How Exactly Do Planetary Flybys Work?

Vote for this video by social sharing!
The companion blog to this episode is over at Medium:

#AmyShiraTeitel #History #Spaceflight

  1. Carseye1

    Always interesting stuff. I may be weird but I really like the “vintage” stuff more. I just don’t care about Space X. Don’t know why I feel that way. Anyway, I just downloaded the audio version of your “Breaking the Chains of Gravity” and am looking forward to listening to it.

  2. Scott A. Shepler

    Great episode, never knew about the propose Apollo era Venus fly-by proposal. Thanks!

  3. wiscodisco1

    Nice video Amy, but I was hoping you’d address a question I have about gravity assist flybys… If the gravity is strong enough to speed you up on the way into the planet, why doesn’t the gravity slow you down by the same amount as you exit the planet’s pull?

  4. Anthony Russell

    This was great, I will recommend it to my co-workers.

  5. William Conrad

    A lot of information transferred to my brain from being so close to your video. Thanks

  6. tdrakce

    Nice outfit with the spiders and blue roses.

  7. Keith Thorpe

    The folks at the Outer Planets Group went to President Nixon with the plans for Voyagers 1 & 2, telling him that the last time the planets were aligned in this way, Thomas Jefferson was president. They joked that ‘He blew it’, and urged President Nixon not to blow our chance.

  8. Justin Pridham

    Amy! Your dresses are always so cute, this one with webs on it doubles for Halloween?!

  9. 6omega2

    I wish had a gravity assist and enough Delta V to visit YOUR heavenly body, honey! Okay, okay, sorry, I just couldn’t resist. Thanks for another great video and stay as brilliant as you are.

  10. Curtis Willmore

    I saw a recent story on missions to intercept multiple asteroids, take samples, and return the samples to earth. I did not understand how the probes could fly around the asteroid at multiple angles before landing. I’d love to hear your breakdown.

  11. Keith Deevy

    Hey Amy, just wondering, being a scientist, wanting to know the unknown, do you think Dr. Taylor and his colleagues have found a wormhole at Skinwalker Ranch?

  12. JM Coulon

    Play Kerbal Space Program for 10 hours and all your questions about trajectories will be answered. This game is a fantastic tool to learn space flight basics.

  13. Shivam Jaiswal

    Voyager missions are seriously underrated considering how colossal of achievements these are…

  14. Lex

    I L🌎VE IT! 😃💕🚀

  15. M T

    Good stuff. Voyager 1 an 2 are fascinating.

  16. BPS&D

    @Amy Just in case you’re interested. The Canadair Sabre in 1/48th scale is now available from Airfix.

  17. Liquid Flames

    Questions I didn’t know I had, indeed. I didn’t even think to question why we don’t use Venus assist instead of Hohmann Transfer. It makes sense, though, the way you explained it.

  18. Guitar Lab

    We just put Sir Issac Newton in the driver’s seat.

  19. Thomas

    Great explanation! thank you!

  20. david riley

    Can you get someone to help and check with the frequent distorted sound on your channel – please.
    It is either at source recording, post-p, or some upload issue. It is an uncomfortable turn-off for an awesome channel. Ta x

  21. Andreas Eldh

    May I suggest a topic for your next video? Pioneers 10 and 11, Voyagers 1 and 2 and New Horizon, the only five man made objects ever to leave the Solar System. Where are they heading and what are they bringing?

  22. Brent Boswell

    Voyager 1 had the option to visit Pluto, however the mission scientists sacrificed that opportunity in order to do the best possible flyby of Titan at Saturn. Talk about missed opportunities 😒

  23. rockyblacksmith

    I’ve wondered about whether gravity assists could and were used as breaking maneuvers, thank you so much for covering that aspect of it.

  24. Steven Clarke

    Hi Amy, nice to see you back. Another great video, thanks.

  25. David Rodriguez

    Excellent job!

  26. scuzzydirtbag

    Wow, Excellent explanation of a not-so-simple subject.

  27. Roger the gun guy

    love your videos!!!! ive missed you

  28. Nixon

    Good Tube 👍

  29. SKPjoe Coursegold

    thanks Amy.

  30. Caleb Waddell

    Nice to see the new video style. I enjoy more in-depth videos like this.

  31. Galen Thurber

    No YouTube notify, I’m belled

  32. Mark P

    I didn’t catch a thing, ‘cept a glimpse of Amy ❤️❤️❤️

  33. beresford thompson

    Once again Amy, another stand out video. I always look forward to your videos, I could listen to you all day. You are clearly very intelligent, such a great memory, professional and captivating presentation, clear speech and an obvious passion for this field. You always provide a wealth of information on all of your videos and go over and beyond and in such fine detail. Thanks for all the work you put into these videos for us. Dean.

  34. thebobs9343

    Superb channel. Or as Bogie 78 years ago said to Ingred Bergman’s character in “Casablanca”… “You… your very good!”

  35. James England

    Excellent and informative as always!

  36. potterma63

    Very well explained! Thanks for that!

  37. BurnabyAlex

    You’ve got the best videos. Keep up the good work.

  38. Benjamin

    Isn’t it when a stapler flies around Jeff Daniels to grab a pen to save Matt Damon? Yeah, I’m wicked smart.

  39. Jack Wardrop

    Brilliant stuff.

  40. Kim Smyth

    Enjoy your take on this. You are a great communicator Amy.

  41. Alain Proviste

    Harsh audio, clipping because the levels are too high.

  42. Tom Schmidt

    Interesting as always. Beomg a geezer I’m fascinated what was accomplished with extremely primitive tools mid century. Glad you covered using flybys to slow down. It is pretty counterintuitive that you need to decelerate to visit the inner planets or sun. If speeding up is a “gravity assist” what is the term when the fly by is used to slow down?

  43. Hordes Coffee


  44. Mr Smith

    Always exemplary stuff from Amy. Terrific!

  45. John RH

    Fantastic episode. I have bought both of your books because you really can tell a history of the people doing the cutting edge of scientific endeavour. I also recognise your excellent fashion sense. You make every episode a journey of intrigue and I most humbly thank you .

  46. MOJO 2112

    Love the vintage lamp Amy. I had one like that in the 70s. 🇨🇦👍

  47. David Collison

    Amy, I have learned so much from your little corner of the internet! Thank you so much for these wonderful videos.

  48. Gunny 6666666

    Very interesting topic, thanks for the time to make the vid.

  49. Aviyaytor

    Well done, Amy, and yes, i learned more than I expected.

  50. Andy Bogart

    Amy can the sun be used for gravity assist too, or is it the planets’ motions around the sun that make them better slingshots? I really enjoyed today’s video :)

  51. D. A. Soward

    Thank you, young lady!

  52. Jonathanwyoyo

    Just noticed your Project Excelsior artwork in the background from Adam Young’s score – I love it! Wish I could get my hands on a print but they seem to be limited edition.

  53. acefox1

    Nice video Amy! Only thing that I would like to see on a video on this topic are specific numbers on how much velocity a spacecraft gains when doing a flyby/slingshot/gravity assist.

    It made the concept of how these work and why they are so useful & important when I learned that Voyager 2 gained about 10 km/s at Jupiter, about 5 km/s at Saturn, about 2 km/s at Uranus, and lost about 2 km/s at Neptune.

    Keep up the good work Amy! Can’t wait for your X-Planes series!

  54. Jonathan Fitzgerald

    Thank you Amy, Pete & others! I very much appreciate the amount of time and effort you put into this channel. Looking forward to the next one.

  55. Kelly O'Connor

    Great video Amy. Now can you talk me through getting a Kerbal to Duna? That’s killing me!

  56. Nicod3m0 Otimsis

    We love your work and vids. Keep it up! :)

  57. Greg Borders

    You should partner with Scott Manley, and he could make some neat animations with Kerbal Space program to give examples of these classic space manuvers! :D

  58. Thessalin

    I loved the movie 2010 (yeah I know) just because of how they showed the gravity assist. That was fun.
    Thanks for the video and you and Pete care!

  59. The Stuport

    Love The Galaxy Gal we all know as Amy…She Is Cosmic Comfort! Cheers Everyone

  60. BedsitBob

    Gravity assist was used for the Apollo moon landings, hence the famous “free return trajectory”.

  61. Gabriel Urias

    Nice upgrade👍

  62. Jason Quick

    Id say the coolest part of all this, is now I see you on the History Channel Too! Hell Yeah space stuff. They just need a space based show with just you and Alex Fillipanko and id be content

  63. Tltnation

    I feel smarter today. You ROCK.

  64. Bosun Higgs

    The crucial phrase is “speed relative to the Sun,” otherwise some people get confused wondering why a spacecraft climbing away from a planet doesn’t lose all the speed it gained when falling in. Teacher Dude noted Heinlein’s “The Rolling Stones.” But that “gravity assist” involved a burn at perigee, thus dumping some of the mass involved during approach, as well as the value of the burn itself.


    Always amazes me they can calculate things so precisely to get to a tiny dot in space at the right speed to gently land

  66. sulijoo

    Playing KSP helps you visualise gravity assists really well. Also, don’t forget the Oberth Effect! Also known as the Manley Effect. 😜

  67. Causam

    Hi Amy,
    Vintage Space is awesome, I do enjoy your channel. You say that “vintage” is your thing and no doubt the 50s and 60s space effort was fascinating. I myself am a child of Apollo. I’m in. A friend of mine, a physics prof in Boston, told me recently that in one of his courses he talks about how designs and concepts have trended backward with the advent of SpaceX using modern technology. It had never occurred to me before. Of course he’s right when you think about it and that made me think of your channel. The entire look of the Starship and Super Heavy stack looks a whole lot like something Von Braun might have come up with. The reusability angle also I think would have appealed to Werner. If only he had had access to guidance and control systems that we have today, not to mention the alloys SpaceX is using, what might Werner have been able to do?

    Also, I think you’d look badass in one of those vintage clothing get-ups alongside a Starship! 😊

    So maybe a cool video topic might be “Would Werner Von Braun have made Starship?” That’s a lot to unpack. That’s my two cents. Thanks for the great information you supply to the public!

  68. Gary Harris

    Awesome explanation of how Flyby’s work!!

  69. James Frangione

    Another fine job, Amy. Really good! Thank you! ✌️❤️🍕

  70. Francis Pitts

    I love listening to you speak. Your voice is exactly what my hearing range picks up. Too many rock concerts growing up in the 70’s but the music was so good. Plus you’re smart. It’s always interesting. Whatever you’re talking about, it’s something I’m learning. I went into a completely different work environment with a different education. So I enjoy this channel.

  71. Nikki Smith

    That was great! really informative. Don’t know if it was a problem with my computer, but your audio was clipping when you spoke louder? I’ve not heard that with any of your other videos

  72. m b

    I always learn here. Thanks Amy ;)

  73. Tom Sedgman

    This is a fantastic video, thanks Amy you are teaching my son and I so much! (Also your books are awesome!)

  74. MM Goodwings

    Fantastic video! Thanks for your effort and information!❤🙏

  75. mike g

    None of this would be possible with out proper mathematics. I find Mankind’s ability to conquer such feats absolutely fascinating.

  76. rodger Rodger

    Outstanding as always. My wife and I wish you the best. Pete? Where’s that furry little space ball of fuzz? My cars are his biggest fans…..Be safe and thank you…

  77. Harrie Hausenman

    What’s with the audio? Is my codec broken or is the audio constantly clipping?!

  78. Teacher Dude

    In his 1952 book, The Rolling Stones, Robert Heinlein describes the idea of ‘gravity assist’ repeatedly. Alas, we are not about to holiday on Mars or Venus any time soon

  79. SidNightWalker

    I’ve always found that particular technology to be one of the more impressive, overall. I wish I could say that more often, but yeah, space probes are cool.

  80. dominic bender

    Everything is vert warm. Lighting, makeup, tone,

  81. Gert van den Berg

    It does seems like “gravity assist” somewhere in the title might help for more people to find the great video…

  82. Craig L. Young

    Thanks for sharing!

  83. Rainy Day

    Thanks Amy for your video

  84. Awesomus Maximus

    Great stream Amy thank you

  85. salamanderpete

    Thanks Amy – this was excellent 😃

  86. Mark Longoria

    As Marty McFly would say “woah that was heavy”!

  87. Johnny Wednesday

    Thank you Amy, I shall watch with keen interest :) (and it’s not because you’re wearing the world’s most amazing dress – it’s because your brain is delicious)

  88. MrJackHackney

    Getting Messenger and BepiColombo to Mercury are fun gravity assist trajectory’s to ponder over your next beverage. Better way to get there is to fly Jefferson Starship and do a flyby of the San Francisco Matrix. That will give you a gravity assist to get to The Doors. The flyby will lead to poems by Jim Morrison. From there you should be able to get a glimpse of the Mega Project hiding behind Simon Whistler in the background of his YouTube Channel. As you can see I am totally bonkers.

  89. Paul Marshall

    Excellent video!! Very well thought out and presented, as usual. Cheers!!

  90. Mister X

    I just made a video montage of David Bowie’s song I took a trip on a Gemini Spacecraft with Gemini clips, I was already happy, Amy uploads a new video, I feel much happier :3

  91. Benjamin Goodrich

    Oh, the beautiful ballet of physics!

  92. Michael Thompson

    Well my day just got better by quite a bit!
    Thank you so much!!
    Side note: That lamp is nice!


    Yeayyyy..Amy is back ❤️

  94. Ashish Patil


  95. FandersonUfo

    a delightful surprise on a Friday afternoon – ty Amy – 🛸👽💚

  96. Markus-Frank Jünemann

    Is it possible that some time ago you’ve switched to another microphone? There’s a lot of clipping and distortion since the last few videos… And no, it’s not my hardware…

  97. wacwebber

    Thanks Amy! That was great!

  98. nitestryker7

    New video from Amy hell yeah!

  99. M2M

    As always a really informative & polished video. You never fail to teach me something new. Thanks, Amy! :)

  100. Scot Fretwell


Comments are closed.