spaceflightnow.com
It all begins with 1.9 million pounds of thrust powering the Delta 4-Heavy rocket ever so slowly off the ground, taking more than 15 seconds for the vehicle to clear the launch pad tower on three pillars of flame from the hydrogen-fueled engines.
“It’s a spectacular ascent...It has a thrust-to-weight ratio of about 1.2-to-1 coming off the pad. So you get a lot time to watch it as it rises up above the umbilical tower,” Planeaux said.
The flames are visible, but there’s little visible exhaust, as opposed to SRB’s.
I anticipate hearing this one from the beach across the street tonight (Indialantic, FL about 20 some miles down the coast).
Compared to this launch, the STS jumps off the pad. Quite visible hope you saw it. MR of about 6 for the LH2/LO2 fueled RS-68 and then after-burning of the residual hydrogen with air. I felt the windows shaking in the facility I was in. We’re good through the first two burns of the DCSS RL-10 with one to go in the wee hours of the morning and then S/C sep.