Friday, December 07, 2012

Apollo+40: Godspeed the Crew of Apollo 17 - The Launch

Thousands assembled on December 6, 1972 on Florida's space coast for the launch of Apollo 17. It was sure to be an incredible show as the launch would take place at night due to the launch window required to meet the mission's date with the Taurus-Littrow region of the Moon.

Among the VIPs seated in the bleachers near the Vehicle Assembly Building at Kennedy Space Center was Charlie Smith, thought at the time to be the oldest living American and a staggering 130 years old (since debunked). Smith was a doubter, and was quoted as saying about the Saturn V sitting on Pad 39A, bathed in spotlights:
I see that's a rocket, but th' ain't nobody goin' t' no moon. Me, you, or anybody else.
But, go they would, one of the men for the second time, like the eight flights and twenty-two men before them.

Commander (CDR) Gene Cernan, Command Module Pilot (CMP) Ron Evans, and Lunar Module Pilot (LMP) Jack Schmitt boarded their spacecraft, Command/Service Module 112 (CSM-112) named America, atop their Saturn V in the early evening hours

Apollo 17's countdown progressed normally until the T-30 second mark. At this point, the terminal launch sequencer initiated a hold in the countdown because it could not verify that the S-IVB third stage had been properly pressurized for flight. Earlier in the countdown, the stage pressurization failed to execute automatically and the manual override wasn't processed correctly by the sequencer. This required a recycle to T-22 minutes in the countdown.

It took NASA's engineers about an hour to recycle the systems to the countdown restart point and to verify both that the previous glitch wouldn't reoccur and the workarounds put in place to get past the issues wouldn't cause further problems. The countdown resumed at T-22 at 11:00PM.

The countdown held again at T-8 minutes for final checks and reconfigurations to compensate for the delayed launch. This hold lasted until 12:25AM, December 7, 1972. The final eight minutes of the countdown progressed without any additional errors.

At 12:33AM, the countdown clock reached zero, and the last Saturn V to leave Earth for its intended destination with three intrepid explorers turned night into dawn:

This video has some pre-launch footage and natural audio from the filming point; several seconds elapse before the sound of the mighty Saturn V reaches the filmer:

Cernan, Evans, and Schmitt were on their way! (Following events in Ground Elapsed Time, or GET)

0:02:43 - when Apollo 17 left the pad, the combined vehicle weighed approximately 6,200,000 pounds, most of which was the S-IC first stage's propellent. In the first 2:30 of flight, Apollo 17's five massive F-1 rocket engines consumed over 4.7 million pounds of RP-1 kerosene and liquid oxygen. Its job done, the S-IC stage dropped away and the five J-2 engines of the S-II second stage took over.

0:03:19 - the Launch Escape System, no longer needed should the crew need to abort, was jettisoned. It took the Boost Protective Cover over the command module America with it, so that the crew could now see out their windows.

0:09:21 - the S-II second stage finishes its run, and the single-engine S-IVB third stage continues pushing Apollo 17 towards a proper Earth orbit from which they can depart our home for the Moon.

0:11:53 - Orbit! Apollo 17 makes it to Earth orbit with no errors. The crew now has a hectic three hours to prepare and insure that all their systems are go for the Moon.

At 2:53:15 GET, 3:26AM EST, Apollo 17 was given permission to truly leave home.
CAPCOM: Roger. Guys, I've got the word you wanted to hear; you are GO for TLI - you're GO for the Moon. 
CDR: Ok, Robert, I understand. America and Challenger with their S-IVB are GO for TLI.
TLI - Trans-Lunar Injection would relight the S-IVB engine to propel Apollo 17 past escape velocity and on its way. The burn started at 3:12:37 GET and lasted six minutes.

After TLI, the crew's work was far from done. CMP Evans took control of America and flew a short distance away from the now spent S-IVB stage, turned around, and returned to dock with the Lunar Module (LM) Challenger. Transposition and Docking, as the procedure was known, was completed by 3:57:11 GET.

The combined America and Challenger thrusted away from the S-IVB at 4:45:02 GET/5:18AM EST and began their long coast to the Moon. The S-IVB stage itself was then aimed for an intentional impact on the Moon's surface as a seismic experiment.

Outbound on the first day of the mission, the first non-aviator to fly in space, Jack Schmitt, looked back at the Earth with a scientist's eyes. He rattled off his observations of Earth's weather patterns and other phenomena like no space voyager had before. He also took a famous picture from about 28,000 miles altitutde, soon after America and Challenger began flying on their own, known today as "The Blue Marble":

Apollo 17 was just beginning the sixth and final of Man's greatest adventures.

No comments:

Post a Comment


Note: Only a member of this blog may post a comment.