- Hi it's me Tim Dodd,
the Everyday Astronaut. Climbing on top of a rocket
is still actually really nutty when you stop and think about it. I mean you're literally
riding a controlled explosion, sitting on top of a column of flames until the blue sky turns black. And because of this risky nature, it's generally considered a good idea to have a backup in case things go wrong. Welcome to launch abort systems. Most human rated vehicles
have some type of system to get crew away from a
failing rocket in a hurry, typically by pulling the crew
capsule off of the rocket with a special set of abort motors. But did you know that the United States' second crew capsule, the Gemini spacecraft had an interesting solution for getting crew away from
impending doom, an ejection seat. Well today we're gonna take a look at an engineering solution to a problem that in hindsight would've
almost certainly led to death. Oh, and there's actually a lot more to it than just the fact that
they used an ejection seat, that's only part of the equation. This one's actually a pretty big facepalm, so welcome to our first episode of biggest facepalms of
space of spaceflight history. (upbeat music) - [Technician] Three, two, one. And liftoff! - [Neil] That's one small step for man. - [Technician] Let's clear
the traffic for the test one. (beeping) - The gemini spacecraft was
certainly an important step in American spaceflight history. I mean after all it was the first capsule to fit more than one astronaut, the first capsule to rendezvous
and the first capsule that U.S. astronauts
did a space walk from. But despite all of its greatness, there is one thing clearly
missing, a launch abort tower. I mean after all, the Mercury capsule which flew right before Gemini had it's own launch abort tower. So now before we get into
why aborting from the Gemini would've almost certainly killed you, let's talk about why they
thought an ejection seat was good enough in the first place? There's three main reasons and the first one is actually
pretty counterintuitive. The Gemini launched on
top of a Titan rocket which used hypergolic propellants. And hypergolic propellants are ones that will ignite spontaneously upon mixing with each other. They're also insanely toxic,
corrosive and carcinogenic. I mean there's a reason
you got to wear this in order to handle these. I mean you can die if
you just breathe it in! But something that's kind of surprising is due to the fact that
they ignite on contact, if a propellant tank ruptures, the energy of the blast and fireball would actually be a lot less energetic than say cryogenic fuels, which means less of a need to remain inside the protective
capsule during an abort. The next reason why they
thought it was good enough is because Gemini's chief
designer, Jim Chamberlin, really didn't like big, bulky
and heavy launch abort towers. After all, he actually
wanted the Gemini capsule to be modular, and even
envisioned it landing on the moon. In order to keep the system as simple and expandable as possible, he fought to use ejection seats instead of the launch abort tower. Now this is one of those
things that sort of confuses me because the additional weight
of a launch abort tower can be offset because
it's typically ditched only a few minutes into ascent, unlike ejection seats whose weight would have
to be lugged around throughout the entire
portion of the flight. But the last reason why they opted to use ejection
seats in the first place is easily my favorite reason. They originally planned
for the Gemini capsule to land on a runway using a Rogallo wing, which was a self-inflating flexible wing. And now if something were to go wrong during this final landing phase, the astronauts could just simply eject just like a fighter pilot would. Unfortunately the wing
ended up being canceled and replaced with simple parachutes after it was unreliable to
deploy and even if it did deploy, it was really hard to control. If you want to know more
about that crazy Rogallo wing and its use in the Gemini program, my friend Amy Shira Tietel has an awesome video all about it. I mean after all, she wrote
her master's thesis on it and even has a Rogallo
wing tattooed on her arm. Okay, so now that we know why they went with an ejection
seat, let's talk about why you really, really
didn't want to use it. First off, even when
everything goes as planned with an ejection seat,
they're unbelievably violent. I mean so much so there's
actually been cases of people breaking their backs! Okay, but broken backs is a better option than dying in a fiery explosion, so let's go down the list
of other potential problems with an ejection seat. One risk was actually witnessed by John Young and Gus Grissom who watched a test of
the ejection seat system. The hatch failed to open and the seat and the dummy
punched right through the hatch. John Young, who in my opinion was easily one of the
funniest astronauts ever, turned to Gus Grissom and said, "That's a hell of a
headache, but a short one." Next, say you do make
it clear of the hatch and you've ejected clean from on top of a 33 meter tall rocket, well if the rocket happens to erupt while you're in the air
or parachuting down, it kind of seems like you'd
be showered in shrapnel and if you survive that, you'll
be walking through a toxic, corrosive and cancerous
wasteland to get to safety. Despite my objections and why this all sounds kind
of like a terrible idea, it actually went through a solid three year testing period by NASA, who found it to be quite safe
and a good, reliable option up to about 15 kilometers in altitude, but after that it's, yeah it's no good. But lastly, perhaps the most facepalmy and easily the most dangerous aspect of aborting from a Gemini capsule was something that went unnoticed until after the program ended. When NASA tested the ejection seats, they filled the capsules full of nitrogen. Well, that's great and
all, except for the fact that the Gemini's cabin was
a pure oxygen environment. Hmm, do you see where this is going? Had the astronauts needed to abort, they would've been soaking
in a pure oxygen environment for hours, and upon lighting
the rocket motors to eject, they would've likely
immediately erupted into flames. I think Thomas Stafford, said it best, "I'm glad he didn't. "Given that we'd been soaking
in pure oxygen for two hours "any spark, especially the ignition "of an ejection-seat rocket, "would have set us on fire. "We'd have been two Roman candles "shooting off into the sand
and the palmetto trees." But of course hindsight is 20/20 and this was all before the
unfortunate lessons learned during the Apollo 1 fire. But still, you have to think
this was very much overlooked. But I guess when you're in a space race, it's probably really
easy to overlook things when you're in such a hurry. Luckily, no one ever
pulled the ejection handle on any Gemini mission,
although the crew of Gemini 6 was literally fractions of a second away from pulling the handle. On December 12th, 1965, Wally
Schirra and Thomas Stafford sat in their Gemini spacecraft waiting for Gemini 7 to fly overhead for the first orbital rendezvous attempt. All went really well
up to engine ignition. The engines ran for 1.5 seconds
and then abruptly shut down, which luckily for the crew, the rocket hadn't quite left the pad yet. If it had left the pad, it would've most likely
fallen straight back down and would have probably exploded. Since the engines were running, the clock inside the
capsule started running too and the mission rules actually dictated that the commander, Wally Schirra, was supposed to pull the D-Ring that would've ejected both
him and Thomas Stafford. His instincts made him
hold back on ejecting since he didn't feel any acceleration yet. Since they hadn't left the pad, they were actually perfectly safe. Thanks to his quick gut reaction, he most likely saved Thomas
Stafford and his own life. But then they had to sit there
and wait on top of the rocket for 90 minutes before the area was safe! Man, I'll bet they were really
happy to get down after that! NASA reset Gemini 6, the
rocket was checked out and then three days later
it successfully launched and later made the first
successful rendezvous. Well, the soviets did actually rendezvous, but they didn't come this close. So yeah, come on! I mean they were beating
the United States so bad, can't they just have it? Oh and by the way, before we wrap up, did you know the Gemini spacecraft isn't the only space launch
vehicle to have ejection seats? That's right! There's actually two other
really famous spaceships that had ejection seats. NASA actually put ejection
seats on the Space Shuttle. Space Shuttle Columbia's
first four flights had ejection seats, which were deactivated by the
5th flight and later removed, freeing up a bunch of
space on the flight deck. Since there was such a limited use case considering it was super dangerous with those crazy SRB exhaust plumes, the angled main engine exhaust
plumes and the fact that only two of a possible 8
crew members could eject, it was ditched. And unfortunately, they couldn't really add
a bunch of ejection seats for the other crew members since half the crew was on the mid-deck which was below the flight deck, meaning they'd smack into
right the flight deck's floor. Luckily the space shuttle's
ejection seats were never used, but did you know the Vostok capsule, which was the Soviet
Union's first crew capsule, actually required the
use of an ejection seat in order to have a successful mission? After reentry, Vostok
would land extremely rough and would've caused serious injuries to the cosmonaut onboard. The cosmonaut would actually need to eject at seven kilometers and
parachute down to safety. The ejection seat also functioned
as a launch abort system, although it wouldn't have worked within the first 20 seconds of flight as it didn't allow for enough time for the parachutes to deploy. As a shoddy attempt to remedy this, the Soviets actually put up safety nets around the launch pad in case
the cosmonaut needed to eject. Yikes! Ejection seats worked fine
on all six Vostok missions since the Soviets used a mixed atmosphere of nitrogen and oxygen inside the Vostok, meaning the cosmonauts didn't
turn into Roman candles. Thank goodness. So what do you think? Do you think ejection seats was actually a valid option for an abort, or do you think NASA
really dodged a bullet by even allowing them in the first place? Let me know your thoughts
in the comments below. And definitely stick around, because we have a lot more really good facepalms of spaceflight
history to get to. And I owe a huge thanks
to my Patreon supporters for helping me do all of this stuff. If you want to help contribute, please head on over to
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music in all my videos. Just go to everydayastronaut.com/shop. Speaking of music, have you checked out my new
three song EP called 27 Merlins? Where I took the actual sequence of events of the Falcon Heavy test flight and I wrote music to it. That's right, when you watch that video, the video has not been edited in any way. The music was actually
written to the video. So it's a fun new way to experience the Falcon
Heavy launch again. So be sure and check it out
and share it with a friend. Thanks everybody, that's
gonna do it for me. I'm Tim Dodd, the Everyday Astronaut, bringing space down to
earth for everyday people. (dramatic music)
I can't believe the engineers left out the fact they were dealing with a pure oxygen environment when they designed the thing.
This was an excellent episode. Well done.
This was a great video. Well done.
One recommendation: in the future you might want to make sure to point out the incredible engineering skill and talent of the designers, and if a safety related system point out that this was all done in an attempt, however ill conceived, to save lives. Otherwise it kinda seems mean spirited.