 kg payload to the moon in about 40 days. So I guess it comes down to which costs more: fuel or food an oxygen? I'm thinking the shear cost of supporting an astronauts life for that time period would overcome any benefits you would get from using no fuel.
I would think that these sails are probably more useful on the same types of missions that Ion engines are used on. Those would be long flight duration probes that accelerate for years.
But it still doesn't tackle the greatest barrier to space exploration: the cost to get to low earth orbit. We need to get there before we get anywhere else.