Apollo 17 documentary

I happened upon an excellent 104-minute documentary from 2015 I’d never heard of before, titled “The Apollo Experience: Apollo 17” and linked below. It’s among the best single-mission Apollo documentaries I’ve seen and I figured I should mention it here because it has to be pretty darned obscure for me to not know of it.

I have the complete lunar surface videos from the mission – the boxed set pictured at the end of this post – but this documentary puts EVA highlights in context with explanatory captions and follows the mission from training to splashdown. The archival footage throughout is of the highest quality I’ve seen and quite a treat on a fifty-inch television.

The overall quality is high enough that I forgive the engine noise the producers added to some radio transmissions, along with other low-key add-ons like electronic “beep-beep” effects. They did them in a fashion subtle enough that, while I knew immediately that they were their additions, I wasn’t compelled to say “Wut?” and put on my just-ate-a-lemon face.

Timeline’s YouTube channel is worth exploring as it has hundreds of other history documentaries. Some, like this one, come from obscure satellite channels, but it appears a large percentage of their content originally aired on Channel 4 in the UK.

Don’t get me started

The excerpt below is from the site of Apollo 17 Lunar Module Pilot and geologist Harrison “Jack” Schmitt, and it’s the most…well, invigorating description of a jump start I’ve ever read.

This goes hand-in-hand with my article on the explosive guillotine in the Lunar Module because Schmitt describes an emergency scenario that Apollo crews planned for and practiced in which the launch sequence has failed: The guillotine has not fired, the four explosive bolts holding the two stages together have not exploded, and the ascent engine has not started. This is one of several contingency methods mission planners worked out.

Bear in mind as you read Schmitt’s explanation that this would be happening after they had tossed their Portable Life Support System backpacks out onto the lunar surface to save weight during the ascent, and after they had closed up the LM and repressurized the cabin in preparation for departure from the lunar surface.

It’s not often I find something about Apollo I’ve never heard before, and this one is boggling. I bolded the last bit of the excerpt because that’s the point when the ramifications sank in and my eyebrows shot off.

Wednesday, November 8th [1972], brought on our last full Lunar Ascent Mission Simulation involving Mission Control in Houston. Six weeks hence, we hoped we would be undertaking the real thing and departing the Moon at the conclusion of a highly successful exploration effort. This “Sim” required over three straight hours in LMS2, including the debriefing with SIMSUP (Simulation Supervisor). Failure or degradation of the primary guidance or engine ignition subsystems constituted the primary concerns addressed in Ascent Simulations. We particularly worked through several scenarios involving failure of the various software-initiated means of igniting the Ascent Engine.

Schmitt in Lunar Module Simulator 2. NASA photo ap17-KSC-72PC-539

We did not have a great deal of concern about our Challenger Lunar Module, like all the others before it, having just one Ascent Engine, because, in fact, it was at least two engines that just looked like one. Only the solid metal fuel and oxidizer injector ring and the exhaust nozzle below that ring did not have identical, that is, “redundant” components that would function even if a primary component failed. No one could imagine a failure mode for these non-electronic and solid pieces of hardware.

If all internal Ascent Engine ignition options actually failed, and many such options existed to fall back on, we also had a set of jumper cables that could be used as a next to last backup to ignite the Ascent Engine. These were called the “ED/APS Emergency Jumper Cable” and would use power from an independent Pyrotechnic Battery in the Descent Stage to open the engine’s fuel and oxidizer valves and fire the pyrotechnic cable and bolt cutters that would simultaneously separate us from the Descent Stage.

To use the second of these cables, however, one of us would need to egress Challenger in order to access a regular Descent Stage battery. Integrity checks of our suit would determine which one of us would perform this emergency EVA. If Cernan’s pressure suit did not pass its pre-egress checks sufficiently to permit egress with the jumper cables, we would change positions in the cabin, a tough task on its own. As we would have already jettisoned our Portable Life Support Systems, it would be necessary to use the OPS (Oxygen Purge System) we had retained to support the EVA that Evans would perform to retrieve film canisters from America’s Scientific Equipment Bay after leaving lunar orbit for home. The 8000 psi oxygen bottle in the OPS could provide a maximum of 30 minutes of oxygen and air-cooling once activated. There would be no water cooling, however, without a PLSS.

With the Challenger’s cabin depressurized, the winner of the integrity check contest would take one end of the pair of cables out the hatch and down the ladder and move to QUAD III where a battery could be accessed. He would then tear away the Kevlar covers and attach the color-coded pair of cables to the positive and negative terminals of a battery and then return to the cabin. At the optimum liftoff time for ascent into a rendezvous sequence with Evans, Cernan would attach the cables to two circuit breakers near his left shoulder. This action would supply instant power to the two sets of hypergolic (ignite on contact) hydrazine and nitrous oxide valves in the Ascent Engine. Once power reached these valves, they would open and lock open. With opening of these valves, a signal would go to the cable and bolt cutters. We would be instantly on our way into lunar orbit, still in an un-pressurized cabin, dragging our jumper cables behind us. Once back in lunar orbit, we could clear and seal the hatch and pressurize the cabin.

The aim of this emergency EVA was to bypass relay boxes, internal wiring, and the Explosive Devices control panel in order to get power directly from a descent stage battery.

The descent stage explosive device battery, aka the pyro battery, in question was near the front, highlighted here. This procedure bypassed that in favor of a regular descent stage battery.

In later LMs, Apollo 17’s included, five descent stage batteries were at the back of the LM, shown below in an illustration from the Lunar Module LM 10 through LM 14 Vehicle Familiarization Manual [link to PDF]. Two of the five had low voltage taps; the jumper cable would be affixed to one of those.

I’m glad they never had to do this, but it actually sounds like it would work. You might think, “Yeah, except for all the cardiac arrests and such”, but you have to remember that these guys were cool customers. Witness the fact that they practiced for this instead of climbing out of the sim and seeking the nearest bar posthaste when told of the method.

Schmitt says this method was the “next to last backup”, which makes me wonder intensely what on Earth Moon the last backup was. Spit and baling wire?

Edited 24 August 2018 to add: The entire emergency EVA procedure is detailed in Apollo Operations Handbook/Lunar Module/LM 11 and Subsequent/Volume II Operational Procedures, available on the Apollo Lunar Surface Journal site. See section 5.4.25 Loss of ED Sub-system.


I think I found the answer to my “What’s the last backup?” question there: The other choice was to quickly get to the rover – in the case of Apollo 17, parked about 158 meters away for best liftoff camera coverage – start it up, drive it back to the LM, and hook up to one of its two batteries. Now that would really be a jump start for the ages, but I think far less preferable considering there was just 30 minutes of oxygen available in the OPS.

The moon is a messy place

In which I discuss moon suits, moon dust, moon models, and moon stories

“Smells like someone just fired a carbine in here.”
– Apollo 17 Commander Gene Cernan on smelling moon dust inside the Lunar Module

I finally got around to making my 1/6th scale Gene Cernan figure look a little more realistic. Brand new, it looked like this:

Apollo 17 Commander Capt. Gene Cernan, the last man on the moon, in 1/6th scale

I never quite liked the pristine look of it because the only time it was that clean was the day it arrived from the manufacturer, ILC Dover, a division of Playtex at the time the suits were designed. Yes, Playtex designed the 21-layer Apollo suits. Here’s the figure after I applied a fair amount of graphite powder using two different brush sizes:

Now you may think I went a little over the top with that, but I didn’t. My variation is probably about what Cernan’s A7LB suit looked like after two of the three seven-hour moonwalks he and Jack Schmitt made. Below you can see what his suit looked like after their third and final moonwalk on 13 & 14 December 1972 – and this was after they spent quite a while brushing each other off before re-entering the Lunar Module for the last time.

Click for a larger version

The large brush they used for the suits – and the lunar rover – was six or seven inches wide. They also had a smaller brush for camera lenses and such. You can see both in this compilation. Gene Cernan raises his gold-plated visor here while cleaning the rover’s camera lens.

Moondust is funny stuff – fine, powdery, almost like snow, and it smells of burnt gunpowder when it’s on the moon. That smell goes away on prolonged contact with normal air, so the returned samples no longer smell of anything. They don’t really know why it smells like gunpowder, but there are some theories.

Excerpts from the Apollo 17 Technical Crew Debriefing [corrected link to PDF] on 4 January 1973, during which the problems with dust came up a lot:

“Dust – I think probably one of the most aggravating, restricting facets of lunar surface exploration is the dust and its adherence to everything no matter what kind of material, whether it be skin, suit material, metal, no matter what it be and its restrictive friction-like action to everything it gets on. For instance, the simple large tolerance mechanical devices on the Rover began to show the effect of dust as the EVAs went on. By the middle or end of the third EVA, simple things like bag locks and the lock which held the pallet on the Rover began not only to malfunction but to not function at all. They effectively froze. We tried to dust them and bang the dust off and clean them, and there was just no way. The effect of dust on mirrors, cameras, and checklists is phenomenal. You have to live with it but you’re continually fighting the dust problem both outside and inside the spacecraft. Once you get inside the spacecraft, as much as you dust yourself, you start taking off the suits and you have dust on your hands and your face and you’re walking in it. You can be as careful in cleaning up as you want to, but it just sort of inhabits every nook and cranny in the spacecraft and every pore in your skin. Although I didn’t have any respiratory problems, I think the LMP, which he can comment on later, had some definite local respiratory problems right after the EVA – due to dust in the cabin.”
– Commander Gene Cernan

“Dust – We’ll just talk about in-cabin dust. After the first EVA, there was considerable dust in the cabin. It would be stirred up by movements of the suit and the gear that we had. Almost immediately upon removing my helmet, I started to pick up the symptoms that you might associate with hay fever symptoms. I never had runny eyes or runny nose. It was merely a stuffiness in the nose and maybe in the frontal sinuses that affected my speech and my respiration considerably. After about 2 hours within the cabin, those symptoms gradually disappeared. By morning of the next day they were gone completely. After the second and third EVAs, although I’m sure the dust was comparable, the symptoms were not nearly as strong as after the first EVA. That was as if I either developed a mucous protection of the affected areas or had some way or another very quickly developed an immunity to the effects of the dust.”
– Lunar Module Pilot Jack Schmitt

Here’s James Burke, prime Apollo reporter for the BBC, wearing – and removing, one by one – all the components of the A7L spacesuit. The A7L was used through Apollo 14 and the more advanced A7LB, with essentially doubled consumable capacities that allowed for seven-plus-hour moonwalks, was used on Apollo 15, 16, and 17.

That report was prepared prior to the moon landings. In 1979, Burke did an excellent ten-year anniversary documentary that explains a lot of the workings of lunar missions better than most.

I think this is a great time to start reading Spacesuit: Fashioning Apollo. I’ll do that tonight.

I also now have a lighted display case for the Dragon Lunar Approach model I have at home. In normal light, it looks like this:

In the dark with the case’s inbuilt lights turned on, this is closer to how the pair would appear in the sunlight of deep space during the translunar coast:

Finally, a treat: Several years ago on BBC Radio 4, Jeanette Winterson did a fascinating ten-part, 150-minute series about the moon from many perspectives. It’s called “The Inconstant Moon” and you can listen on her site here. Quite a pleasant way to spend a couple of hours.

Radio 4 used this graphic for the programme: