posted 09-02-2016 11:44 AM               

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Originally posted by Daniel on the Moon:
How many of you are under the impression that EVA "training" PLSSs and OPSs were flight configured units that were downgraded (Class 111) for EVA crew training?

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posted 09-10-2016 11:43 AM               

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Originally posted by jklier:
I'm curious if you ever worked with this robot

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posted 09-10-2016 12:14 PM               

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Originally posted by carmelo:
Dan you have wear Apollo spacesuit and suit and PLSS inside mock up of Apollo command module and lunar module?

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However, I donned my PGA before entering the LM (up to PGA "zip up") and doffed the PGA after LM ladder descent.

posted 11-03-2016 01:30 AM               

My responsibilities as Apollo PLSS/OPS KSC EVA Crew Training Mission Manager began with a memo from MSC Crew Systems Division stating that the remaining Apollo 11 and all future mission EVA crew training exercises would be conducted at KSC and all EMU training hardware (suits, PLSS/OPSs, and supporting hardware) would be shipped to KSC in time for a June 6, 1969 KSC training exercise.

PLSS/OPS crew training hardware had already been designed and fabricated and was being used at MSC for Apollo 11 and preliminary Apollo 12 EVA Training. The PLSS/OPS training hardware that we received from MSC to support KSC EVA training was, contrary to popular belief, totally functionally different than the flight PLSS/OPS whereas the training suits were flight configured and downgraded to training status. Let me repeat and this is very important, The PLSS/OPS training hardware was totally functionally different from PLSS/OPS flight configured hardware.

My experiences and the decisions I had to make (as Apollo PLSS/OPS KSC EVA Crew Training Mission Manager) as a result of maintaining and managing PLSS/OPS EMU training hardware that did not perform as expected will be the basis of most of my future cS posts. It is a story that was never documented and in the interest of preserving and documenting a very important aspect of the "Apollo Story" for future historians I feel it is my obligation to document my experiences and the decisions I had to make.

Before I became involved with the PLSS/OPS training units, my work at KSC was with the Flight PLSS/OPS hardware. Because of my intimate knowledge of the flight hardware and my extreme enthusiasm about my work (my dream job), my request to be assigned PLSS/OPS Crew Training Mission Manager was granted (one of the many highlights of my Apollo experience).

I realized that I now had to familiarize myself with a totally new system both from a functional and procedural standpoint and concurrently continue my responsibilities as a KSC HSD engineer. Knowing the frantic pace at which Apollo schedules were moving forward I anticipated that my upcoming new responsibilities were going to be very challenging.

As I previously mentioned, the training PLSS Cryopack and OPS were totally functionally different from the flight configured PLSS/OPS. The flight PLSS/OPS was designed and built to function on the moon, not on earth. All components were, of course, designed with that in mind. Many of you know that suit ventilation cooling and body cooling (using the Liquid Cooling Garment, LCG) were accomplished through the process of sublimation, a process that only works in the vacuum of space using the PLSS sublimator that allowed ice to change from its solid state to a gas skipping the liquid phase. All other components were also specifically designed and optimized to function on the moon.

The PLSS was a fully autonomous system when used for its intended purpose on the moon. The PLSS controlled suit pressure, provided up to eight (8) hours of breathable oxygen, removed exhaled carbon dioxide, removed particulates and odors, provided body and ventilation cooling, controlled humidity and provided voice and telemetry communications.

Not only was the PLSS non earth function issue a reason for designing an earth training PLSS/OPS but also the weight of the flight PLSS/OPS would have been an issue as the flight PLSS/OPS weighed 125lbs (PLSS - 84lbs, OPS - 41lbs). With the suit at 60 lbs, a total of 180 lbs would have been a serious issue for the crew magnified even more on the simulated lunar surface outside the crew training building in the heat of the spring, summer and fall Florida sun.

The weight issue was not completely resolved since the final weight of the Cryopack, OPS and suit was 130lbs (Cryopack - 60lbs, OPS - 10.5lbs, Suit - 60lbs). The weight difference of 49.5lbs however was offset by the lack of Cryopack LCG water cooling capability until the beginning of Apollo 16 crew training when I was given authority to fabricate a make shift cooling device that I and one of my crew training techs designed (details will be included in a future post).

Using the flight PLSS carbon dioxide and odor removal capability would have also been unfeasible as the PLSS Lithium Hydroxide Cartridge was a one time use component and it would have been cost prohibitive to provide new cartridges for every crew training exercise.

posted 11-03-2016 01:56 PM               

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Originally posted by MCroft04:
Were the flight PLSS/OPS tested in the vacuum chamber prior to launch? If so can you share who tested them and how it was done?

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Time constraints, especially a few weeks before launch, resulted in testing the flight and backup flight units, for most missions, beginning about three weeks before launch. The pre-flight tests were called "Pre-Installation Acceptance" (PIA) testing.

I'll take you through a brief summary of the testing as you requested using as an example Apollo 11 flight and backup PLSS testing. As LM-5 PLSS/OPS Mission Manager, I was very fortunate to have been the responsible HSD engineer for conducting the PLSS "Pre-Installation Acceptance" (PIA) testing for both Armstrong's and Aldrin's flight and backup PLSS/OPSs. The testing began on June 23, 1969 and was completed on July 10, 1969, just six days before Apollo 11 liftoff (July 16, 1969).

The procedures that all contractors had to follow with respect to conducting tests were as follows: First, a "Test Preparation Sheet" (TPS) was written to authorize the testing. Then, a "Test and Checkout Procedure" (TCP) was written to include the specific procedures used to conduct the test, i.e. how a specific components function was to be evaluated using the Clean Room Test Facility.

All of the PLSS system, sub-system, and component testing was performed using the above referenced HSD Test Facility and as we called it, the "PLSS/OPS Test Stand" (below photo). The Test Stand included a vacuum chamber that simulated the vacuum of space and provided the capability of testing the performance (function) requirements that the PLSS/OPS and its components were designed for.The PLSS and OPS were, of course, tested separately using separate Test and Checkout procedures (TCP).

As the contractor engineer in charge of the test, I read each line of each procedure to the HSD technician who turned the dials, pushed the switches, read the gauges, etc. After each test procedure, if the PLSS subsystem, component, etc. performed within test specifications, both the HSD Quality Control inspector and a NASA Quality Control inspector placed an approval stamp next to the procedure in the TCP.

If, during the execution of testing, there was an undiagnosed issue, an "Interim Discrepancy Report" (IDR) was written and logged in a "Test and Inspection Record" (TAIR) book without stopping the test.

Following the completion of the test, the IDR would be further investigated and dispositioned as either resolved or up-graded to a "Discrepancy Report" (DR).
A DR was written by the contractor (HSD) QC inspector for any out of specification test results. The DRs were entered into the TAIR book. DRs remained open until they were dispositioned and signed by the test engineer (me) and a NASA contractor engineer liaison that was permanently assigned to the contractor.

posted 11-03-2016 04:13 PM               

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Originally posted by Jeff:
Always interested in your first hand experiences.

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posted 11-03-2016 04:26 PM               

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Originally posted by jasonelam:
Thank you, Dan, for explaining the difference between a flight and training PLSS.

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posted 11-03-2016 04:34 PM               

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Originally posted by Kite:
What a responsibility you had. We are so much obliged to you on cS.

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posted 11-04-2016 11:27 PM               

The purpose of the procedure was to:

• Verify in flight EMU donning and checkout procedures.
  
• Provide the crew with a final look at the flight EMU hardware.
  
• Familiarize the crew with recent changes to flight hardware that might have been made.
  
• Provide an opportunity to resolve any open questions or items of crew interest.

posted 11-05-2016 11:04 PM               

As we all know, one of the normal signs of aging is memory loss. At 73, there are quite a few past events and parts about my life that I have difficulty recalling.

posted 11-06-2016 01:06 PM               

I'll gladly wait for the things you have to think about to remember... and I'm certain you will.

posted 11-07-2016 05:05 PM               

Cryopack functional orientation: The cryopack provides pressurization and ventilation to the astronaut during Lunar Surface EVA crew training exercises. Liquid Air is utilized to accomplish the required objectives. Liquid Air is air that has been cooled to less than -221.26℉ so that it condenses into a pale blue liquid. To protect the Liquid Air from reverting back to its gaseous state before it is functionally utilized (liquid air can absorb heat rapidly and revert back to its gaseous state), it is stored in a vacuum insulated container. In the case of the Cryopack, the insulated container is cylindrical as seen in the above photo.

The Cryopack operates as follows (refer to above photo): After the pack is filled (with Liquid Air), Vent Valve (V-1) is closed and Pressure Buildup Valve (V-2) is opened. This allows the liquid air to enter the Build Up Coil (A), vaporize and pressurize the Dewar to 140±3 psig at which time the Pressure Regulation Valve (B) closes and stops flow into the Build Up Coil (A). The Pressure Regulation Valve (B) then modulates between open and closed to maintain system pressure.

posted 11-07-2016 08:28 PM               

The photo has been corrected.

posted 11-13-2016 05:18 PM               

As I previously discussed and emphasized, the training PLSS Cryopack was totally functionally different from the flight configured PLSS. I covered differences between the flight PLSS and Cryopack Suit Ventilation, Suit Pressurization and Suit Cooling capabilities. Differences between the flight PLSS/OPS and training PLSS Cryopack Communications System have not yet been addressed.

To that end, I will, in this and one or two subsequent posts, discuss PLSS and Cryopack Communications System differences. First let's take a look at the flight PLSS Communications System referred to as the Extra Vehicular Communications System (EVCS). In Figure 1 above, I "attempted" to relate EVCS Block Diagram components to corresponding components in front and rear photos of the PLSS and the PLSS Remote Control Unit (RCU).

The EVCS, manufactured by RCA, accomplished three major communications objectives as follows:

• Provide primary and backup Dual Voice Transmission and Reception between earth and moon.
  
• Provide Telemetry Transmission of Physiological (Bio-Medical) data to earth.
  
• Provide Telemetry Transmission of PLSS Performance (Function) data to earth.

Nine telemetry channels transmitted to the LM carried PLSS and suit operational data. A tenth TM channel transmitted crewman electrocardiogram (ECG) data. Indicators mounted on the remote control unit (RCU photo in Figure 1) provided the astronaut with a visual warning of high oxygen usage rate, low suit pressure, low ventilation flow, low water pressure and high CO2 levels (Note the block diagram in Figure 1 does not include CO2 sensor monitoring as CO2 level monitoring was added later in the program) . When an abnormal (out of specification) condition existed, an audible tone sounded in the astronaut communications carrier (Snoopy headset). The audible tone alerted the crewmember to look down at his Remote Control Unit (RCU) to find the specific abnormal condition(s) defined by specific visual notification that appeared in RCU indicator windows, identifying the problem so that the astronaut was able to take corrective action.

Voice and telemetry communications was sent and received on three frequencies between the crewman and the LM. It is my understanding (correct me if I am wrong) that the astronauts communicated with each other via 279.0 MHZ. Voice communications from LM to the crew utilized 296.8 MHZ. Voice and data from the crew to the LM utilized 259.7 MHZ, however, voice and data from EVCS 2 (LMP) had to be transmitted to EVCS 1 (CDR) and then voice and TM from both crewman were transmitted to the LM through EVCS 1. Note that other optional communications modes were available (utilizing the RCU mode selector switch) if anomalies occurred.

Voice and TM data was transmitted from the LM to earth via the aforementioned S-Band antenna erected by the astronauts using frequency 2282.5 MHZ. Voice from earth to the S-Band antenna was relayed via 2101.8 MHZ. The below Figure 2 may help decipher my possibly incoherent explanation.

posted 11-14-2016 01:38 PM               

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Originally posted by LM-12:
What are the two PLSS-related fixtures seen in the LM near the tunnel in photo AS13-62-8935?

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Perhaps the following from the Apollo 15 final report (referring to vertical PLSS straps going up to the cabin fitting) is a clue!

If you're not careful with the vertical straps going up to the cabin fitting, you can put extra stress on that PLSS mounting; also, the interface of the straps could take off the thermal cover of the PLSS. IRWIN The straps on the Commander's side occasionally bear down on the Y-adapter and also the PLSS hard line. We should look a closer look at it. We should look strongly at some other way of securing the PLSS.

posted 11-14-2016 10:33 PM               

In my last post, I documented the operational functions of the flight PLSS Communications System (EVCS). As a reminder, the PLSS EVCS was utilized to provide voice communications and telemetry data for both astronaut bio-medical and PLSS operational data.

I also mentioned that the Cryopack EVCS hardware was identical to the PLSS EVCS! However, the capabilities of the EVCS were only partially utilized when used with the Cryopack for EVA training. Specifically, communications using the Cryopack EVCS was used for voice communications only. TM data transmission from the training PLSS Cryopack was not needed as there were no transducers in the Cryopack to monitor and send performance data and it was deemed not necessary to monitor astronaut ECG data. The thinking was that the close contact between crew members, techs and myself would allow us to visually recognize astronaut life threatening situations.

The training EVCS was mounted inside an OPS shell (Figure 3, #1) as there was no need for a working emergency oxygen system.

The above Figure 3 Cryopack communications Block Diagram shows EVCS connector "J4" connected to the PGA electrical umbilical connector in turn connected internally to the astronaut communications headset. EVCS "J5" connector is connected to the EVCS antenna mounted on top of the (OPS). EVCS "J1" connector was connected to a battery inside the Cryopack providing the EVCS with its power source. EVCS "J2" connector was connected to the PLSS RCU. Since there was no telemetry data, the only function of the RCU was to turn on EVCS voice communications by pushing the RCU "Push To Talk Switch" from "OFF" to its "MAIN" position and then rotating the RCU Mode Selector Switch from its off position "0" to its primary on position "AR".