Post #19421

(((NO REPLY))): Tina Peters ------*---*---*---*---*---*---*---*---*---*---*---*---*---*---*---* PLEASE DO NOT REPLY TO THIS EMAIL If you reply to this email, your reply will NOT be read. *---*---*---*---*---*---*---*---*---*---*---*---*---*---*---*---*---* Hi Folks, Juan here, Imagine the calm… breath it in… the light breeze. The subtle fragrances of grass, flowers, morning dew and… you breathing it in. In the distance, the occasional birds winging across the sky and the first rays of light as the morning sun provides its golden hour of optical clarity and polarized splendor. A large digital clock glows in the distance counting down minutes and seconds in anticipation of the spectacle ahead. The now, very nearly imminent, launch of one of the space shuttles. I’ve had the pleasure. So much goes into any space launch it's almost unfathomable. Tens of thousands of people are planning, designing and testing the payload; preparing every tiny component of the launch vehicle. If any one of the tens of thousands of parts fails it could delay, cancel or destroy a mission. No weak links can or should be allowed anywhere. The crew and backup crew training and retraining primary and secondary scenarios of ‘what if’s’; no single or multi-point failures allowed. Millions of ‘man hours’ of peoples lives condensed down to long seconds and mere minutes. As the clock display moves into single digit minutes, the assembled crowd becomes more focused, and the assemblage of people begin to shuffle back to their assigned seats. An occasional horn will be heard blasting final warnings as announcers proclaim last minute details. Those tiny commotions pale instantly as visible sparks begin gushing near the base of the rocket at “T -10" seconds. Those sparks are technically identified as ‘Radial Outward Firing Igniters’ (ROFI’s). Lots of disinformation has been spread by the ill informed media and armchair rocket scientists concerning those pyrotechnics otherwise also known as ‘sparkler’s. Their purpose is to light any traces of hydrogen gas that may have leaked and invisibly pooled at the base of the rocket in the final moments before main ignition which (experience has proven) can pose a problem. The sparklers definitely will get your attention but they do not light the hydrogen propellant coming out of the engines, that is done internally in each of the three main engines as they start in sequence, about 120 milliseconds apart, just as the liquid hydrogen propellant starts flowing simultaneously at exactly “T -6” seconds from launch! At that instant a lot still must happen before the release of the vehicle and its actual liftoff. Enormously strong bolts hold the body of the rocket in four strategic places on the sides of the solid rocket boosters (SRB’s) located at each side of the main hydrogen fuel tank which the shuttle is attached to on its belly. Amazingly, all that sizzling energy is firmly held in place while computers analyze and cross analyze the start and performance of each of the engines as they come to life. The nano seconds turn to milliseconds as the myriad network of sensors and computers throw data at each other at the speed of light; simultaneously, human controllers confirm that all three engines have started and every other mission critical system confirmed to be operating correctly. During these long moments, if anything anomalous occurs, there is a long moment (in a world of nanoseconds) when the launch sequence can still be stopped and aborted, but most of the ‘decision tree’ of information and reactions will have been gamed out and pre-programmed into computer systems long ago; the likelihood of stopping the launch at this moment while still possible, is extremely unlikely. This is especially true because of all the checks and checkpoints which occur long before the moment of the first main engine ignition.