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Author
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Topic: Mercury-Redstone 4: Splashdown procedures
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robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 11-28-2012 10:54 AM
  
Without wishing to ignite the whole did he didn't he blow the hatch debate, could I get some things cleared up about the Mercury Redstone 4 mission?Was hitting the hatch opener with the hand the only way of opening the hatch from the inside? There was no backup device like a lanyard or anything like that, that could have gotten caught around the hatch opening device? Just to clear this up, hitting the hatch was the only way from inside to open the hatch? Also, did Grissom report a 6 inch rip in his spacesuit during the spacecraft's descent to the sea? Finally, why did he jettison the reserve parachute after splashdown? Was this part of the normal landing procedure or did he do it for some specific reason? |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 11-28-2012 01:59 PM
A NASA engineer, whose name escapes me for the moment though I think his name began with a 'B', came up with two scenarios which would cause the hatch to blow with no input from the astronaut.I don't think that these were ever detailed. |
ColinBurgess
Member Posts: 2043
From: Sydney, Australia
Registered: Sep 2003
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posted 11-28-2012 02:45 PM
The parachutes were primarily jettisoned for safety reasons. If the main chute was still attached to the craft there was the possibility that the helicopter rotor wash could force air underneath it, causing the flimsy chute to rise up unexpectedly, endangering the low-flying helo crew and even the astronaut. There was also the question of craft stability and staying upright in the water without the chute acting as a large type of sea anchor. It was a simple procedure for the astronaut to hit a switch after splshdown and the chute was gone. |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 11-29-2012 12:28 PM
The reserve chute was was normally jettisoned after landing to take some weight off the top of the spacecraft. This was done on MR-3. Grissom's suit did not have a six inch rip in it, but the parachute canopy did. Some have speculated that it was caused on opening by the outside plate covering the external handle coming free. |
robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 12-07-2012 09:46 AM
So to confirm, the rip that Grissom spoke about during the descent was in the chute and the reserve chute was jettisoned after splashdown to reduce the weight to the top of the spacecraft.Further points to clear up, did Grissom have a flotation device? I can see him holding onto something in the water that gets blown away by the downdraft of the helicopter. Also where was the oxygen valve that, leaked in water, located on his spacesuit? Was it on the upper left of his suit? Finally was his helmet recovered from the water? |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 12-07-2012 05:13 PM
No, Grissom did not have a flotation device. Personal life preservers and the floation collar came about as a result of the MR-4 flight.I think what he was grabbing for was the dye marker canister (but I also am not sure). The valve he left open was at the waist on the left side. Yes, his helmet was recovered later on that day. The sailor who fished it out of the water said it was floating right next to a 10 foot shark. |
robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 12-09-2012 05:15 PM
Correction, Grissom didn't hold onto anything in the water but as the wheels of the helicopter touched the water as it tried to recover the spacecraft something appears in the water near to him. It's hard to tell if it comes out of the spacecraft or is dropped from the helicopter, either way it's soon blown away.I think it's possible to also see Grissom's space helmet float away which begs the question did he take it off before the hatch blew and it popped out of the open hatch as the spacecraft sank or did he take it off and throw it out before he climbed out himself? |
taneal1
Member Posts: 237
From: Orlando, FL
Registered: Feb 2004
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posted 01-06-2013 10:18 PM
quote:
Originally posted by robsouth:
...something appears in the water near to him.
I believe you are referring to the brownish tube-shaped object that pops up from the sunken neck of Liberty Bell 7 as it first submerges. It can later be seen blowing around the waves due to the rotor down-wash. If so, that is the reserve parachute ejector bag. It is normally stowed below the chute at the bottom of the parachute canister. After splashdown, when the Recovery Aids switch is thrown by the astronaut, this bag is inflated and pushes the reserve parachute out of the spacecraft and onto the water. This aids the spacecraft in righting itself after splashdown, as well as increasing stability on the water by removing that heavy mass from the top of the spacecraft. In addition it facilitates astronaut egress through the top hatch, if necessary. The final step in this exit process is to vertically push the parachute container out of the top of the spacecraft to clear the "tunnel." The lighter the canister, the less effort required. If Grissom spotted it and could grab it, he may have been able to use it as an improvised flotation device. It's difficult to say whether it could hold enough air to keep him afloat, but I suspect he was ready to try anything! |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 01-07-2013 02:24 PM
quote:
Originally posted by robsouth:
....which begs the question did he take it off before the hatch blew and it popped out of the open hatch as the spacecraft sank or did he take it off and throw it out before he climbed out himself?
He removed it after splashdown when the hatch blew. It was due to be removed as part of the checklist, which Gus reviewed mentally prior, but when the hatch blew he "...reacted instinctively. [He] lifted the helmet from [his] head and dropped it, reached for the right side of the instrument panel and pulled [himself] through the hatch...". See this thread and page 55 of "Results of the Second U.S. Manned Sub-Orbital Spaceflight." |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 01-10-2013 06:53 PM
Some years later he recalled to a reporter's question, "I tossed the helmet down at my feet." This always led me to believe he was still inside the spacecraft. |
robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 02-06-2013 12:40 PM
Finished reading, "Grissom: The Lost Astronaut," and I noted several things of interest. Firstly, he must have kept his helmet on to enable him to communicate with the recovery team so he couldn't have hit the plunger by accident with it. This means that if he did hit the plunger then it must have been with another object because there were no marks on his body.Secondly, that Robert Thompson stated that once the safety devices had been removed, the plunger could just slide in and yet I was under the impression that it required a force of five pounds to activate it. Thirdly, that tests had been carried out afterwards by Sam Beddingfield that proved that a malfunction could blow the hatch by accident. Under what conditions could this occur? I have heard that extensive tests afterwards could not get the hatch to blow by accident which is why I had always believed that he must have accidentally hit the plunger with his helmet as he took it off. There was another remark in the book, made by the actor Fred Ward, along the lines that NASA kind of let Grissom take the heat for the loss of the spacecraft, this is something that had never crossed my mind before. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 02-06-2013 12:56 PM
quote:
Originally posted by robsouth:
Thirdly, that tests had been carried out afterwards by Sam Beddingfield that proved that a malfunction could blow the hatch by accident. Under what conditions could this occur?
This is what I was referring to in my original post. As far as I'm aware just what the exact nature of these two malfunctions were have never been revealed by Sam Beddingfield. |
Rusty B
Member Posts: 239
From: Sacramento, CA
Registered: Oct 2004
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posted 02-06-2013 02:37 PM
If they found something wrong with the Liberty Bell 7 explosive hatch mechanism, what changes were made to prevent a similar event on Friendship 7 and later missions? |
Rusty B
Member Posts: 239
From: Sacramento, CA
Registered: Oct 2004
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posted 02-06-2013 11:55 PM
Project Mercury Status Report No. 9 For Period Ending January 31, 1961 Two qualification test failures of the explosive hatch with a single explosive cord have occurred. The hatch is now being redesigned to fail the bolts in tension rather than by stripping the threads. Project Mercury Status Report No. 12 for Period Ending October 31, 1961 During a period between August 5, 1961 and October 12, 1961 a series of environmental tests were Conducted on the explosive hatch. Individual pieces of the mild detonation fuse (MDF) cord, detonator caps, cnd RDX lead cups were subjected to simulated altitudes of 118 miles and 135 miles and subjected to 2,000-volt +1.2 to 2.0 milliampere static discharges. No inadvertent ignition occurred. The units were then assembled into igniter assemblies and fired by pulling the lanyard. Full-order ignition occurred. Additional MDF cord was subjected to varying exposure in hydrogen peroxide. One condition resulted in a low order detonation without igniting the full length of 12 inches. Two repeats of the same condition failed to induce detonation. The MDF was reduced to puddles of lead in all of these tests. Three inert igniter assemblies were subjected to push tests with shear pin removed, with and without vacuum, and with and without "0" ring. Minimum push force was 2.63 pounds. The assembly with minimum push force was subjected to vibrations of 0.03g to 10g at frequencies from 5 to 2,000 cycles per second with no displacement of plunger noted. A loaded hatch assembly, subjected to saline solution soak, with vacuum, electrostatic shock and vibration, was degraded to the point of "no fire" due to salt concentration degrading the detonator caps. This hatch assembly was disassembled, reloaded, and subjected to a simulated launch, three orbits, and reentry temperature test conditions. Pressure altitude during the test was 240,000 feet. Upon removal from the test chamber, the hatch was subjected to a saline solution soak and repeated electrostatic discharges. No detonation occurred. The hatch was then fired by lanyard pull and normal operation occurred. |
Rusty B
Member Posts: 239
From: Sacramento, CA
Registered: Oct 2004
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posted 02-07-2013 01:40 AM
Did Grissom panic? Astronaut Heart Rates during Mercury Missions from Mercury Project Summary Including Results Of The Fourth Manned Orbital Flight May 15 and 16, 1963.Table 11-I. — Pulse Rates | Mission | SECO
(Peak) | Weightlessness
(Range) | Re-entry
(Peak) | | | | | | MR-3 | 138 | 108 to 125 | 132 | | MR-4 | 162 | 150 to 160 | 171 | | MA-6 | 114 | 88 to 114 | 134 | | MA-7 | 96 | 60 to 94 | 104 | | MA-8 | 112 | 56 to 121 | 104 | | MA-9 | 144 | 50 to 60 (sleep)
80 to 100 (awake) | 184 |
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robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 02-07-2013 07:24 AM
Following reentry Grissom said over the comms, "I'm feeling good. I'm very good, everything is fine." That does not sound like a man that's in a panicked state. Two things to note on this, firstly Cooper had a higher heart beat at this time during his mission and he didn't panic and secondly, Grissom had a history of having an abnormally high heart rate as demonstrated by the treadmill results at the Wright laboratory during the selection process. I had always believed that the most likely scenario was that Grissom had accidentally and unknowingly hit the plunger with his helmet after he had taken it off, based solely on the statement that NASA had conducted extensive tests after the mission and just couldn't get the hatch to blow. Now after finding out that he had to keep his helmet on for the comm link and with doubt thrown on the hatch, along with a few other factors that I have learnt since reading more on this subject, I now believe that Grissom probably was just sitting there when the hatch blew. It's my belief that he didn't panic and that he didn't blow the hatch in a rush to get out. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 02-07-2013 10:40 AM
The following was written by Sam Beddingfield who was a close friend of Gus Grissom. Unfortunately it doesn't go into detail as to how the hatch malfunctioned, except to say that it could. ...after a 15 minute flight, landed safely in the Atlantic Ocean about 300 miles downrange. While waiting for the helicopter to pick up the capsule to take it back to the carrier, the hatch suddenly blew. Gus was rescued from the water but the capsule sank and was lost.Gus insisted that he did not fire the hatch and an inquiry was held within our group and the conclusion was that the hatch had indeed blown by itself. To blow the hatch required a very hard strike with the back of the hand to prevent accidentally setting it off. Everyone that ever fired a hatch manually had a strike mark on the back of their hand - Gus had no such mark after he was picked up. I was a member of the inquiry team, and we found three or four different ways that the hatch could have blown by itself. Knowing Gus as well as I did, I am certain that if he had blown the hatch manually, he would have told me. |
Rusty B
Member Posts: 239
From: Sacramento, CA
Registered: Oct 2004
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posted 02-07-2013 11:25 AM
Something other than a hand could have set it off. Grissom said he had removed the foot long survival knife from its holder on the hatch. It was mounted in the same lower left, inside corner, of the hatch as the detonator switch. Just inches from it. The knife was found in the bottom of the capsule and didn't disappear with the hatch. Hitting the detonator with an object, in the bobbing capsule, would leave no mark on the hand. |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 02-07-2013 11:28 AM
As I have stated before I believe a parachute shroud line (48), a landing bag strap (24) or the line to the dye marker canister (1) snagged the outside lanyard. |
robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 02-10-2013 10:31 AM
It would be good if someone could clear up some points for me.Where was the marker dye canister located on the spacecraft? Was it deployed by the astronaut? Was it attached to the spacecraft by a wire? Also there appears to be a lot of wires, chords and lanyards in and around the spacecraft. Could someone explain what any lanyards outside of the spacecraft were for? I have read that one was for external detonation of the explosive charges, but this should have been stowed away behind a panel on the spacecraft's outside. Finally, is it true that the survival knife carried onboard was capable of cutting through the spacecrafts hull? Grissom removed this knife and stated that he placed it in a survival bag but the knife was found loose in the spacecraft after its recovery. How did it go from being inside a bag to being outside of the bag? |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 02-10-2013 12:21 PM
The dye marker appears to be attached by type III (#550) line, from the recovery compartment (top) of the spacecraft (I don't have the specs in front of me).Some have speculated that maybe the plate covering the lanyard came off during the parachute deployment or while bobbing around in the Atlantic. The mystery goes on! But I must add Grissom had no cut on his hand. As far as the knife story; the steel of the knife was stronger that the bolts that held the hatch on. Or so the story goes. |
Jim_Voce
Member Posts: 273
From:
Registered: Jul 2016
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posted 02-13-2017 11:32 PM
What has been the final say if any on the hatch door being prematurely detonated on Liberty Bell 7?And were there any technical modifications on Friendship 7's hatch to make sure the same thing did not happen again? Grissom's explanation of events seems to have held up pretty well. Namely, that he did not knowingly blow the hatch with his hand at least since his hand after the mission was in good shape with no abrasions. NASA's testing of the Mercury hatch ejection mechanism was unable to recreate what happened. There was a theory that one of the emergency lanyards outside of the capsule could have gotten pulled or tangle with the parachute shrouds. I would be interested in hearing anyone's observations. Editor's note: Threads merged. |
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