if its clock hiccups again"
if I may add in ".... and fix the big problem we have of not understanding the fact that there may be gaps in TDRS coverage for launch and early orbit ops, at altitudes less than 750 miles.
Seriously, did the mission planning team not hire anyone (hire me!) to plan out comms coverage for commands/telemetry at low orbital altitudes (<750 miles) during Launch and Early Orbit phase?
Who decided to just trust automation on an untested spacecraft and booster on its maiden voyage?
Also, I am thinking that TDRS should have been expanded with more satellite coverage - but that is not an excuse for not knowing how to model safe modes (and contingency plans during safe modes) during loss of signal as TDRS coverage is already known in many forms.
TDRS can provide continuous global coverage of Earth-orbiting spacecraft above 750 miles to an altitude of about 3,100 miles. At lower altitudes there are brief periods when satellites over the Indian Ocean near the equator are out of view. This area is called the geometric zone of exclusion.
Related details - I don't have obviously any say in such matters, but why would the mission planners not have considered a comms contingency plan? Randomly, even an ORBCOMM like satellite data terminal integrated into the capsule/booster would have allowed them to stay in touch in absence of TDRS - this part is not rocket science, it's satellite communications and network engineering. But I am sure it would be a bit more difficult than that and have to be designed to compensate for relative velocity to the orbiting satcom network at MEO/LEO.
The two primary TDRS satellites are not located directly opposite each other with respect to the Earth. Instead, each is positioned such that it has a direct line of sight to the ground station located at White Sands, N.M. This positioning causes a gap where neither satellite has contact with the orbiter/ISS. The gap is located on the opposite side of the Earth from White Sands and is referred to as the Zone of Exclusion (ZOE). This is most likely the "missing chunk" you refer to. It's actually where the two "circles" (the flattened ovals) showing where there is no coverage overlap.
Data can still be obtained in the ZOE either by ground station at Diego Garcia if the orbiter or ISS is passing over it or via a third TDRS that must relay its data through an extra path to reach controllers on the ground.
BTW, while Boeing deserves to be criticized, I feel it is fair to point out that it's not uncommon to make mistakes in space program development, but one could argue, it's not common to make such silly mistakes, as - oh I don't know - perhaps have a discussion on how to deal with comms blackout
zones? Here is a Russian example of recent, the Phobos-Grunt mission that thought it reached Mars, but actually never left Earth orbit
Other errors on the mission included the system being designed so that the spacecraft was out of communications range after launch, so mission personnel had no idea how it was behaving. In this, the Russians repeated the error that doomed their Mars-96 mission.
What say you all?