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dwightlooi
Guest
The current favorite for putting Americans into space following the demise of the space shuttle spears to be a booster based on stacking a hydrogen upper stage on top of the Shuttle’s massive Solid Rocket Booster (SRB). There is no shortage of critics as well as proponents of this arrangement. But, <b>let’s assume that it works for a minute. If it works, is safe and does lift 22 tons to LEO with a 100 ton class upper stage – as ATK Thiokol is promoting it as being capable of doing – doesn’t it make the EELVs redundant?</b><br /><br />I mean really! Let’s take a step back and consider this. <b>Why fly a Delta IV Heavy with three hydrogen fueled boosters and three RS-68 engines to put 26 tons into low earth orbit? Why fly an Atlas V with a highly stressed, staged combustion, Russian made kerosene engine to put 12 tons into orbit? Why even fly a single Delta IV medium with the RS-68 engine its cryogenic isogrid fuel tank to lift 8 tons? Why bother?</b> Solids are simpler, cheaper and make a lot of lift off thrust. Why not simply have SRB derived rockets do all the work? A simple system such as follows can theoretically meet all our main stream space launch needs:-<br /><br />(1) <b>Baseline LV</b> -- a single 4 segment SRB topped with a 5m, 100 ton, upper stage with a J2 engine for 22 tons of payload to LEO.<br /><br />(2) <b>Growth LV</b> – a single 5 segment SRB with the advanced RLX expander cycle engine and a 150 ton upper stage for a 30 ton LEO capacity (which eclipses even the Delta IV heavy and is a simple 2 stage rocket with just one inherently simple expander type liquid motor).<br /><br />(3) <b>Light LV</b> – versions of the baseline vehicle with only two or three SRB segments, and a 50 ton upper stage to handle the 8 to 12 ton payloads common to commercial launches and currently served by the Arianne V and EELVs. When the growth version of the baseline vehicle enters service, the upper stage engine can be standardized to a derated RLX providing some increase in pay