Hurricane Hunters - https://www.hurricanehunters.com/
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole
And I’m Brian. And we’re both from Calgary, AB.
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This week in engineering news, an ocean drone collects scientific data from inside Hurricane Sam.
Hurricane sam began as a tropical wave over West Africa in the latter half of September, eventually becoming a category 4 hurricane as it continued to intensify
Once out in the Atlantic, Sam turned north and has been travelling between the North American and European continents. It didn’t make landfall and has now been reduced to a post-tropical cyclone.
Saildrone Inc and the National Oceanic and Atmospheric Administration sent an uncrewed surface vehicle into Hurricane Sam to gather video footage and other data.
I watched the video, and I never want to experience a hurricane firsthand. I mean, I already knew that, but this just confirmed
The little boat battles 15m waves and 200 kph winds. But it has a “hurricane wing” that allows it to operate in extreme winds
This boat is one of 5 that are in the Atlantic Ocean this hurricane season gathering data to better understand the physical process of hurricanes to improve storm forecasting and preparedness
Back to the uncrewed surface vehicle, which I am calling a boat. They sailed it right into the eye of the hurricane and uploaded data directly to National Oceanic and Atmospheric Administration’s laboratory.
This is a great project and a huge contribution to research in understanding how hurricanes form and travel. It reminds me of the pod that they put in the path of tornadoes in Twister. I don’t want to detract from this contribution, but until countries like the US start prioritizing evacuation assistance for those without or with less privilege, the extra time to prepare only really helps some people. 95 people died in the US from Hurricane Ida, which was, in my opinion, entirely preventable. Although not as extreme, it reminds of how during Hurricane Katrina, Amtrak offered to evacuate hundreds, if not thousands of residents on trains they were moving out of the City, but New Orleans said no thanks and the trains left empty.
Now on to this week’s engineering failure; Apollo 1.
Initially designated AS-204, it was officially named Apollo 1 in honour of the crew that died in the fire.
First crewed mission of the US Apollo program - attempting to land a man on the moon
Planned to launch at Cape Kennedy Air Force Station Launch Complex 34, now called Cape Canaveral Air Force Station, located on an island east of Orlando.
Scheduled to launch on February 21, 1967, as the first low orbital test
Virgil Grissom, Edward White, Roger Chaffee aboard
Pre-test flight launch on January 27, led to a fire sweeping through the command module, killing all three astronauts
The test was a “plugs out” test to determine whether the spacecraft would operate on internal power while detached from all cables and umbilicals
The test was considered non-hazardous because there was no fuel and all of the pyrotechnic systems were disabled
January 27, 1967 - before the fire
Astronauts entered the Apollo 204 spacecraft, attached to the Saturn rocket, on launchpad 34 at 1 pm
Grissom’s spacesuit oxygen loop had a “sour buttermilk smell”. They stopped to take a sample and then decided to continue the test
High oxygen periodically triggered the master alarm - environmental control system personnel thought the alarms were coming from crew movement and it wasn’t resolved
There were faulty communications between Grissom’s and the control room throughout the test
During the course of the test, they also experienced communications issues between operations and checkout building and the blockhouse at complex 34
These communications issues forced a hold of the countdown at 540pm
At 631pm they were about to restart the countdown when the ground instruments showed an unexplained rise in oxygen flow in the spacesuits
They thought Grissom had moved slightly
January 27, 1967 - The Fire
Four seconds later, an astronaut (they think Chaffee) announced over the intercom “Fire, I smell fire”. Two seconds later, White said “Fire in the cockpit”. The fire was also seen in mission control via the cameras
White tried to open the escape hatch which was the escape route for the module
Command module ruptured and flame and thick black smoke billowed out and filled the launch escape system above the spacecraft
Some people evacuated the launchpad and some tried to rescue the astronauts - but the intense heat and dense smoke made it very challenging
By the time the hatch was opened, all three astronauts had died. It was later determined that the primary cause of death was carbon monoxide poisoning, with thermal burns as a secondary cause.
An investigation of the fire and duplicated conditions built for further testing revealed that the fire started at one of the wire bundles on the left side of the cabin in front of Grissom’s seat
Any launches were postponed until NASA officials cleared manned flights
Teflon, which has great fire resistance, was used as a wiring jacket, but it was easily damaged, allowing for electrical shorts to occur
Due to the highly pressurized atmosphere, a spark can ignite combustibles that are a short distance away
The environmental coolant system had some leaks - the water in the coolant evaporated faster than the glycol, leaving behind a salt formation that is highly combustible
NI Side bar - glycol is flammable, especially in high concentrations. This is interesting because glycol used to be used in sprinkler systems, in low concentrations, to prevent the systems from freezing.
In prairie Canada, where we experience extreme winter temperatures, a 50/50 glycol to water concentration was common in sprinkler systems and is still common in heating systems that are exposed to freezing.
But in the late 2000s or maybe 2010, there was a fire or series of fires in California where the sprinkler system had a high concentration of glycol (something like 70 or 80) and the glycol ended up contributing to the fire, rather than limited it, leading to some major rule changes within NFPA.
Only NFPA approved glycol mixes are permitted for use in sprinkler systems. Interestingly enough, those mixes are not capable of preventing freezing below -20C and therefore we haven’t been able to use them in Canada so far.
So in Canada, specifically the prairie provinces which experience more extreme winters, a dry sprinkler system is required. This includes a series of sensors that detect a fire, which then opens a valve and allows water to flow into the piping and discharge from the applicable heads. So until a fire is detected, the pipes are empty which alleviates the risk of freezing.
Existing systems were grandfathered I believe (although I highly recommend upgrading them to no longer use glycol)
There were debris nets along the command module that prevented items from dropping into equipment areas during tests
The nets were made of nylon and highly combustible
NASA was aware of the risk but didn’t anticipate a fire during test runs so allowed the nets to remain in place on the ground with the intention of removing them before space flight
You may have picked up on this earlier as we were describing the fire event, but the hatch was complicated and not able to be opened in the 90-second benchmark for evacuation
The release valve to normalize pressure was not large enough to have any impact in the event of a fire
The hatch opened into the module, which was nearly impossible with the high cabin pressures that occurred during the fire.
The review board determined that the organizations responsible for planning, conduct and safety of the test failed to identify all of the hazards that we just mentioned
These problems existed and were made worse by governmental pressure to minimize costs and time, as well as a lack of communication between NASA and its contractors.
Recommendations for future missions
Oxygen should be restricted or controlled
Safety should be the primary design consideration
Emergency personnel should be available
The next manned mission launched on Oct 11, 1968 (Apollo 7) - included the following improvements
Onboard TV camera
S-band radio communications
Emergency oxygen masks
Less combustible materials
New system to minimize the volatility of atmospheric conditions
So there you have it, what was meant to be a non-hazardous test for the first crewed mission to the Moon, turned out to be a devastating event for NASA and space travel in general. Like all of the engineering failures we’ve covered on this show, and as tragic as it was, there is a lot to learn from not only how the fire started, but how it spread and how the rescue was mishandled.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to failurology, so more people can find it. If you want to chat with us, our Twitter handle is @failurology, you can email us at firstname.lastname@example.org, or you can connect with us on Linked In. Check out the show notes for links to all of these.
Thanks, everyone for listening. And tune in to the next episode where we’ll talk about the leaning tower of Piza. We couldn’t decide if this was an engineering failure or a marvel. So we decided to put it halfway in between the engineering marvel specials, at episode 35. Bye everyone, talk soon!