Why was a Shuttle launch countdown three days long? The answer to this question has roots back to the ‘elders’.
Those of us that were part of the final years of the thirty-year operational life of the Space Transportation System inherited some truly thoughtful processes from those who came before us. Some processes were born as early as the Mercury program, nourished through the Gemini and Apollo days, and adapted to the Shuttle needs.
In architectural design, it’s called “form follows function.” Ditto for many of the ways we processed hardware and launched our friends into space.
Granted, some early concepts for a new adventure like this didn’t pan out. The good ones did, and they live on today in virtually all launch system designs. I was asked to design the launch team for the Constellation program in the 2005 timeframe. As part of that effort a small group was formed and we benchmarked numerous high-power teams looking for best practices (and worst!). It amazed us how closely other successful teams resembled ours. Why? Because it worked, and worked well. Period. Nuclear subs, unmanned rockets, ESA and Russian space programs, emergency response authorities, aircraft flight testing, and others, had teams very, very similar to ours. But I stray…
Three-day long launch countdowns? The basic reason was it was easier and more effective to control the myriad of tasks in those three days under one governing, integrated procedure than had they all been conducted as individual, stove-piped operations. Integrating all the tasks under one orchestra leader (the NASA Test Director) allowed for better command and control, and visibility for managers like me. The NTD would integrate and lead all the element Test Conductors, ensuring no conflicts, or overlaps, or omissions.
What tasks? In the simplest form they were these. On the first two days:
- Pad closeout and securing
- Fuel Cell cryogenic reactant loading
- Communication system activation
- Flight Crew equipment stowage
- Rotating Service Structure retraction to its launch position.
On day 3—Launch countdown day:
- External Tank fuel load
- Astronaut boarding
That’s basically it. Within these major tasks were hundreds of steps , but that was about it.
This basic design was created by my predecessors and not changed much at all for the 135 Shuttle flights. Norm Carlson, Apollo Launch Vehicle Test Conductor (the forerunner to the Shuttle NTD position) knew it would work. His compatriots knew it would work. We inherited it and it still worked.
Like many of the other processes we (the “late bloomers”) inherited, we enjoyed ones already tested and proven successful.
To Norm, Tharpe, Tribe, Horace, Page, Sieck, Fuller, Breakfield, and so many, many others—Thanks.