- 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.
- [Technician] Three, two, one.
- [Neil] That's one small step for man.
- [Technician] Let's clear the traffic for the test one.
- 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?
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.
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.
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.
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 patreon.com/everydayastronaut.
And while you're online be sure and check out
my brand new web store for shirts, hats, prints,
Grid Fin Not-A-Coasters, little moon lamps,
lots of other fun stuff,
and including all the 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.