Episode 24: Navigating In Space - The Mechanical Universe 

For anyone who needs a summary: The video, Episode 24: Navigating In Space - The Mechanical Universe, introduces us to the topic of voyages to other planets requiring an enormous amount of energy. The amount of energy being expended can be minimized by using the same force that moves the planets through the solar system. The sun’s gravitational field is used to navigate space. The routes followed by spacecraft in artificial satellites are governed by the same rules that govern the orbits of the planets. Robert T. Mitchell went on to say, “I suppose it would be possible to fly a spacecraft on a straight line from one planet to another in the solar system”. He continues by saying it would take an exorbitant amount of propulsive capability it surely is not the best way to do it. When flying from one place to another in the solar system we use one of Kepler’s laws which tells us that planets move around the sun on ellipses and spacecraft will follow these same laws. Importantly, in order to aim toward the planets with brute force alone is missing the point entirely. The present-day navigators look to the future by the way of the past. Kepler’s three laws stated how planets orbit the sun. Newton explained why Kepler’s laws worked. Newton’s and Kepler’s laws are used as operating principles. Bill O’Neil explains the way we get a spacecraft from earth to mars is to put the spacecraft in an independent orbit around the sun that necessarily intersects the orbit of the earth and the orbit of Mars. The launch vehicle has to impart enough speed onto that spacecraft after launch so that it will leave its post from earth to mars once the launch vehicle burns out thirty minutes after liftoff. In order to travel between two posts in space, the craft coasts to its destination in orbit around the sun just as if it were a planet orbiting. The path of the spacecraft from one planet to another is called a transfer orbit. The classical transfer between two planets is referred to as the Hohman transfer. A launch that was flowed closely was when they launch from earth tangentially at the lowest point in the orbit. That is the point closest to the sun and arrived at mars at the highest point, the ample absence point (the most distant point from the sun). The problem with getting the space craft from one point to another in the solar system is that there are two-part to the problem. You have to be sure the target is within range and you have to establish the range at which you’re going to lead the target so that it doesn’t pass you before you get there. Just as Kepler’s third law fixes the length of an earth year and the length of a mars year it also dictates how long a spacecraft coasting in an orbit of its own will take to get from the earth to the position of the orbit of Mars. It takes about eight and a half months. In order for mar to be “weeding” when the craft arrives, it has to be launched when mars is forty-four degrees ahead of the earth. The alignment before was called opportunity. The opportunity is presented differently for every planet. A boost in speed creates a bigger more eccentric orbit. The first task is to escape from the parking orbit around earth. A rocket’s thrust will boost the crat into a hyperbola that drifts to infinity at just the right speed of 2.9 kilometers per second The thrust must also come at the right moment at 7:56 pm. The sun does the rest of the job, bending the trajectory into a Mars transfer orbit. If the destination is venus rather than mars, the idea is still the same, but towards the sun. Now, getting the spacecraft into the planet’s vicinity making the orbits intersect is only part of the space navigator’s challenge. The challenge is also to land the spacecraft. When all the planets align up timing is everything. For a spacecraft to visit all four on the same trip, it happens every one hundred seventy-five years. That cycle came to be in the year 1977 and both of the craft reached interstellar space. For it to happen meant escaping gravity. The principle of a gravity assist is to use the gravity of a planet to change the speed and direction of the spacecraft as it goes past the planet in reference to the sun. It really has to do with the planet’s gravitational pull that causes the assisting interaction. The rings of Saturn had countless amounts of small bodies in orbit around Saturn. The F ring was discovered in 1979 by the Pioneer eleven flyby. The key to the F-ring turned out to be the same principle that got voyager to see it. It was the principle of gravity assist. The F-ring and its shepherding rings are all in orbit around Saturn. When regarding Kepler’s third law the inner moves fastest, the ring material slower, and the outer moons slower. When a particle encounters a faster-moving moon, the moon pulls it along which speeds it and flings it into a higher orbit. It can also happen in reverse so the particle enters a lower orbit. The shepherding was already offered as a theory before the Voyager reached Saturn. It ended with talking about the most magnificent discoveries of the voyager mission was the complexity of the rings of Saturn.These are what I’ve learned from watching this video on The Universe, and the Solar system.

This is one of the best things I have ever seen in my life. I almost shed a few tears.

Absolutely well done and definitely keep it up!!! 👍👍👍👍👍

P.S. Aristarchos not only supported the heliocentric model ,but also precisely calculated the distance Earth-moon in his screaptures ~400BC

One of the best videos of this series!

Orbital transfers (6:50) and launch windows (11:30). 20:55 Rings.

Awesome

fantastic

At 9:05, the video shows a box with Kepler's Third Law written as an equation. The T in that equation is the period of the orbit, not the transit time for a spaceship in that orbit. The transit time for a Hohmann transfer orbit is _half_ the period. Also, while Earth's orbit is almost circular (e=0.01672), Mars' orbit is visibly elliptical (e=0.0934). So some Hohmann transfers between Earth and Mars are better than others, because they involve less change of gravitational potential energy with respect to the sun. This year (2018) would have been a great year to go to Mars, but we weren't ready.

Thank you for this amazing video.

This material and the whole series needs to be remastered digitally enhanced for new generations to learn from and enjoy along the the way.

How many grooves are on an average 33 rpm, 12" phonographic record? Two. One continuous groove is cut on each side. Groovy, ain't it?

Bom ! O episódio foi legal , achei interessante o uso das leis de Kepler para determinar uma órbita de transferência , mas sem dúvida a parte mais legal é quando fala do princípio da assistência gravitacional ; porque deu pra perceber claramente que as naves espaciais mais avançadas do homem ( até hoje ) não conseguem mudar sua trajetória no espaço , o que é lamentavelmente ridículo , nossas naves precisam da assistência gravitacional de planetas para isso .

23:16 A young Ed Stone

You better investigate the celestial navigation for yachtsmen. Practical navigation where the earth is the center of the universe and all heavenly bodies circle round us.

Why do they hiss and boo? What's wrong with them?

This stuff is just as cool and almost as accurate as it was in 1985 - source: a very starstruck (heh) NASA intern :)

Lol this guy is hilarious. Saturn is a record!

Also, since the planets don't orbit the sun in exactly the same plane, the departure delta-vee and the arrival delta-vee won't (in general) be bound to any particular reference plane. The velocity-change vectors have to be calculated and might point in unexpected directions. Anyone who wants a more general tutorial about elliptical transfer orbits can find one on my Facebook pages, in my Notes there. facebook.com/notes/david-sims/elliptical-transfer-orbits/210993276747/

You slighted Titan and Enceladus!

A.U. - means "astronomical units". The big triangle you see in those math problems is "delta", which means the change of something, like velocity or acceleration. Vmin and Vmax mean "velocity minimum and velocity maximum."

And yes , even people of dark age new that the Earth was a sphere orbiting the sun ,the flat Earth movement was never that strong as it is in our digital delirious days

bill o neil sounds like the narrator idk why

So technically, if we sling-shot enough Voyagers past Jupiter (probably millions, if not billions) we could de-orbit Jupiter lol.

This is so annoying. Whoever put the Annenberg Media logo at the front of these videos really made a mistake. It throws the whole audio off the video. I have watched these lectures more than once, so I know there was not always this Annenberg Media introduction. Can someone please put it back to what it was?

Caltech, Jet Propulsion Laboratory, the cerebral cortex of NASA’s Missions, the voyager was the most important mission of yours, I am the Prime Magau. In 1977 I received what you know as wow signal. It was information about space and matter. It gave me detail information about structure of solar system and it’s evolution and their next visitation. Due to my treatment in UK I was not going to do my job. In early 1980s I changed my mind, because internet was being built. The idea was when you failed to capitalise my information for mankind I can present it to others more worthy than you. I began to write to your president and head of British government. when voyager passed Uranus I sent them a letter with drawing of Neptune larger moons & cloud which was not know at that time. You programmed Voyager to take family portrait of Neptune at interval on it’s approach. Your photographs confirmed my drawing. That was confirmation of real value of my information. Since then every space mission has been re-inventing the wheel and utterly waste. Other missions have farther proved soundness my info. You won the lottery, but fail to cash and use your ticket. I can understand a corrupt system has corrupt leaders and scientist. Your science of space and matter is wrong. When scientist perpetuate lei it is inevitable for politician and people to do the same. Just to make industrial complex richer. Full information in my 1975 Bremen Summerhouse notes or by official permission / request of Madam chancellor Angela Merkel I will instruct their release

And then in 2014, some guys named "Topputo and BelBruno" come along and in a non-peer-reviewed paper propose a novel "Ballistic Capture Orbit" that somehow retroactively gets folded into the Mars InSight mission with "Trajectory Control Maneuvers" using mystery thrusters and cubesats, and Lo and Behold you get Two Opportunities to go to Mars that are in February *and* May [which piqued my interest because I have an eidactic memory for old science videos where the JPL folks clearly explain the opportunity window and before the police state we live in even made scientists lie]. This means Elon Musk can drive his Tesla Roadster by Mars in Opportunity 1 and Mars InSight in Opportunity 2 using a super-expensive and super-powerful Atlas V which is *more* powerful than the Titan Centaur they had for Viking. Now, Mars InSight was paused in 2016, it weighs less than Viking did, was sitting in storage waiting for another Opportunity, so why did NASA not use the February 2018 Opportunity on a tried-and-true Hohemann Transfer Orbit like the launch of a sportscar when they had a big expensive rocket with power to spare? Using a novel orbital transfer would risk the probe hardware. Moreover this new magical mystical Ballistic Capture Orbit doesn't get an earth rotational boost; instead, it goes out past Los Angeles using NASA graphics created in Kerbel Space Program, past Tierra del Fuego, then somehow jumps to Alaska and then passes over India...weird. So, here's what I think happened: they faked the Mars launching, with Mars Insight launched on the maiden voyage of the Falcon Heavy. The reason would be to launch a classified payload on the Atlas in May due to export restrictions on the RD-180 rocket engine used by the Atlas (the Air Force is 100% dependent on Russian rocket engines. How this came to be should be a scandal, but our media is bought and paid for by the cronies). Now, how they got the Tesla Roadster into space is anyone's guess, but I think it happened in October 2017 on a ballistic missile. It could just be the frame without any innards making it super-light.

Here is how to do the Homan Transfer calculation listed in the program.... Use the measurement of astronomical units (or “a.u.” to calculate the transfer). 1. Calculate earth-to-sun distance at the very closest point of the sun, or the periapsis point: 1 a.u 2. Then calculate the Mars-to-sun distance at the farthest point of the sun, or the apoapsis point : 1.52 a.u. 3. Add these astronomical units together: 1.00 a.u. + 1.52 a.u. = 2.52 a.u. 4. Now, using this new transfer orbit distance, the spacecraft will make a half of a revolution around the sun to create the transfer, so divide 2.52 a.u. by 2, which will give you the value of “a”, or a, which will be the final transfer orbit trajectory outcome….. 2.52 a.u. / 2 = 1.26 a.u a = 1.26 a.u. The final distance of the transfer would be 1.26 a.u., and the a represents the circumference created in the transfer orbit.

"Hey buddy! How do I get to Venus from here?" Laughed hard at that one.

Very good job,but you miss informe people : radio was invented among other things ( almost everything) by Nikola Tesla,and Aristarchos from Samos discover the helioendral planetarium 2000 years before kepler.just get an info on the subject:: the antikythera machine.

Dreadful logo and intro. Not up to today’s standards, including the script! “Without the aid of a lighthouse…” 😂

Not to blow each other up (c) Who's watching in 2022-2024?

it's all 'circ-u-lar mannnn

IMHO my favorite episode of TMU

Fantastic