Why Rockets Don't Fly Straight Up

Why don’t rockets fly straight up? Neil deGrasse Tyson and comedian Chuck Nice explain the curious flight paths of rockets, how they get into orbit, and the Brachistochrone problem.
What are the major differences between airplanes and rockets? We discuss rocket fuel, hydrogen fuel, and when rockets execute the roll program. Learn about how rockets get into orbit and how it looks like the Bernoulli brother’s Brachistochrone problem.
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About StarTalk:
Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!
#StarTalk #neildegrassetyson
Timestamps:
00:00 - Rockets v. Airplanes
3:15 - Executing the Roll Program
5:42 - How Rockets Get Into Orbit
7:05 - The Brachistochrone Problem

[@StarTalk]

Did you watch the recent Starship test launch?

[@RiseOfTheNew]

No u missed it 😔😔

[@Meatloaf_TV]

I did and me and my friends collectively lost our minds it was one of the coolest rocket launches I have ever seen This and other rockets are what inspired me to do aerospace engineering in college right now

[@Zbezt]

In my observational understanding it was perfect aside from some electrical issues from possible internal condensation

[@Meatloaf_TV]

​@@Zbeztfar from it something went seriously wrong with the engines on the booster after hostage and we still don't know why starship was terminated

[@Zbezt]

​@@Meatloaf_TV stick to gaming and programming its evident you cant see through walls without an algorithim assist

[@beau-urns]

Sometimes I realize how much Chuck has learned… dude is VERY educated on these topics now. He’s always been bright, and now he’s bright AND educated. What’s a combo

[@mctuble]

The importance of having smart friends

[@usaintwinnin7312]

But just memorizing what someone told you doesn’t make you educated. Maybe a little more knowledgeable, but that’s it.

[@mctuble]

@@usaintwinnin7312 I definitely doesn't hurt to have people talking to you about stuff like this and making you think rather than the latest internet challenge.

[@beau-urns]

@@usaintwinnin7312 he’s not memorizing. He responds to complex prompts and even when not prompted with analysis and input It’s clear he understands, doesn’t memorize. He’s also quick AF on his feet Not sure why you’re being a hater.

[@jeffstorey9147]

Remember that his job is the play the uneducated role, and set NGT up to go on a rant. He’s a real pro at it too.

[@aaronscott1907]

I love how profound his off-the-cuff statements are: "When you're curious and you're mathematically literate and you know a little bit of physics, these questions come up in your life, and you're compelled to solve them." Perfect wording to convey why math and science are so important in a practical sense. Great episode!

[@timtim4664]

@@HopDavid It is still a step in the right direction. People think Neil is a "God of Science".... which is a step above "Bill Nye the science guy". I'm just happy the common people still look for science as an explanation to the question of "why?". He may not always be correct, but he is in the right location...because a lot of people are lost.

[@silentblackhole]

This is the first time I've ever heard of the Brachistochrone problem, and then when you flipped it up side down for the orbit solution it blew my mind! Loved it! Thanks guys

[@RollMeOne_Kenobi]

Vsauce has an excellent video about it where he goes way in depth and it honestly only gets more mind blowing lol

[@Svensk7119]

Me too! Well done, doc!

[@stephenselby4252]

Hang on. For going up, wouldn’t the rocket gain more velocity going sideways first and then flipping upward? But then it would have to overcome the friction of the denser air on the surface. Is the Brachywhatever really relevant?

[@michaelslee4336]

The Curiosity Show with Rob and Deane (in Australia) from when I was a kid did this, mind blown even back then.

[@falklumo]

@@stephenselby4252The goal is not for going up but going fast. Velocity is where the energy is needed for, height is nothing (less than 1%). But you also need the right direction if not going to the moon. And you’re right, you need to be out of atmosphere as quick as possible too or you just melt …

[@hidasineto]

The new "edited" videos are much better than the past non-edited videos. Please, keep investing on that. Love you guys! Been watching you since the big bang

[@BJSMOOVEyt]

13.8 billion years plus?!

[@gm2958]

Except they would be much better without the added “music”.

[@RandomInTheChat]

Hi guys! It's RJ,while I was watching this video I noticed something I found very relatable so I figured I'd share my thoughts and findings with you and absolutely excited to do so.I've been skateboarding for going on 30 years and I can confirm that dropping in ( rolling down) a quarter pipe ( quarter circle ramp) one definitely obtains more speed than if one was dropping in on a bank ramp (triangle ramp) that is the same height so long as all other variables are the same ,no matter what human powered vehicles happens to be their psychotic hearts desire from bikes to scooters,roller blades and my personal favorite skateboards the results are the same. As a long time and multiple account subscriber ( not great with passwords lol) and lifetime learner I want to thank you both for making learning fun and things like science and physics approachable not just for myself and my 4 boys but for so many others Thank you Neal, Thank you Chuck .I hope that you two continue to do what you do for many years to come!

[@nagasreekanth7178]

The Brachistochrone Problem is the coolest thing ever I heard in this channel

[@jesperlett]

The reason for the brachistochrone curve in space flight is not immediately obvious, however. The reason to go vertical in the beginning is to get clear of the dense atmosphere as quickly as possible to reduce drag.

[@VonJay]

I’d argue that the brachistochrone curve in space IS immediately obvious, since the craft needs to fall towards earth and the fastest way to get that started (and for efficiency reasons) is with a curve of shortest time. The curve is not practical in heavy atmosphere, and that’s exactly what they covered.

[@shrodingerschat2258]

KSP taught me that!

[@RiseOfTheNew]

Love watching star talk. Learn, laugh and get my mind blown everytime ❤❤❤

[@michaelccopelandsr7120]

As it should be ;-P

[@petergreen5337]

Well said

[@DonCarlione973]

Out of the scientists of our era I feel that Neal D. Tyson is one of the most open-minded and honest of them. He's very unbiased which is a trait of a great scientist. Nothing is impossible to him and I love how he breaks everything down for us. I have quite a bit of respect for this man I appreciate what he does and the true person that he is.

[@SunilNayak714]

Lets take a moment to appreciate the effort of Bernoulli brothers 👏

[@nickdsp8089]

For those wondering how they came up with the word 'brachistochrone'. It is from 'brachis' = 'βραχύς' in greek and its meaning is 'sort' combined with 'chrone', 'chronos' from the greek word 'χρονος' which translates to 'time'. Βραχυχρόνιο = sort time. We use this word even in the modern greek.

[@jpdemer5]

Not βράχιστος χρόνος?

[@nickdsp8089]

@@jpdemer5 maybe superlative but not used

[@Paolo_De_Leva]

_"A _*_brachistochrone curve_*_ (from Ancient Greek βράχιστος χρόνος (brákhistos khrónos) 'shortest time')..."_ From Wikipedia (en.wikipedia.org/wiki/Brachistochrone_curve)

[@nickdsp8089]

@@Paolo_De_Leva it is like : good, better, best as i said βράχιστος is superlative of ΄βραχύς not a completely new meaning. Ιnstead of βράχιστος we prefer βραχύτατος nowadays which has the same meaning. BTW the comperative is βραχύτερος

[@Paolo_De_Leva]

​@@nickdsp8089 You wrote _"maybe superlative."_ Wikipedia gives a better answer.

[@josephmarino2654]

Thanks Neil and Chuck. I always enjoy StarTalk.

[@sapelesteve]

Terrific explainer Neal! Like many others, I never knew the exact way a rocket was launched into space. Thanks & I hope that you, Chuck & your families have a terrific Turkey Day & Happy Holidays. 👍👍🦃🦃🌲🌲

[@Famezonen]

7:17 never ent to college. But Neil will always be my fav teacher. Mind boggles me in every video.

[@TonyVSTheWorld]

The illustration of the Brachistocheone curve blew my mind when you flipped over!!!! Made all the sense in the world!! Crazy!

[@bodan1196]

We Kerbals calls it a gravity turn.

[@fiercefix]

​@@bodan1196Anti gravity turn !?

[@6thdayblue59]

“Mike Drop” I’m in tears laughing……… Chuck is a legend. Thank you guys x

[@newbornmaple87]

""Bernoulli Brothers were the life of the party"! 😄

[@flyingo]

That announcer from the Hindenburg disaster was from my hometown Wichita, KS. Just a fun fact.. well, to me anyway.

[@yournway]

That was certainly one of the geekiest but most elegantly explained maths translated to actual rocket science explanation I have ever heard, even on this channel. Thank you!

[@Shaw_Cardboard_Treasures]

You know the phrase it's not rocket science. Well this makes it a lot simpler to understand and explain to even a 6yr old.

[@SoupedUpCustoms]

Chuck Nice really adds up a whole lot more to these kinds of explainer vids. More of this and chuck nice as well!

[@toon3ry]

Love and light to you and the family Neil. Condolences to you on the death of your mum❤🕊️

[@whistletutor]

I've been a space nerd my whole life and I've never heard of the Brachistochrone problem and how it relates to trajectory - that's why I love Star Talk, always something to learn!

[@henocktaddese6892]

Thank you Neil, you remind of questions we never bothered to ask, and love the mic drop! Thank you Chuck for all the fun, you never miss a beat!

[@ra2186]

08:05 There's usually not a concept completely new to me when I watch these. This fact about rocket launches blew my mind!

[@Carverman08]

Just started the episode but I know it’s going to be another great video!

[@BogdanSilviuAron]

I follow a lot of scientific channels... A lot... And always learn new things or understand the new things I've learned... But in this channel I understand everyday things, that I thought I already understood, but I find out that I was wrong, or not completely correct, and after seeing your videos I completely understand them correctly. This channel it's Unique! Thank Neil and the other guy 😜

[@danielludlow8960]

I love these explainers so much...I literally talk out loud like you can hear saying how awesome it is!

[@andrewm8429]

i was just thinking about why they roll the other day! Perfect timing!

[@Cristianotorres1998]

Wow, that’s great to learn, Thank You Neal ! 👏🏼🙏🏼

[@michaelwoo4279]

Thank you for starsplaining! Love it every time!

[@michaelccopelandsr7120]

Neil and Chuck for 2024!

[@diegofernandez4789]

Great explainer guys. Loved it!

[@markousey5564]

Wow you guys explain and simplify the science enough to make it digestible. I love the rapport and humour making it entertaining too. Simply my favourite KZbinrs. Thank you.

[@likemeordont5951]

Thanks for letting me hang out with you guys, and you know, teaching me stuff.

[@ghahrai]

Thanks Neil & Chuck . I have learned more from your explainers than i could have from a hundred books. ❤

[@Madhamz]

From one Chuck to another Chuck. Watching my two favourite shows on youtube,Inside the NBA and Star Talk.

[@brawlwith_me]

Nice new intro music my favourite was the first one you guys had used in older videos ❤

[@TheKobiDror]

Fantastic vibes between the two of you AND getting to know a little bit more each time. I didn't knew that fact and it goes straight into my useless knowledge drawer within my memory 🤓

[@peterjackson2722]

That was fascinating, thankyou!

[@kirandeepchakraborty7921]

One of the best episode ever. ⭐⭐⭐⭐

[@EdwardKilner]

Excellent. Learned stuff. BASc EE ‘71 and still love learning. Granddaughter is new Systems Design Engineering grad, now in Masters program. Third generation Engineer. My parents never met her, but would have been delighted with her and astounded by us all.

[@GAMEOVERTBH]

Short video but gold information 😜👍🏿💯

[@davidconlee2196]

That bit about the Brachristochrone problem was pretty cool

[@mattgraham5992]

Thanks again. My favorite way to start my late night.

[@helpus1456]

First time watching. I really enjoyed this segment. Didn't understand more than have of it. But, you two were fun to watch.

[@JamesWilliams-gv7zd]

I used to live in Titusville Florida. It was awesome to see and hear the the shuttle coming and going

[@eldwdubu6968]

Learn and laugh with these two. Always fun, Thanks!

[@Shaw_Cardboard_Treasures]

That was very informative. And not over my head.

[@sosheeanand3537]

This is mind blowing explanation honestly.

[@VonJay]

It’s probably one of the smoothest explanations I’ve ever heard. I didn’t have to struggle to understand anything.

[@charlessukati4866]

Brilliant lesson from these two ❤❤❤🎉🎉🎉

[@PedroFernandes1984]

I really love this channel. always learn something new, and the comunication is awesome! Congratulations!

[@mickeybrumfield764]

Long live Neil, Chuck, and Star Talk bringing us such good information about the party oriented Bernoulli brothers and rocket science. ❤

[@mglasson]

"When the pitchforks come for Elon..." 😝

[@tamirleibovich]

8:33 classic Neil/chuck good vibes 😍⭐️ love you guys !

[@thomchristensen990]

Great episode. The editing on this is superb. Thank you.

[@thomchristensen990]

Also looking forward to your year in review talk on Jan 4th at the Museum. Last year was eye opening.

[@Darren51283]

So, what do a solid fuel rocket booster and an EV battery pack have in common? Once they ignite, you can't turn them off.

[@BakedPhoria]

Background music is nice for recaps but the silence is better

[@jankostolany38]

exactly

[@akubuosamuel4194]

Today I know about brachistochrone problem and rocket trajectory. ❤❤ Thanks Sir!.

[@GAMEOVERTBH]

Great information 👌🏿100%

[@BobbyJOnline]

If we had these videos when I was a Kid in the 80’s.. I’d be GLUED to the TV 24/7

[@RodrigoM3llo]

This video gave me a completely new perspective on explaining rocket's optimal trajectory

[@alafayette1100]

Love these guys so much ❤

[@DJ-xu5fv]

Best 10 minutes of my day! Thanks guys.

[@yaelbj]

That mic drop was really good! I am very glad I watched this! 😌

[@tokonjudo]

it is heart warming when you laugh at chuck for real :)

[@Bojeezy]

Neil and Chuck need to do a standup special together. I would watch that also. Their banter is just as entertaining as the information being provided. Like they are just 2 friends talking over a cup of coffee.

[@SureshKesraniOfficial]

Amazing truly amazing discussion

[@zelmoziggy]

Apparently Tyson saw the TikTok video that incorrectly asks which path is the “shortest” among three choices for a ball to roll.

[@cliftonjohnson8069]

Great Star Talk!!!

[@Stisse12]

Best Science YT channel !

[@abelmedina-aispuro3716]

I can’t stop watching this episode. I love it

[@6dmiller]

Hmmm, for a very long time I thought a cycloid was the fastest path down a hill, but I don't remember where I got that. Glad I watched!

[@Grubik]

8:25 was the ooooooh moment for me how did i never think of that. I have had same feeling when i saw at some other video explanation of propeller as two sails on cylinder.

[@joeyannece6197]

The kids in the class were watching Challenger blow up.

[@OnceSomeFunATime]

That's the coolest thing I learned this year

[@sherwincantago6384]

Thank you!.. I learned something today. 😊

[@fiddlefiver]

I'm learning so much, Thank you 🎉

[@pratikmali9277]

I came here thinking I’d know everything he has to say about brachistochrone (because I watched about it in Vsauce) but that thing about rocket launch trajectory blew my mind 🤯

[@hassaniq0777]

​@@HopDavidas a physicist, I can say we all sometimes like to make stuff up. I made this up as well

[@VonJay]

@@HopDavidI was trying to figure out how the b problem relates and I finally figured it out though it was plainly stated in the video. I keep forgetting, even though it was explained, that to stay in orbit you have to fall to earth fast enough to keep missing it. I think the point that confused me was the frame of reference since the shuttle is no longer trying to escape earth and is just simply trying to fall toward it. So the b. problem is really about efficiency (as stated in the video) and continuously missing earth as you’re falling toward it (as fast as possible initially).

[@JKa244]

Launch trajectories are beautiful. Rocket, ballistic, air breathing - such a beautiful interplay between simple physics and more complex fluid mechanics

[@StofftiereLindner]

Love your talks

[@jamesonrichards5105]

Neil should do a video with chuck to see how much he’s actually learned. I’ve seen some other medical channels do the same with their video editors and it’s always great to watch. Either a physics, astronomy, or general knowledge questions about space.

[@gregkent8955]

Subject: roll at Shuttle launch: I was part of "lunch with an Astronaut" at Kennedy Space center a few years ago and it was with Chris Hatfield. "any questions?" he asked. I asked "Why does the Shuttle roll after launch?" Answer: The launch pad is facing the wrong way for Shuttle launches because it was orientated for rocket launches. The Tank needs to be on the Nader side for safe release. This concludes my 'explainer'. You and Chuck are a perfect match. Chuck keeps you from going too far by using humor. Keep 'em coming.

[@Goodjobeveryone]

Thank you guys!!!

[@KokoroInt]

This was awesome!

[@petergreen5337]

❤thank you very much for this beautiful lesson

[@VikingTeddy]

Oh yess! Thank you Neil. This will help my Kerbaling so much!

[@BurqueMD]

These are so wonderful, thank you!

[@kevinfletcher1999]

Even on topics I know something about, Neil always has some great facts I knew nothing about. He’s my favourite educator.

[@shantanuaphale3966]

Gr8 explanation by world's greatest of educators ❤

[@vidtrax662]

I can see how the basketball evolved to Saturn 😂😅 Always enjoyed and learnt something from your channel 👍

[@ginnyjollykidd]

Would the brachistocrone curve also relate to the teardrop shape of Rollercoaster loops? You can't make those loops circular because the curve robs the vehicle of momentum and it drops at the peak or before peak.

[@bainesystudios]

I thought that was because if it was a consistent circle we would be subject to sustained G forces throughout and heaps of people black out

[@EmpyreanLightASMR]

@@bainesystudios without googling it, that's my understanding too. it has nothing to do with momentum, it has to do with the comfort of the passengers

[@user60521123]

I’m wondering if that curve inverted is also the path of re-entry since the opposite (getting to a point with the slowest speed) is the objective?

[@nfnworldpeace1992]

@startalk now heres an interesting one! good question!

[@Xizyx]

In KSP I sometimes launch straight up for solar orbits when Kerbin's rotation lines up with my desired trajectory. Launch conditions are always ideal, however, since it is always on the equator and Kerbin has no tilt. I haven't done the math yet as to whether it is more efficient than going into a parking orbit, though.

[@Moncriefs]

"Elon knew he had to get up outta here"🤣🤣🤣🤣

[@EricDavidRocks]

Cool new music for the logo

[@no1uknugamingchannel]

4:18 Seeing those kids watching the Challenger explode reminded me of sitting in Mrs Paige's English class all excited than catastrophe happened.... We got sent home immediately after 🥺😢

[@reignorshine.]

Dayum!, that was a mic drop ,NDG Tyson with the sic one🔥

[@christianmarquez3143]

Thank you so much. Love you guys.

[@phillippolack145]

AMAZING WORK!