Why Starting A Rocket Engine Is So Hard!

Today we’re going to do a deep dive on how exactly you start a rocket engine. We’ll cover pretty much everything from a simple solid rocket motor, to all the intricacies of liquid fueled rocket engines.

We'll go over thermal conditioning the engine, the spin up process, the scary transient regions, and the actual ignition of the propellants. Then we’ll talk about some of the extra challenges like starting a rocket engine in space and then we'll go step by step through the RS-25's startup procedure.

Timestamps:
00:00 - Intro
01:55 - Recommended Pre-Requisite Knowledge
02:35 - Starting a Solid Rocket Motor
05:45 - Purging And Thermal Conditioning
13:45 - Spin Up
20:55 - Transients
24:10 - Ignition
32:40 - Starting A Rocket Engine In Space
38:20 - Step By Step Example
53:15 - Throttling And Shutdown
57:10 - Summary And Final Thoughts

-------------------------

The best place for all your space merch needs!

[austingirdner]

All of this in less than an hour is definitely not a long video.
I'm honestly impressed you were able to cram this much into an hour!

[AnthonyRBlacker]

I'm just at the beginning, but Tim, brother you have really taken your love for rockets (all of it) and come SO FAR!! You have assembled the highest production quality team of genius people and so much talent on your team Tim, wow. You're SUCH a GREAT filmmaker!! You really deserve whatever fame and glory you have gotten and will continue to get. I'm amazed every video you create for us all to enjoy free. Thank you SO much for the hard work, all the sleepless nights, the long hours, just to share your experiences and learned knowledge with us on YouTube. You're one of a kind Tim.

[AtubewatcheR]

I CANNOT believe this is free. Thank you Tim for everything you do. This is incredible and an entire generation is learning about space travel because of you. 🙏

[ShadowZone]

Me, an hour ago: "Yeah, rocket engineering is complex, I know."
Me, after watching this: "Holy cow, how did they ever manage to NOT blow up every single space shuttle on the pad?"

Great, informative content, Tim! Thanks for this.

[srun]

I'm waiter. The fact that I sort of understand the engineering behind rocket engines because of the work you do is kind of insane. This is some of the best educational content out there. Beautifully explained and produced. You are a legend, my friend. Keep up the good work

[nguyen]

Like many of you, I’ve already watched the 2 videos recommended. The “Everyday Astronaut” deserves a flight to the moon and back home safely. I’ve learned so much from this channel.

[mixsmasher]

I think we can safely say this is one of the most anticipated videos that everyone wants to watch. Thanks for all the effort you and the team put into it! 😊

[Titter]

I've been watching this channel since you were just live streaming Spacex launches from your house. To see how far you've come in such a short amount of time is quite incredible. I've learned so much in the years I've watched. Hard work surely pays off, keep it going friend.

[chilliadmiralportsmouth]

Your channel iterations since 2018 are beyond admirable, Tim. This takes the space biscuit. Well done mate.

[timpadgett]

This was exceptional Tim, thank you. I’ve been interested in these topics since I was a 6 year old boy (that adds up to a big number now) and you answered SO many questions with this it was hard to keep up with all of them. I hope you become convinced that you're the best at this. Andy freakin' Lapsa thinks so. Good enough for me.

[rogue]

Incredible video as always, Tim. The graphics used here are second to none, and your dedication to communicating the science of spaceflight to the general public is absolutely amazing. Keep it up!

[jonnylakewood]

Tim, I feel like I finely understand rocket engine power. I have been fascinated since I was a kid in the early 60's but no matter what I read, I had never really been inside a rocket engine, until now. Thank you for doing your homework and explaining it so well. Your interviews and deep-dives with rocketeers are gritty and enlightening. Also, I appreciate all the work you did to put this video together.

[lllMithrandirlll]

As an amateur rocketeer who has been attempting to make a funtional liquid fueled model rocket for 3 years now, this video is invaluable to me. Thank you so much Tim, the work you do to make this information more accessible is amazing. Keep it up.

PS: I can't wait to join you in losing our minds over the first full stack Starship launch, I'll be watching live even if I have to take an extra break at work.

[MordecaiV]

It's so rewarding to see you able to draw from your years of dedication to get the _perfect_ examples to use as B-roll/explanation shots. Great work.

[sixstringedthing]

I will never get tired of watching RS-25's spin up in slo-mo and seeing the engine bells resonating like literal bells in sympathy with the initial shockwave when the engine transitions from pre-burner to full flow. Then watching the boundary layer spread out across the nozzle wall as combustion stabilises. So impressive, I love it every time.

[rocketpunchgo]

Easily one of the best space engineering channels on YouTube ever. Keep up the great work Tim!

[SapientPearwood]

This is an awesome video, great job!! I'm a propulsion fluid dynamics expert at NASA, and I learned a bunch from this! Some of the folks I work with are involved with RS-25 startup, and it's really cool to see their work showcased so publicly like this.

Also, I'd love to see a video on engine throttling!! You could go through solid rocket grain shape, in-space thruster pulsing and impulse bits, and of course the wild world of launch vehicle engine throttling and deep throttling. Great topic to add to your growing collection of incredibly informative rocket propulsion videos.

[Rojasher]

This is why we wait so long. Thanks for the incredible quality Tim! 🚀

[TheMusaic]

Excellent work, once again! Thank you, I learned a lot!

One last thing, as a retired professional aerospace engineer, I am super-impressed with your deep dives. Takes real effort to absorb all of this material and you have real talent!

[NoahSpurrier]

Not as difficult as starting my lawnmower.