摘要: A summary of these viewgraphs is: ROTVs (reusable orbit transfer vehicles)enable space tugs and space salvage. ROTV for space transportation has a lot to prove to PLS. Ground based better than space based ROTV. ROTV propulsion tec... 展开 A summary of these viewgraphs is: ROTVs (reusable orbit transfer vehicles)enable space tugs and space salvage. ROTV for space transportation has a lot to prove to PLS. Ground based better than space based ROTV. ROTV propulsion technologies to consider chemical rockets have limited mission capture, solar thermal rockets capture most missions but LH2 issues, and electric has highest PL without volume constraint. All technologies require more money to enable ROTV. 收起