The article proposes using hydrogen to be carbon-free fuel-wise: > Environmental Issues. One reason for insisting on LH2/LOX rather than Kerosene/LOX, hypergo

The article proposes using hydrogen to be carbon-free fuel-wise: > Environmental Issues. One reason for insisting on LH2/LOX rather than Kerosene/LOX, hypergolics, or solids/hybrids is that it's clean. We could launch one every minute and contribute less to global warming, ozone layer depletion, and other varieties of atmospheric pollution than 747s crossing the Atlantic every day. Also, exhaust and/or fluffy white clouds resulting from the occasional really bad day aren't harmful to anybody who happens to be downwind.