<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Dec 10, 2010, at 9:28 PM, spike wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><blockquote type="cite">On Behalf Of Adrian Tymes<br></blockquote><blockquote type="cite">If it's just a matter of exhaust velocity, what about ejecting stuff at 100+ km/s?</blockquote><br>Sure, but where do you get all the energy?<br></div></blockquote><div><br></div><div>From americium. And 100 km's is bush league, an americium rocket could give you <span class="Apple-style-span" style="font-size: small; ">200,000 </span>km/s.</div><div><br></div><div> John K Clark</div><div><br></div></div><br></body></html>