The Saturn V and the F-1 rocket engine

[G-MAN]

We've got an entire generation now who only knows NASA and US space travel as the Space Shuttle. What a technological marvel the Saturn V was, with its five F-1 engines. We're so used to seeing the Shuttle leap off the launch pad when those huge SRBs light off. Watch the Saturn V as it slowly and elegantly lifts off with those giant F-1 engines roaring away.

 

[Volvo_ST1]

That's slo-mo rocket porn.

 

[G-MAN]

Originally Posted By: Volvo_ST1

That's slo-mo rocket porn.

The second vid is real-time. I've seen people who are used to watching a Shuttle launch watch a real-time Saturn V launch and think it was slow-motion.

 

[Astro14]

F-1...1.5 million pounds of thrust...what a piece of engineering! I was 6 years old when men walked on the moon...and have been disappointed in the direction that NASA has taken ever since...

 

[Pablo]

I've talked with people that tested F-1's and have seen both the Shuttle and the Saturn V launch. No comparison....the Saturn moved the Richter scale. You could feel it for many miles.

 

[Volvo_ST1]

Originally Posted By: G-MAN

Originally Posted By: Volvo_ST1

That's slo-mo rocket porn.

The second vid is real-time. I've seen people who are used to watching a Shuttle launch watch a real-time Saturn V launch and think it was slow-motion.

I was talking about the first video. How you phrased your OP sounded like neither of the two videos was slo-mo.

 

[expat]

Every time I see that first Vid, and we see the letters USA pass by, I have to wonder, if in a different Time-Line, if that could have been a Swastika :-(

 

[Rick in PA]

My favorite F-1 picture: Now, that's how you build a moon-ship!

 

[jmac]

8 miles downrange, 12 miles high, vel. 4000 f/s - T+ 1m51s Light this candle!

 

[simple_gifts]

Wow, that second video brings back the memories. What was accomplished with the tools of the day is inconceivable to most people born after 1980. The nation would pause to watch these events and it unified all.

 

[G-MAN]

Originally Posted By: Rick in PA

My favorite F-1 picture: Now, that's how you build a moon-ship!

Von Braun was a genius. After WWII, the US got the best of the German rocket scientists, and Von Braun was the best of the best. An engine like the F-1 is the primary reason the Russians never sent a manned flight to the moon--they simply did not have the engineering prowess to develop and build a single chamber rocket engine of this size and power. If you look at all of the Soviet boosters of the 60s you'll see they all used multiple small rocket engines. In fact, the ill-fated N1 (their "moon rocket") used THIRTY main engines on the booster to achieve the thrust necessary for a moon launch. Controlling that many engines for thrust and gimbal with 1960s Soviet technology was virtually impossible.

 

[JHZR2]

Yeah based upon the initial phrasing I thought that both were realtime for whatever reason... Sure is neat, especially the second one in color. As a space shuttle child, I didnt know much of any different than the shuttle. Looking at its video, I cant say that it leaps off any faster/slower really.. I dont think... http://youtu.be/9rrWBZYLaXU

Originally Posted By: Pablo

I've talked with people that tested F-1's and have seen both the Shuttle and the Saturn V launch. No comparison....the Saturn moved the Richter scale. You could feel it for many miles.

But why? The shuttle orbiter's gross liftoff weight is 240k lbm. The Apollo combined command and service module seems to be 67k lbm. Sure seems that the shuttle would need more thrust and thus shake the earth more. Is it not so because of a different rocket design? Different fuel? I have to say that when in college, I was training down in Cocoa Beach and saw a launch of some sort (not shuttle) from out on the water. That is many miles away and we still felt and heard it, and it was an amazing sight. I hope to see another in person, from a little closer sometime.

 

[G-MAN]

Originally Posted By: JHZR2

Yeah based upon the initial phrasing I thought that both were realtime for whatever reason... Sure is neat, especially the second one in color. As a space shuttle child, I didnt know much of any different than the shuttle. Looking at its video, I cant say that it leaps off any faster/slower really.. I dont think... http://youtu.be/9rrWBZYLaXU

Originally Posted By: Pablo

I've talked with people that tested F-1's and have seen both the Shuttle and the Saturn V launch. No comparison....the Saturn moved the Richter scale. You could feel it for many miles.

But why? The shuttle orbiter's gross liftoff weight is 240k lbm. The Apollo combined command and service module seems to be 67k lbm. Sure seems that the shuttle would need more thrust and thus shake the earth more. Is it not so because of a different rocket design? Different fuel?

Each SRB used on the Shuttle produces almost twice as much thrust as one F-1 engine. Two SRB combined with the engines on the Shuttle itself produce more lift-off thrust than the Saturn V. The difference in sound and feel with the Saturn V is attributable to the difference between a liquid rocket engine and a solid rocket motor. The F-1 produces extremely high amplitude, low and mid frequency noise. It's a loud but deep, deep rumble that you feel as much as hear. The SRBs produce a higher frequency noise, and because of the solid propellant the sound is completely different. As for the lift-off speed, it is quite different. The Shuttle is much faster. My dad flew down to the Cape to witness the first Shuttle launch. I couldn't get away so I watched it on TV. He was in the VIP viewing area with my mother, I remember talking to him on the phone and commenting on how fast the Shuttle appeared to leave the pad and he agreed, saying that once those boosters lit the thing just shot off the pad, not easing off and gradually gaining speed like the Saturn V.

 

[G-MAN]

Here's a different camera angle on a Saturn V launch which gives a better perspective on the speed of lift off.

 

[JHZR2]

Originally Posted By: G-MAN

Each SRB used on the Shuttle produces almost twice as much thrust as one F-1 engine. Two SRB combined with the engines on the Shuttle itself produce more lift-off thrust than the Saturn V. ... As for the lift-off speed, it is quite different. The Shuttle is much faster.

Which to me means that the shuttle has a significantly higher amount of thrust to weight than the Saturn did.

 

[Rick in PA]

I understand there's a difference in the lift-off, but I wonder how much is perception. That Saturn V is so stinkin' tall, as it lifts off it takes more time to move it's own length. That may foster the image of a "slow, stately lift-off". Heck of a machine. Nice picture of the business end of the N1 (Nova? right?). It's interesting how much of the world's rocketry technology threads back to the Germans, but I wouldn't discount the Russian effort. Sergei Korolev did some pretty incredible things under some tough conditions, his story makes an interesting read.

 

[G-MAN]

Originally Posted By: JHZR2

Originally Posted By: G-MAN

Each SRB used on the Shuttle produces almost twice as much thrust as one F-1 engine. Two SRB combined with the engines on the Shuttle itself produce more lift-off thrust than the Saturn V. ... As for the lift-off speed, it is quite different. The Shuttle is much faster.

Which to me means that the shuttle has a significantly higher amount of thrust to weight than the Saturn did.

Yes, a higher thrust to weight ratio, but not higher thrust as it turns out, so what I posted above about the Shuttle having higher lift-off thrust was incorrect. Here's a pic of me in 1967 sitting in front of what I think was Apollo 4.

 

[JHZR2]

I was reading up a bit and found this from another site:

Quote:

The liftoff acceleration of a shuttle is about 7.23 m/sec, about 0.74 g, which I calculated from the total thrust of the solid rocket boosters and shutle main engines (34,000,000 Newtons, 7,725,000 pounds), applied against the weight of the entire stack of launch mass (19,570,000 Newtons, 4,400,000 pounds, or 1,995,574 kg)

http://www.bautforum.com/archive/index.php/t-3305.html FWIW.

 

[Milkman]

That is a COOL picture. Bless your parents for taking you there.

 

[JHZR2]

Originally Posted By: G-MAN

Yes, a higher thrust to weight ratio, but not higher thrust as it turns out, so what I posted above about the Shuttle having higher lift-off thrust was incorrect.

Wait, the shuttle must have greater thrust (because it is heavier) AND greater thrust to weight ratio (because it is claimed that it accelerates faster) in order to do what is claimed. If it only has more thrust because of its higher weight, and the thrust to weight was the same, all things equal, it would accelerate and launch at the same speed. Thinking it through a bit more, you really only want minimum thrust to weight to get you to escape velocity at the right point that lets you get to the orbit you want. Since I assume that the shuttle doesnt leave the way that say Apollo 11 did, it may mean that it needs to get to some velocity sooner, or something else. Im no expert. But all the same, for the heavier shuttle package to accelerate faster, it needs to have higher thrust and more thrust per unit mass.