The first stage segments are just about ready to go. They have a long trip ahead of them from first stage contractor ATK’s facilities in Promontory, Utah to the launch site at Kennedy Space Center in Florida.
Last week, using specialty transporters, ATK moved the Center Aft Segment to a holding facility where it will be housed in preparation for the cross-country trek via railcar. Some one described these transporters as looking like something out of the Transformers movie and I don’t think that’s too far off. They are impressive looking vehicles.
That big black line you see running diagonally down the side is called a Z-stripe. The Z-stripe is a 24-inch wide stripe painted on the first stage motor segments that wraps from the top of the motor to the bottom. The main purpose of the Z-stripe is to provide a way for the I-X team to determine the roll attitude and rate from footage recorded by cameras on the ground. That footage serves as a backup to on-board data gathered during the flight. The Z-stripe will also provide confirmation that the rocket rolled 90° shortly after lift-off from the pad like it is supposed to. Measurement from watching the Z-stripe could be very helpful in the case that the flight goes differently than expected.
We’re expecting to ship the motor segments next month. They are the last few pieces of hardware to ship, so once they make it down to KSC, we’ll be ready to start putting the rocket together.