Topics

1

Apollo 13 Moments of Interest / 003:56:32 TLI dynamics error shows Apollo 13 hurtling back to earth

« on: January 22, 2025, 08:54:39 am »

The DYNAMICS team Ray Reynolds and Bob Torres had a rough mission.

The Apollo 13 Mission Operations Report notes the following incident in the Problems & Resolutions section of FIDO's report:

The SIVB LOX dump and evasive maneuvers were input to the RTCC at (approximately) 3:46:00. At this time, the Selects requested that the 2:59:00 zero ΔV maneuver (used for CSM separation attitude definition) be moved back to TLI cutoff. Dynamics was so instructed, however, TLI was moved instead. This resulted in the ephemeris re-anchoring on the pre-TLI CYI vector. This situation was ultimately corrected by deleting TLI and re-anchoring on CCHU08. (The consequence of this was to "turn on" the RTCC pre-TLI vent model. With this vent on, and unknown, later impact point evaluations with MSFC would not compare. It was not until 24 hrs later that the "vent on" situation was noted as having invalidated impact point comparisons attempted prior to a GET of approximately 6 hrs.)

The re-anchoring of the ephemeris on the pre-TLI vector also had the side effect of impacting multiple displays used by the MOCR personnel, including the CLAD - the command module looking angle display - which was used by the INCO to configure the high-gain antenna and also identify which spacecraft omni provided the best comm. At ~3:56 after the dynamics error, the CLAD was now showing the spacecraft Apollo 13 hurtling back towards the earth, because all the ephemeris knew was that 13 was still in orbit.

COMM Ed Fendell has a field day with this, delighting in embarrassing the FIDO over it. In the FIDO loop, Dave Reed is noticeably annoyed at DYNAMICS. "Mark yourself down for one," he orders them. Whether this is part of a disciplinary action or to buy Dave a beer later is unclear.

Link (COMM&INCO): https://apolloinrealtime.org/13/?t=003:56:32&ch=53
Link (FIDO): https://apolloinrealtime.org/13/?t=003:57:26&ch=20

2

Apollo 13 Moments of Interest / -02:01:30 Slayton doesn't want Mattingly to self-quarantine

« on: January 21, 2025, 06:48:28 pm »

Those who might have listened to the pre-launch loops may have heard at some point an isolated "CAPCOM, Stony, come up super-loop, Joe." The subsequent transmission was apparently to notify Kerwin that there is an incoming phone call from Slayton. This timestamp concerns that call.

Deke Slayton, Director of Flight Crew Operations, calls CAPCOM Joe Kerwin on the telephone during the launch countdown sequence. They chat briefly; his main druther is he wants someone to make it crystal-clear to Ken Mattingly that he shouldn't feel afraid (and by extension, no one around him should feel afraid) to have him in the MOCR pre-launch. This is an interesting deviation from the party line that was held during the pre-launch press conference where there seemed to be a unanimous agreement that Mattingly shouldn't fly due to measles exposure. Based on Slayton's language here, it seems that he's not at all convinced that there is any need for him to quarantine himself.

Link: https://apolloinrealtime.org/13/?t=-02:01:30&ch=15

3

Apollo 13 Moments of Interest / 139:13:22 John Aaron proposes unthinkable power-saving solution

« on: December 16, 2024, 10:08:02 pm »

During the re-entry shift, EECOM John Aaron and EECOM Sy Liebergot make their case for never powering up the glycol pump (nominally it was to come up 1 hour prior to re-entry) in order to save power in the CSM. John cites 2TV-1, a test run where Apollo mission-critical equipment was tested under thermo-vacuum conditions to determine when it would actually fail, and makes the supposition that the spacecraft could still make a G&N re-entry safely even without glycol cooling.

Both Arnie Aldrich and Neil Hutchinson in SPAN explode with outrage at the idea. Although John's engineering analysis makes sense, especially since the command module is still freezing cold, it's unthinkable precisely because no CAPCOM would be willing to make the call to the crew to shut off cooling equipment required to preserve the spacecraft's sensitive electronics. They are especially concerned about the G&N and the components which rely on the glycol pump (PIPAs and IRIGs).

Thankfully, this was relatively far down on the list of the "emergency power-down" list and never ended up being needed.

Link: https://apolloinrealtime.org/13/?t=139:13:22&ch=16

4

Apollo 13 Moments of Interest / 116:55:33 The possible sim at 2 o'clock has been scrubbed

« on: November 01, 2024, 09:16:36 am »

A re-entry simulation that was due to be conducted at 2pm in the afternoon is officially stricken when AFD calls the SIM SUP, letting him know that Gene Kranz ordered for it to be canceled due to timeline considerations. This later thrills the FIDO on duty (Dave Reed), who was concerned about having to give up real-time tracking data due to the simulation requirements.

It is indeed rescheduled to 6am the following day, the same time that the White Team is going on shift - and a nail-biting eight hours prior to entry interface!

Link: https://apolloinrealtime.org/13/?t=116:55:33&ch=6

5

Apollo 13 Moments of Interest / -03:59:38 "Watch your six, STONEY." GO for crew departure

« on: November 01, 2024, 08:53:23 am »

STONEY Paul Weitz gives the go for crew departure to Skip Chauvin. Vance Brand then chimes in.

It's worth noting that both Weitz and Brand were Naval aviators, thus the friendly and jovial warning, "watch your six".

Note Apollo 13 preceded Top Gun by about 16 years, and the use of that phrase in the armed forces as a "keep your eyes out/watch your back" type warning has persisted for even longer!

Link: https://apolloinrealtime.org/13/?t=-03:59:38&ch=7

6

Apollo 13 Moments of Interest / -04:18:35 Vance Brand checks out the command module

« on: November 01, 2024, 08:34:29 am »

Per the PAO transcript, courtesy of the Apollo 13 Flight Journal:

(-04:19:58 GET) This is Apollo Saturn Launch Control; we're continuing in our hold at the T minus 3 hour and 30 minute mark. This is a planned hold at this time scheduled to last for 1 hour. The close-out crew has just recently arrived at the 320-foot level. They went across the swing arm to the White Room area and have now opened the hatch of the Command Module, which has been named Odyssey. The backup pilot, Vance Brand, has entered the spacecraft at this time. The close-out crew consists of 6 men. The pad leader, the backup pilot, a NASA quality control man, two spacecraft technicians, and [...] two suit technicians.

Some interesting things to note about the checkout procedure:

• It appears that as Vance goes through the tests, his callsign changes depending on where in the center couch he is seated. His first spoken lines over the loop identify himself as the "CDR" when he attempts to begin the chlorination procedure, until Skip redirects him. Later, he identifies as "BCMP" when he's inspecting the MC&W lights, given that he's the backup backup pilot (with the backup pilot, Swigert, of course having been placed into the prime crew).
• The STONEY or capsule communicator is nominally Paul Weitz, though at this point, he was apparently running late getting to the launch site. One of the Cape technicians named Joe Battaglia was going to sit in for Weitz until he arrived, but it doesn't appear that this happened. (Little is known about Joe other than that he was an engineer at the Merritt Island facilities.)

Link: https://apolloinrealtime.org/13/?t=-04:18:35&ch=7

7

Apollo 13 Moments of Interest / 029:21:52 GUIDO Fenner wants to look at the telescope

« on: October 25, 2024, 11:34:46 am »

Prior to MCC2, GUIDO Will Fenner asks RETRO Bobby Spencer how to get into the observatory to look at the telescope, presumably to watch the spacecraft or the S-IVB. Aside from walking directions, Bobby gives Will the "magic words" on how to get into the building, since he was apparently denied entry the last time he had attempted.

Link: https://apolloinrealtime.org/13/?t=029:21:52&ch=21

8

Apollo 13 Moments of Interest / 125:28:47 AFD needs Xerox copies of the entry checklist ASAP

« on: October 21, 2024, 10:52:37 am »

It is often overlooked just how rushed and slapdash the last few hours were prior to reading up the re-entry procedures for Apollo 13. The reason it took so long to read the procedures up to the crew was because someone (possibly Gerry Griffin or Neil Hutchinson) insisted on ensuring that all of the flight controllers could get copies of Mattingly's checklist to review simultaneously with the reading of procedures -- and the Xerox machine nearest to the MOCR was broken.

Link: https://apolloinrealtime.org/13/?t=125:28:47&ch=6

9

Apollo 13 Moments of Interest / 125:12:38 FIDO Stoval doesn't want to know his P-tube station number

« on: October 21, 2024, 10:28:52 am »

RETRO Bobby Spencer and RETRO SUPPORT Bob Davis (a backroom SSR person whose technical capability is comparable to John Aaron's) wants to send FIDO Bill Stoval some data to help him answer an inquiry he received from NORAD. There is a problem, however, and it's nothing to do with the data, but rather the ingenious method that NASA built into the MOCR to help mail documents from one room to another - the pneumatic tube (P-tube) system.

Each engineer's console is fitted with a P-tube station, which is assigned a simple one or two-digit number.

Bill Stoval, the FIDO who was on duty for three burns during Apollo 13 -- MCC2 in translunar coast, the PC+2 abort burn in circumlunar space, and MCC5 in transearth coast -- is currently working his most "lax" shift in the MOCR, with both crew and MOCR practically on standby while the entry procedures are being finished up. He is nonplussed when asked to give his station's number.

Link: https://apolloinrealtime.org/13/?t=125:12:35&ch=19

10

Apollo 13 Moments of Interest / 136:12:29 "We've got the BOOSTER consoles completely occupied."

« on: October 17, 2024, 09:11:50 am »

At roughly 6.5 hours prior to re-entry, Neil Hutchinson in SPAN calls up GNC Buck Willoughby and proudly proclaims that the CSM engineers have completely filled up the SSR rooms, including the consoles that would have presumably have been used by the Booster engineers (or in Neil's parlance, the "Booster dummies") to spectate on re-entry. Earlier in the night, he had warned the CSM backroom folks to get in early to beat them to the punch.

As a humorous note: At around the same time that Milt Windler warned about access being restricted to the MOCR and SSRs due to overcrowding concerns, EECOM Charlie Dumis had cleverly asked his backroom personnel what they planned to be doing during re-entry. Dick Brown (EPS) said that he would be working on the Olivetti punching up numbers - and all of his colleagues thereafter said they would be helping him on the Olivetti. These "jobs" helped to justify them being in the SSR, ensuring they'd be able to view the re-entry.

Link: https://apolloinrealtime.org/13/?t=136:12:29&ch=18

11

Apollo 13 Moments of Interest / 091:46:05 FIDO Boone tries (and fails) to micro-manage Chuck Dieterich

« on: October 01, 2024, 08:08:41 am »

Background:
Although the FIDO is nominally and de facto the "leader of the trench" (save, of course, for the Chief of the Flight Dynamics branch), there was most certainly still an unwritten hierarchy that existed within the trench's corps. Jay Greene and Dave Reed were widely (and rightfully) regarded as the most experienced and most skilled FIDOs who got assigned to most if not all of the powered flight duties (liftoff and lunar descent) since they would need to have the confidence and nerves to know whether or not to call an abort. Bill Stoval was the midcourse man, and he oversaw two of the midcourses during Apollo 13 - the SPS GNN midcourse to a hybrid trajectory, and the manual DPS burn midcourse for corridor control. Bill Boone was the other FIDO scheduled to work.

As of the time of Apollo 13, Boone had been in the Flight Dynamics SSR during Apollo 4 and had also been a FIDO in Apollo 7, Apollo 11, and Apollo 12. Glynn Lunney's shift after the accident was intended to have the crew asleep starting at around 60 hours. Instead, at 61:30, they executed the DPS midcourse to free return, and Boone provided the trajectory for this. The original burn would have put them in the middle of Madagascar, until RETRO Tom Weichel asked FIDO to move it off the land into the Indian Ocean.

He had been regarded as a "junior controller". From Ed Pavelka's oral history:

]"In this particular flight we were introducing several new flight controllers, and we actually had dual assignments on some of the shifts. I was with another controller, Bill [William J.] Boone [III], who was a junior controller. So I was on the console with him as his trainer, if you will, or on-the-job training type. Other positions had this, too. So for many of the shifts, Bill would be there, and I would come in with him for the difficult parts or what was more complicated. Actually, during the part of the accident where they discovered it, I was just coming on when the information began to come in."

While Pavelka went to do troubleshooting at the other consoles during Lunney's shift, Bill Stoval and Jerry Bostick provided support for Boone. Later after the PC+2 burn, Jay Greene would act as Boone's "supervisor" on the subsequent shifts, when he himself wasn't pulled away to attend planning meetings.

Description:
Boone is now working his back-to-back shift in the MOCR, having been on for the Maroon team (Milt Windler as FLIGHT) shift after the PC+2 burn and now filling in for Dave Reed during the Black team shift. Lunney has now posited to the Trench that in addition to making considerations in selecting a TIG time for the corridor control burn, they now need to factor in weather avoidance with a mild storm in the Mid-Pacific Line area.

FIDO Bill Boone calls up RETRO Chuck Dieterich to discuss weather avoidance. Whether it's due to fatigue, or perhaps overenthusiasm or trying to find something to do, Bill Boone initiates a bizarre exchange on the loops where he declares "we don't have any contraints [on when to do the weather avoidance burn] as long as it's between those two numbers [104 and 118 hours]." This immediately makes Chuck prickly. When Boone holds his ground and declares that he's simply trying to ensure they're both attacking the problem the same way, Chuck replies brusquely "I know what my job is, Bill."

Apparently Chuck was genuinely angry, since he snubs Boone later at 91:54:30. When they do finally get to talking again, Boone apologizes.

Link: https://apolloinrealtime.org/13/?t=091:46:05&ch=20

12

Apollo 13 Moments of Interest / 056:40:24 RETRO Spencer nixes direct abort

« on: September 05, 2024, 11:09:59 am »

Pretty self-explanatory. During the height of the crisis, RETRO Bobby Spencer has run the numbers on how much it would cost to do a direct abort at T+60 - 10,000 ΔV (delta V, or available velocity). The numbers he gives to Maroon FLIGHT Milt Windler are unrealistic. Milt doesn't realize this at first as he tells Bobby "work on that", but soon they quickly come to the conclusion that it's not doable. Even the subsequent conversation involving 7,000 ΔV implies that they would have the SPS engine for an undocked burn.

They will not.

Link: https://apolloinrealtime.org/13/?t=056:40:24&ch=19

13

Apollo 13 Moments of Interest / 133:06:41 Trench grumblings about Milt Windler & CSM checklist

« on: September 05, 2024, 09:00:53 am »

At 133:00:49 GET during a last-minute review of the CSM entry checklist, Maroon FLIGHT Milt Windler tells RETRO Tom Weichel that the P-27 updates for a state vector and target load should only be done if absolutely necessary due to shortness of time. Since the order came directly from FLIGHT, RETRO just "rogers" it. But later on, it's clear that some dialogue is happening off the loops regarding how problematic this thinking is. In particular, YAW Gran Paulis points out that the crew doesn't even need to do anything while the loads are being submitted. He surmises Milt Windler must have thought that some reading-up of PADs were necessary to the crew.

FIDO Jay Greene, rather boldly and concisely, suggests that Paulis assumed too much too quickly about Milt's thought process.

Link: https://apolloinrealtime.org/13/?t=133:06:41&ch=20

14

Apollo 13 Moments of Interest / 141:15:37 Jack Garman predicts LM jettison gimbal lock

« on: August 30, 2024, 03:39:29 pm »

During the LM jettison, in a brief conversation with YAW Will Pressley, Jack Garman warns him that "transience in separation" might cause a CSM gimbal lock to occur. He's referring specifically to oscillations in attitude as a result of the delta-V imparted on the CSM in separation. The deadband isn't as much of a concern since the spacecraft is in a 5-degree deadband; thus, the middle gimbal angle is moving between 10 and 20 degrees from gimbal lock.

Later, one of the AGC support personnel calls the gimbal lock warning, but because his voice on the loop is so faint, it's missed and it's a full 3 or 4 seconds before anyone from the ground brings this to the attention of FLIGHT/CAPCOM. By that point, it's already too late and Swigert has already gone to direct control to correct this, but Garman does take this as an opportunity to remind Pressley of his concerns.

Link:
Before gimbal lock - https://apolloinrealtime.org/13/?t=141:15:37&ch=22
Gimbal lock - https://apolloinrealtime.org/13/?t=141:30:14&ch=22

15

Apollo 13 Moments of Interest / 141:02:53 Reed: "I'm gonna jam him back in!" Panic over Lovell's wrong turn

« on: August 30, 2024, 03:11:05 pm »

In "13 More Things That Saved Apollo 13", it notes that Jim Lovell put the Apollo 13 spacecraft 90 degrees out of the desired jettison attitude (LM yaw, CSM/body roll), since LM yaw was an out-of-plane orientation and going to the PAD attitude would have put the spacecraft in gimbal lock. In looking at the air-to-ground and PAO loop, there is no indication that there's any issue with this, as CAPCOM Joe Kerwin reassures Lovell that the yaw isn't critical.

In the trench, it's a much different story.

After Swigert's fantastic P52 which bypassed the need for a sun-moon alignment, there was a frantic effort by both the ground and the crew to get the LM jettisoned. As a result, Kranz never got a formal "go" from GUIDO Ken Russell for the jettison attitude. In the chaos, the "go" came from CONTROL Hal Loden, which created a stir in the trench. GUIDO pointed this out to FIDO Dave Reed and warned him that CDR Jim Lovell was bailing out of the LM, per the air-to-ground. Reed made a remark that would have been unthinkable coming from any other FIDO: "I'm gonna jam him (Lovell) back in!"

What follows is a very confused series of events, and it really benefits to listen to the whole loop from 141:02 to 141:10, as it progresses from the trench bickering and arguing over the safety of the jettison attitude (the normally cool and professional Dave Reed audibly vacillates on whether the attitude is safe), with FAO and CONTROL jumping in to provide their input. In the end, the question is brought to FLIGHT, Gene Kranz, with the eventual determination that they have no choice but to accept the new jettison attitude. Either way, this is arguably the moment of greatest panic throughout the entry prep for the Trench.

FIDO: We need to have Jim take the LM to the FDAI angles that we gave him on the LM jettison pad!
FLIGHT: How far off is he?
RETRO: Flight--he's gonna jettison the service module to the north--I mean, the LM to the north. We don't want him to the north, we want him to the south.

One thing of note about this exchange is that Kerwin asks if the concern is about the impact on the landing point of the atomic fuel cask (as mentioned in the article), but RETRO Chuck Deiterich explains, as he does in the article, that they simply want to ensure that the LM and CSM don't collide in the jettison. This is supported by the fact that Dave Reed later checks the relative motion of both spacecrafts with the new attitude, and verifies that both will be okay.

Link:
FIDO - https://apolloinrealtime.org/13/?t=141:02:53&ch=20
GUIDO - https://apolloinrealtime.org/13/?t=141:02:53&ch=21
CONTROL - https://apolloinrealtime.org/13/?t=141:02:53&ch=57