> In fact, if we delay until the distant future, or even 50 years or so, such an effort probably will become impossible. This is because us humans will consume

> In fact, if we delay until the distant future, or even 50 years or so, such an effort probably will become impossible. This is because us humans will consume the Earth's non-renewable energy and mineral resources almost completely within the next 50-100 years, severely reducing our discretionary income for costly activities such as space travel. I wonder when that was written...