<font color="yellow">You know what they say…. Untoasted launched come from happy Delta IVs, happy Delta IVs come from California. </font><br /><br /><img src="/images/icons/laugh.gif" /><br /><br />The "toasted" Delta IV launched from Florida was a "Heavy", e.g., with 3 CBC boosters, whereas the recent launch from VAFB is a "Medium plus" with only a single CBC plus 2 SRMs. <br /><br />Both launch pads have enclosed ducts. The difference is that with 3 CBC, the hydrogen from "fuel-lead" start of RS-68 has nowhere to go but up, there would be a higher back-pressure inside the duct, so the "toasting" is a far more visible effect with the heavy.<br /><br />Also, it's far more windy at VAFB SLC 6 so the hydrogen get blown off more so than at the CCAFS. <div class="Discussion_UserSignature"> </div>