Apollo 17: Farewell to the Moon

[CalliArcale]

In lieu of my "space history" thread for today, I'm going to start a thread for Apollo 17, the last of the Apollo lunar missions. I will update it every day with the activities of that day. Sort of like a mission update thread for a past mission. <img src="/images/icons/wink.gif" /> Apollo 17 was the last manned mission to the Moon.<br /><br />The crew were Commander Gene Cernan, Command Module Pilot Ron Evans, and Lunar Module Pilot Harrison "Jack" Schmitt (who was also the only professional scientist to ever set foot on the Moon). The mission was targetted at the Taurus-Littrow highlands in hopes of locating a wider age range of rocks than had been found on previous missions, including the Soviet Luna 16 and 20 missions. Indeed, on this mission the oldest lunar rocks of all would be found, although the press didn't seize on them as much as they did on the famed "Genesis Rock" of Apollo 15. Apollo 17 was configured as a J-series mission, which meant it was capable of a longer stay on the lunar surface, carried more scientific instruments, and was equipped with a Lunar Roving Vehicle. It was the third of the J-series missions.<br /><br />Planned for launch at night on December 6, a two hour, 40 minute delay pushed the launch into the very early morning of December 7, 1972. At 12:33AM, the Saturn V roared to life on Pad A at LC-39. After nearly twelve minutes of ascent, it put the CSM/LM/S-IVB complex into an Earth parking orbit of 91.2 by 92.5 nautical miles. The crew performed their onorbit checkout tasks and after the health of the vehicle was assured, the S-IVB upper stage began the translunar injection burn at 3:46AM. This placed the Apollo complex onto the "free return" trajectory, which, if their Service Module completely failed to burn its Main Propulsion System, would loop them around the lunar farside before returning them safely to Earth. After the burn, they succesfully maneuvered the CSM away from the S-IVB and pitched it around to point right bac <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[drwayne]

I have always found it interesting:<br /><br />(1) The amount of fuel left in the SIVB and the length of time it burned after seperation<br /><br />(2) The remote control of the SIVB - there were a couple of burns involved in sperating and aiming for the moon if I recall correctly.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[henryhallam]

The S-IVB didn't actually burn the remaining propellants after separation (only capable of one restart). Instead it vented them through a nozzle. But yes, the remote control aspects are pretty interesting.

 

[CalliArcale]

It was probably pretty boring during the translunar cruise. There was one activity on Flight Day Two: at MET 35:30:00, the MPS was burned for two seconds. This was the first of four planned midcourse correction burns, but it went so well that no further burns were performed until LOI (Lunar Orbit Insertion) two days later.<br /><br />I'm afraid I won't have anything to post for Flight Day Three; the sources I've found don't show any details for that day. So we'll pick this up again on Saturday. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[viper101]

"tedious translunar cruise"<br /><br />Ha ha ha - I'd give my right arm to endure that journey!<br /><br />Why was the SIVB only capable of one restart?

 

[darkenfast]

I've read that the J-2S engine has three pyrotechnic cartidges for starts. Was this true of the J-2? Does anyone know if an S-IVB was ever started again after CSM/LM seperation? <br />Thanks, Calli for this series! Great way to mark the mission anniversary.

 

[henryhallam]

What about actual ignition of the LH2/LOX? Was that spark-based?

 

[CalliArcale]

It occurs to me that I'm not really doing flight days, but calendar days, so I'm switching the title of these posts to "Day x".<br /><br />At some point during the translunar coast, perhaps on Flight Day Three, the crew performed a series of experiments including a heat flow and convection demonstration, and a light-flash demonstration.<br /><br />At 10:17 AM EST, December 10, the scientific instrument module door on the service module was jettisoned. This exposed the scientific instruments for orbital study of the Moon, including a high resolution camera. Later that day, at 2:47 PM, the MPS was burned for lunar orbit insertion, placing the combined Apollo spacecraft into a selenocentric orbit of 170nm x 52.6nm. Four and a half hours later, the MPS fired again to lower the orbit to 59nm x 15nm. This is the orbit they would maintain until undocking on Day Five.<br /><br />And that's when the mission will start to get really interesting. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[CalliArcale]

Sorry for the delay in posting this; i was having difficulty getting online at all today.<br /><br />Day Five saw the next really major event in the mission: descent to the lunar surface. Commander Gene Cernan and Lunar Module Pilot (and field geologist) Harrison "Jack" Schmitt transferred into the LM "Challenger". Command Module Pilot Ron Evans remained behind in CSM "America". The crew then performed what would be reported as the smoothest LM checkout in the entire Apollo program. The hatches were sealed and then, a little after noon EST, the two spacecraft undocked. They separated normally at the beginning of their twelfth revolution around the Moon. Then the LM fired its engine to circularize its orbit, setting itself up for a more relaxed descent. A few minutes later, after verifying that all was ready, it inserted itself into the descent trajectory. Forty minutes later, they began their powered descent followed by a successful lunar landing at 2:55PM EST Cernan and Schmitt were now the thirteenth and fourteenth men to land on the Moon -- and to this day, still the last. Gene Cernan remarked "Epic moment of my life." He stayed pretty calm while piloting the LM; his peak heart rate was recorded as 97 beats per minute. (Neil Armstrong, by comparison, hit 150 bpm during his lunar landing. Then again, he had a nasty boulder field to avoid, and a lot more reason to worry.)<br /><br />Four hours after landing, the crew commenced their first EVA. It would last until shortly after midnight. During this EVA, they unstowed and deployed the third and final LRV of the Apollo program, deployed their ALSEP (Apollo Luar Surface Experiment Package), and then took the LRV for a spin. They drove a total of 3.5 kilometers, obtained 18 samples weighing about 31 pounds. The primary geologic objectives concerned the dark terrain near the LM, believed to be cooled lunar mantle. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[CalliArcale]

At MET 137:55 (about dinnertime, back in the US), Cernan and Schmitt egressed "Challenger" again for their second EVA. This was a more flexible EVA, and the timeline was modified on the fly as the astronauts spotted things of geologic interest. This was the EVA that found orange soil on the Moon, a quite startling thing to see after the gray monotone of the rest of the lunar surface. Its significance is still discussed today. They took five surface samples, a double-core sample, set three explosives for seismology studies, performed seven traverse gravimeter measurements, and collected a total of 75 pounds of samples. The EVA lasted for 7 hours 37 minutes and took them a record-breaking 7,370 meters from the spacecraft, wrapping it up and returning to the LM just after midnight. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>