Okay!! I've gone back over my reference materials, including some 'Flight' magazines and old 'Aviation & Space Technology' clippings. <br /><br />And: I'VE SEEN THE SSME ROCKET LIGHT...<br /><br />SSMEs, re-usable or no are MAN-RATED. RS-68s are NOT: would cost mucho dollaros to make them so.<br />It seems that when SSMEs were tested to destruction in the days before the new BLOCK 2 improved SSMEs, a thrust rating of 114% percent was attained with *reasonable* reliability. It seems to me that with a cheaper, disposable version of the SSME (however thats done), the less-stressed BLOCK 2 with all its improvements (throat diameter, improved turbopumps with silicon nitride bearings, less welds etc.) would better be able to stand up to uprated thrust. A sea-level thrust of 420klb should then be obtainable.<br /><br />TOTAL SEA-LEVEL TAKEOFF THRUST OF SDHLV WITH 5-SEGMENT RSRBs & UPRATED SSMEs: 8.46 million pounds.<br /><br />Okay, I'm a disposable SSME convert. Count me in!!!<br /><br />Next step: Develop a really good Upper/Earth Departure stage. Some years ago I communicated with various interested people over the remaining F-1 and J-2 engines and was informed there were approximately 13x unflown J-2 engines left in existence. However, using 4x RL-60s would give adequate Earth Departure Stage performance for a 30+plus ton payload. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!! LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>