The US should be concentrating on saturation of near-Earth objects with robotic probes, prospecting for useful metals, including titanium and precious metals. Meanwhile, 3.3 km Tantalus will continue to tant- uh, never mind...
http://books.google.com/books?id=QpajMuyXG8AC&pg=PA519&lpg=PA519&dq=tantalus+1975+ya&source=bl&ots=RYSwSrwjUJ&sig=WDGM7DnYGdn8vvOrD1iWf99m8vc&hl=en&sa=X&ei=VBEeVKPsJsX3yQTzlIE4&ved=0CFMQ6AEwCA#v=onepage&q=tantalus%201975%20ya&f=false