An AGU Council statement (NASAc Earth and space sciences at risk, available at httpc// www.agu.org/sci_soc/policy/positions/ earthspace_risk.shtml) and an Eos editorial <Barron, 2005>, addressing NASA's envisioned manned Moon-Mars initiative, implicitly assume a zero-sum situation between manned and unmanned space programs. They also imply that the NASA initiative will not contribute significantly to science but will impact on the current and future health of Earth and space science research. I wish to respond to these concerns. It is generally agreed that the International Space Station and shuttle program have limited value and need to be terminated. But one should not assume that funds freed up by elimination of manned programs will accrue to unmanned programs. On the contrary, without a manned component, NASA will probably cease to exist. Congress likely will not continue to fund unmanned planetary exploration over the long term, and Earth and space researchers will then have to compete for support with scientists using non-space techniques.