This Day in Space & Astronomy — Nov 9: Apollo 4 Debuts Saturn V, Venus Express Launches

Host 1: Welcome to This Day in Space and Astronomy. On this day, November 9th, imagine standing three miles away from a machine so unfathomably powerful that the sound waves alone are violently shaking your windows.

Host 2: Oh yeah and actually bringing the ceiling down on your head.

Host 1: Right exactly. So today we are taking you on a deep dive into how humanity pushed the absolute physical boundaries of spaceflight you know to reach the moon and to really understand our planetary neighbors.

Host 2: It is just well a master class in calculated risk and engineering breakthroughs trying to decipher those extreme environments right next door in our solar system.

Host 1: Yeah and speaking of that ceiling caving in that actually happened in 1967 AD at exactly 7 am eastern time NASA launched Apollo 4.

Host 2: Right the very first uncrewed test of the Saturn V.

Host 1: Yeah the massive 363 foot Saturn V rocket it launched from Kennedy Space Center's Launch Complex 39 and I mean the first stage alone unleashed 7.5 million pounds of thrust.

Host 2: Which is just a mind-boggling amount of power.

Host 1: It really is. And the launch commentator Jack King he literally got showered with dust and debris falling out of the ceiling in the control center just because the vibrations were so intense.

Host 2: The sheer brute force is astounding but the engineering gamble is what really stands out to me here. NASA decided to fly this rocket all up.

Host 1: All up right.

Host 2: Yeah they scrapped the planned incremental test flights every single stage of this gargantuan machine was you know entirely live on the very first try.

Host 1: I've always found that wild like testing an all up rocket is basically like trying to test the engine the transmission and the brakes of a race car for the very first time while you're already driving it at 200 miles an hour

Host 2: that is a great way to put it

Host 1: why would they even risk that

Host 2: well time constraints primarily but the gamble paid off brilliantly I mean the rocket's third stage even successfully restarted in the vacuum of space

Host 1: which is a massive engineering hurdle in zero gravity

Host 2: exactly it pushed the command module 11,200 miles high and then sent it plunging back toward Earth and nearly 25,000 miles per hour

Host 1: wow just to test the heat shield right

Host 2: yeah against those extreme lunar return temperatures and eight and a half hours later it splashed down perfectly near the USS Bennington

Host 1: which was exactly what NASA needed

Host 2: oh I mean keep in mind this launch came just months after the deadly Apollo 1 fire

Host 1: right a very dark time the program was grieving so this flawless test proved the vehicle was ready for the moon and completely restored the nation's confidence

Host 1: confidence

Host 2: it really did and mastering that kind of brute force heavy lift physics wasn't just about reaching the moon building rockets that powerful is exactly what eventually allowed us to break earth's gravity entirely

Host 1: to fling probes deep into the solar system to explore other worlds

Host 2: precisely

Host 1: which perfectly bridges us to 2005 AD

Host 2: oh yeah

Host 1: at 0333 universal time the European Space Agency launched the Venus Express from Baikonur on a Soyuz Fregat rocket

Host 2: becoming Europe's first ever Venus orbiter

Host 1: and it completely shattered expectations

Host 2: didn't they only plan for it to last a short while yeah it was built to survive just 500 Earth days but it lasted eight years

Host 1: eight years wow

Host 2: and the discoveries were huge it found a thin ozone layer intense lightning and most incredibly evidence that Venus likely had ancient oceans of water

Host 1: that is wild to think about

Host 2: it also discovered a massive double vortex swirling over the planet's south pole

Host 1: wait a double vortex like two hurricanes stacked on top of each other how does that even form

Host 2: well it's all about atmospheric dynamics Venus's's atmosphere whips around the planet much faster than the solid planet itself rotates

Host 1: okay

Host 2: and that extreme difference in speed creates these two swirling eyes of a massive storm that are permanently trapped just churning over the south pole

Host 1: okay let's unpack this because eventually this spacecraft ran out of propellant right and usually when that happens doesn't the satellite just become dead space junk floating in orbit forever why did it crash

Host 2: normally yes it would just float but they didn't just let it die by 2014 AD the mission team decided to perform these daring aero breaking dives

Host 1: aero breaking

Host 2: yeah they deliberately dropped the orbiter so it would skim through the fiery dense upper atmosphere of Venus for about 100 seconds at a time

Host 1: oh wow meaning they were literally using the friction of Venus's thick atmosphere like a giant brake pad

Host 2: exactly

Host 1: just to slow the spacecraft down and shift its orbit all without using precious fuel

Host 2: Right. And in doing so, it survived what was likely a record amount of aerodynamic pressure for a functioning orbiter.

Host 1: That is intense.

Host 2: It ultimately burned up, but it left us with a wealth of data on how a world that once held oceans of water boiled away into a runaway greenhouse effect.

Host 1: Just becoming so incredibly hot and hostile. It's a haunting mystery, really.

Host 2: Absolutely.

Host 1: well before we wrap a couple of quick extras also happening on this day in 1934 AD the legendary Carl Sagan was born

Host 2: oh who famously and correctly argued that Venus hid a hot dense atmosphere

Host 1: spot on and in 1970 AD NASA launched two bullfrogs into space to study weightlessness and inner ear balance

Host 2: from Saturn V rockets to space frogs quite a timeline

Host 1: Right.

Host 2: but I'll leave you to ponder this considering the evidence of ancient oceans Venus Express found could Venus's mysterious transformation into a toxic furnace actually serve as a cosmic cautionary tale for our own planet's atmosphere

Host 1: thanks for tuning in see you back here tomorrow