A Primer on Nuclear Rocket and Why They’re Awesome in Space

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There’s more on Nuclear Engines and NERVA in my companion blog post over on Discover: https://www.youtube.com/watch?v=SAHmTQWsxeM&feature=youtu.be

Thanks to Scott Manley and Matt Wood for double checking my nuclear description on this one!

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  1. John Cooke

    I see Shelby Foote in your library, brilliant man whom was able to paint beautiful pictures with words!

  2. Felgerkarb Cambodia

    Welcome back, Amy!!!! Vintage Space, ftw!!! Great vid, NERVA was an amazing program.

  3. wrightmf

    Nice job on explaining the NERVA, what SP is, and the early goals of nuclear engines particularly using the early graphics instead of new graphics (the latter would have wasted your time and take away from point of view seen in 1960s). And most value is explaining such a major program in less than 8 minutes.

  4. Trex531

    This is a pretty ilustrative video, thanks Amy! 👍

  5. 6fuelinjected9

    Thanks for doing this video! I was hopping you would do one one the nerva program. And you always make them interesting and fun to watch. Thank you again.

  6. Simon T

    Yay, I love Amy/VintageSpace! <3
    Edit- I'd be worried about what happens when the LH2 runs out, sudden loss of coolant in a high power nuclear reactor sounds like something I don't wanna be near to! D:

  7. Smith Jason

    Couldn’t they have long cables separating the propulsion parts and the living/control capsule? Like skiing with kites.
    You have two propulsion units in front of your right and left connected by long cables so you are not in the way of the exhaust. You also have additional two propulsion units trailing behind you.
    When you get to the Mars you dump the two in front of you then maneuver and land with the chemical rockets on board of the living/control capsule.
    On the way back home, you then fire up the remaining two nuclear propulsion units.
    That should be viable. Right?

  8. Hermentotip

    Missed you so much Amy! Also, i always hoped for this video :)

  9. Coondog's outdoor adventures

    Good video! Wow! shorter term 0 and low gravity missions to Mars are more plausible with the “H ” rocket lol First time watching . Thanks.

  10. Stephen Haenn

    Glad to see you back.
    Suggestion, how about doing some videos reviewing “Vintage Space” films like “Stowaway to the Moon” and “Marooned”.

  11. Paul J. Ingram

    So this a bit short of warp drive, which I always envisioned. Thanks.

  12. Frank Neugebauer

    And how exactly do we get nuclear engines into orbit without *ANY* risk of contamination?
    With engines based on fusion instead of fission, of course! It is simple like that. The bad news for all the dreamers and clickwhores out there is: it takes some decades more time. 😎
    However, good to see ya back SpaceLady.

  13. Jacob Lyman

    I was at the Nevada State Railroad Museum in Boulder City last month, and they have two of the locomotives used in the atomic rocket testing program at Jackass Flats there.

  14. Warren Thomas

    Fantastic video , glad to see you back and keeping us in the loop on space history! You rock Amy !

  15. Tristan McCarthy

    yes finally, great to see you back! Great video btw :)

  16. Bill Cook

    Love the video, but you omitted the big problem, one that is likely impossible to overcome. Rocket’s have an unfortunately tendency to occasionally malfunction and explode. Putting a meaningful about of U235 on top of something that might shoot up into the air and explode is a terrible idea. We have legitimate worries about the tiny amount of plutonium included in certain space probes. Image how much worse this issue would be with a nuclear rocket.

  17. Tom

    Amy, you are the best space historian. The best. You make Apollo, Mercury, & Gemini live again! Thanks!

  18. Alan Marston

    Hello, Welcome back. I missed your programs. Al

  19. Bill Kerman

    We do it in KSP with LV-NERV Atomic Rocket Motor

  20. Jason Sphinx

    Didn’t know @ NERVA, or Werner Von Braun estimation of Mars mission in 1981. Or anything in this vid. Vintage Space = Rock n’roll. I ♡ Rock n’roll!!!

  21. Charles Scott

    Another great informative episode. Thanks Amy!

  22. shawn quintin

    Welcome back Amy and Pete.
    Great subject.

  23. Anthony Dooley

    I wonder what kind of impact this research had on Nuclear-Electric propulsion?

  24. mcenglish

    Great episode covering a complex topic brilliantly simple…..and blooming welcome back…..with the new space race maybe Vintage and New space soon…..an avid British viewer.

  25. Sharad1a

    Yeah!!!!!! Your back finally gr8 vid thanks for coming back :)

  26. KSPTexan

    Vintage Space is back! Yay!

  27. soysmilk

    thanks for another amazing video! never knew how nuclear rockets worked before.

  28. klugshicer

    Also saying/displaying the °Fahrenheit in °Celsius would be much appreciated!

  29. 104thDIVTimberwolf

    I have a good topic that I’ve always been curious about: Why do some rockets, the Titan II, for example, ignite there engines at T-0 and lift off at T+2 or 3, while others, most notably the Saturn V, start ignition before T-0 (in the case of the Saturn V, T-9.8) to lift off at T-0?

  30. Dimm Todd

    Thank you for this incredible video, I think my wife may have understood 1/8 of what I was saying.
    I think it’s a great idea and not much more dangerous than 2 nukes and 20 tritons in an underwater sub or 2 on an aircraft carrier. Sounds safe and double should interest people but it’s all government regulated….SLS ULA Orion should I go further.But very well done in Lehman

  31. Cornelius James

    Ahhh its been so long!!!! So good to have you back filling me with information!. Welcome back :D

  32. Fahad Alharbi

    Nuclear thermal propulsion is supprier that a second stage with enriched uranium only on top of SLS can deliver 100 ton to land on the moon, and can be reused with in space fueling. Look at the NERVA program

  33. lincoln3307

    Love me some AMY T!!!!
    So glad you’re back.

  34. bmobert

    Excellent. Congrats on not getting mired in the minutia of nuclear reactions. Well done.

  35. Gary Tesla

    To Vintage Space, Nice presentation and well spoken pretty young lady.

  36. wkg19591

    Great to see you again Amy, I was actually worrying the other day that something had happened to you.
    Great content as always, keep up the good work.

  37. Kilgore Trout

    Welcome back! I’ve really missed my Vintage Space <3
    (also, the nuclear engines are definitely my favorites in KSP)

  38. Tiisiphone

    Thank you! I never heard od nuclear propulsion in such details before. Also, I’m very glad you’re back. I was afraid this channel was gone for good.

  39. devikwolf

    Great to see you back on the air with more fantastic retro space info! Nuclear rocket propulsion is probably my favorite vintage space tech.

  40. Jevon Frost

    i asked you for a video on nerva ages ago! 😀 be great if you could do a follow up with more detail. Think you missed out the fact no oxidiser is required. Great to have you back 😍

  41. Daniel Boone

    Could you do a video on Yuri Kondratyuk? The man that figured out how to get to the moon.I love your channel. Thank you for all of your work.

  42. Ty Wynans

    Really fascinating Amy, good to have you back :). You got me hooked on vintage space. I’m currently doing research on the Spiral orbiter.

  43. ralixfilm

    2 difficultys have to be solved:
    1. to control the reactor fast and percise is really difficult, nuclear plants do that really slow to be safe.
    2. back in the days corrosion was a major problem. It is hard to find a material that withsands that heat and is stable with Hydrogen.
    My propulsion professor is in love with those thermal nuclear engines.
    It would make him happy to see something like this again

  44. Michael Glass

    That’s a high quality video right there. I am sad you keep JFK’s voice from us though.

  45. Roger Barrera

    In my book yet to be published it talks about a space craft named Prometheus which would be a nuclear ion drive type of engine that could get to mars in 3 to 4 weeks or less not the 6 to 8 months on conventional systems we have currently .now at that time i had no idea of the name would be the above mentioned name or the fact that NASA was working to construct a nuclear powered ship i found out about it on the night time talk show coast to coast with G. norie & renowned physicist Dr.michio kako happened to be on saying that NASA was indeed working on a futuristic fusion craft named Prometheus it freaked me out like i was telling the future

  46. OverUnity7734

    From the information section above:
    Twitter: @t
    Her full legal name is astVintageSpace .

  47. Ryan Bell

    What’s your opinion on space tourism Amy?

  48. Dsdcain

    It’s so nice to have my favorite Canadian space nerd back on Youtube. I’ve missed your videos.
    I really do mean this in a good way. You make the topics you cover entertaining and easy to understand. *:-)*

  49. Tensile Strength

    The chemical potential energy of the hydrogen propellent in the nuclear rocket is untapped. The hydrogen is not oxidized or otherwise exothermically chemically reacted. I take it there would not be a net significant benefit in tapping that energy.
    For the specific impulse of the nuclear rocket, the mass is just the mass of the hydrogen propellant, not the tiny mass of the nuclear fuel lost to fission. When the propellent is all gone, there’s still a lot of energy in the rocket ready to heat more propellant, were more propellant to loaded. That’s not so with the chemical rocket. With the chemical rocket, when the propellant is gone, the energy is gone.

  50. stoffls

    welcome back, and great start with an interesting topic! Now I finally understand how nuclear rockets work. (Ok, understanding is too much said, rather I get the idea).

  51. emmilvonradosoft

    Good to see you back :).
    What about the low thrust ion engines?


    Welcome back.! No mention of project Orion?

  53. M W

    How clever! So, basically the nuclear reaction is to provide heat for hydrogen (versus water, as in a nuclear power plant), whose higher specific impulse makes it more efficient than conventional chemical rockets. Absolutely fascinating!

  54. Daniel Jensen

    When I saw the notification for this I thought it was a Scott Manley video because you haven’t posted in so long, haha.
    Nice video. One thing to nit-pick, aren’t hydrolox engines still considered chemical? I thought it was basically any rocket where you’re burning the fuel to generate heat/thrust.

  55. David Hahn

    I’m over here excited about her Civil War book collection by Shelby Foote.

  56. Alexander Tzalumen

    You’re a great presenter, and I hope you eventually cover the array of experimental magnetoplasma rockets.

  57. Brian Balster

    Great episode! But when i saw the title; i’d hoped (beyond hope) that it would be about Freeman Dyson’s Project Orion .
    Is there any chance of you doing an episode about REAL nuclear powered spacecraft?
    One way or another, i’m glad you (and pete) are back!

  58. Buntymac

    Only 5 countries still use the Fahrenheit scale, you may as well be telling us temperatures in gas-mark. Other than that, a tip-top video, thank you.

  59. Esa826

    Bring back the project Orion!

  60. AnimeSunglasses

    …Is there literally NOTHING Nixon didn’t frak up for us???

  61. sarcasmo57

    In my original timeline we went to Mars in 1981. I wish I could get back.

  62. princeoftonga

    YAY welcome back Amy I’ve been missing your great videos!!

  63. Krmpfpks

    Thank you so much, also for the in depth technical description. Well done! Also interesting, that you have a “full legal name”, I only have a name ;-)

  64. Lorcazoid

    Amy! It’s been so long. Good to see you!!

  65. renier gutierrez

    I tried reaching you for business inquiry, What’s your business Inquiry email address?

  66. McNulty's Sober Companion

    lol….”MAKE ROCKET GO NOW!”
    That made me laugh. :)
    I really like the work you do here. Your vids are excellent. This Astronomy Nerd enjoys them very much. Thank you.

  67. Pax Aboll

    I’m glad you’re back; thanks for all the great stuff! You explain things well, quite understandable.

  68. Dontbeweakvato

    Welcome back!! The internet just became better 😉

  69. Andriy Predmyrskyy

    man, I’ve got to ask the question.
    The hydrogen isn’t altered chemically when it comes out the other side, right?
    so, could you make an engine that uses a chemical reaction on the other side?
    nuclear core heats hydrogen, then burn with oxygen, like a nuclear-chemical engine.
    Have those ever been proposed?

  70. sulijoo

    You’ve got to get back into KSP, Amy. Play around with the Atomic Motor which is based on NERVA. 😀

  71. Archaeopteryx128

    While NERVA is cool, I prefer the sheer audacity of Orion.

  72. Calamity

    Is it bad that I just made the connection that you (Amy) are the same person that wrote one of my favorite books?
    I knew your name was Amy, I just didn’t know your full name was Amy Shira Teitel.
    I actually did an project based off your book in one of my high school English classes, and your book helped me decide that I want to be an aerospace engineer

  73. Matthew Suffidy

    I think most people pointed out the launch and space dangers of radioactive engines. There is a difference between (explosive) fission and heat expanding nuclear rockets. Project Orion was an attempt to move something with tactical nukes really.

  74. Steven Pilling

    That technology has not gone away. In fact, the means for applying it have greatly improved. It should also be noted that the efficiency of the NERVA unit was based on the ground based tests of the first working models before the project was closed down. The potential efficiency is much higher. Also; the radiation factor of the exhaust is so low that this procedure could be safely use to propel rocket vehicles directly from the ground into space.

  75. Robert Leonard

    Welcome Back 😃
    Remember, They did this with “Slide Rulers and Pencils “….

  76. Tim Higuera

    Welcome back Amy! Good to see and hear from you again! We missed you. Looking forward to your new book! Take care!

  77. RockitMan2001

    Beautiful Amy is back! Now I can binge on sci news and history again.

  78. Jesus Ramirez Romo

    Space travel really was fuked up by Nixon wasn’t it?

  79. Trumpocalypse Now

    Excellent video, and thank you for not being one of the hysterical “OMG NUKULAR!!!” folks that reject this much needed technology. If we are to colonize Mars, we will have to employ nuclear power in the process.

  80. Stephen Crawford

    Great video. Also took your recommendation and saw Apollo 11. Really a great movie.

  81. Kraktzor

    Yay new vintage space!!
    Thought you were going to talk about Orion engines for a minute. Still cool though.

  82. Alex Landherr

    At 2:30, “Tyranny of the Tsiolkovsky Rocket Equation”.

  83. Cookthefourth

    This is the stuff I want to get a Ph.D in. People scoff at wanting to combine rockets and nuclear engineering! Ahaha!

  84. kennie morash

    glad to see you back Amy. I missed your videos
    thanks for coming back to enlighten us

  85. Christopher U.S. Smith

    1:19 That oversimplification is an understatement! (But a very good one, Amy! :) )

  86. soapbxprod

    Amy, you’re a treasure. Thanks a million. Per Aspera ad Astra.

  87. The Stuport

    Love learning new things in The Vintage Space Classroom……I left an Apple for The Teacher! Cheers From Ohio…Home of Wapakoneta

  88. Natewatl

    I hope someday you will do a program that gives Freeman Dyson proper credit as a proponent of nuclear propulsion. Thank you.

  89. Zachary Forbes

    Hey lady where have you been? What’s all this about another book?
    Great to see you’re making vids again!

  90. Michael Skinner

    I am INCREDIBLY Happy you are Back! =-)
    What’s the state of the Orion project?

  91. TheRealJacob98

    Welcome back! Missed these!

  92. Born Again Maker

    Welcome Back! – I look forward to getting to your book on my Kindle list. BTW, Nice Gemini Rogallo! I don’t think I’d noticed that before.

  93. the artist

    Wow like old times!
    (hey Amy your Insta link doesn’t work : )

  94. Razorfish

    Kerbals use NERVAs every day. No big deal.

  95. Kevin Moore

    Great to have you back!
    A nit pick: the beryllium jacket is a neutron reflector, it prevents neutrons (not heat) from escaping, and so sustains the fission reaction. The control rods are boron on one side and beryllium on the other. Again, the boron is absorbing neutrons: the amount of neutron absorption is what controls the reaction, not the amount of heat absorption.
    The rotating control rods were less likely to get stuck than linear control rods, at the temperatures these were run at.
    Heat does have a controlling effect, in that thermal expansion will reduce the fuel density and so increase the critical mass and lower the reactivity, but this was not enough to save one of the experimental models, which ran out of hydrogen, blew up and spread itself over the Nevada test site.

  96. SoldatInconnus

    So while I love vintage space, I do have to disagree with the explanation given here.
    What governs rocket propulsion is momentum exchange so having a faster gas exhaust speed with a lighter gas (ie hydrogen) doesn’t necessarily give you more thrust, as for Isp, it is purely based on the exhaust speed and not the mass of the propellant!
    To achieve that high exhaust velocity, we heat and pressurize the gas and then use a convergent divergent nozzle (or de Laval nozzle) to accelerate it, whether you use a nuclear or chemical rocket!
    The reason a nuclear rocket engine is much more efficient (Isp wise) is primarily due to how you achieve that high temperature and pressure! You are using fission which is has much higher power density than a chemical reaction! This is why a nuclear bomb is such more destructive than a chemical bomb!
    Since the energy density of the chemical reaction is much lower, this is the first reason of the Isp difference. A second one is directly linked to the chemical process, in a chemical rocket, the pressure required are so high that the chemical reaction time is equal or longer than the time the fuel spends in the engine, so you do not actually use all your fuel! The big flames you see is what the engine waist! This is why hydrogen fuel is the best rocket fuel today, not because of its mass but because of the kinetics of the combustion, hydrogen has a much faster reaction time than fossil fuels so you extract proportionally more energy from the fuel that you can use before you eject it out of the engine.
    Finally, the primarily reason of the use of hydrogen for the fuel in the nuclear rocket is due to its thermal properties which optimize the heat transfer through the reactor! The key part is getting the gas as hot as possible! Even with hydrogen, the NERVA designs were planned to produce about 5 GW, which would make them the most powerful nuclear reactors in the world. If it was as easy to heat up a heavier gas we would do it as we would generate proportionally more momentum.
    Basically, it is a fight between splitting the atom and stealing electrons!

  97. defaultPenguin

    Love your videos! Glad you’re back!

  98. TheScholesie09

    2:04 The CSM Engine didnt use Hydrogen, it was hypergolic N2O4 / Aerozine 50, the 5 J2s on the second Stage and the one on the SIVB used H2/LOX. Im sure amy knows this, but the animation department made a whoopsie.

  99. willy mack

    Amy thank you I have missed you very much and have always enjoyed your very informative videos. I always wish you and your cat the best be safe be happy and I look forward to your next video.

  100. Chace Evans

    Finally understand what specific impulse is now. Thanks Amy!

Comments are closed.