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On a recent episode of The Late Show with Stephen Colbert, Dr. Neil deGrasse Tyson said:

And to this day NASA will still report the power of rockets in horsepower, which is completely absurd, because no matter how many horses you string together, they will not elevate into space.So it just doesn’t make any sense!

Question: Is it true? Does NASA still report the power of rockets in horsepower?

Is this in press briefings, or educational material, or scientific literature?

cued at 04:35:

uhoh
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2 Answers2

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Yes, part of NASA's function is public communication. As such they will use units such as "Aircraft Carriers" "School Buses" and "horsepower"

While not precise, expressing thrust in terms of horsepower notionally allows people to understand it more.

"What's impressive about this test is when ignited, the booster will be operating at about 3.6 million pounds of thrust, or 22 million horsepower," said Alex Priskos, manager of the SLS Boosters Office at Marshall. "This test firing is critical to enable validation of our design."

MaxD
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    Yes, for PR purposes only. – Organic Marble Mar 07 '20 at 14:05
  • I've just asked How does NASA calculate "rocket horsepower"? – uhoh Mar 07 '20 at 14:44
  • In Stack Exchange, link-only answers are discouraged. If the link breaks, the answer becomes useless. – uhoh Mar 07 '20 at 14:44
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    The content of the links is unimportant (all three mention horsepower) They're merely recent examples. If they do disappear, that may mean the answer has changed. –  Mar 07 '20 at 14:45
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    It shouldn't be necessary for each reader to go off-site three times to get the answer to the question. Link-only answers are always discouraged in SE and actively discouraged here in Space SE. It's a long-standing policy. – uhoh Mar 07 '20 at 14:49
  • The answer isn't in the links. The text you lincluded didn't answer your question.

    but as you wish @uhoh

     –  Mar 07 '20 at 17:37
  • I think "public outreach" better represents what I meant to write @OrganicMarble, do you think that clarifies it enough, or should I go further? –  Mar 07 '20 at 17:49
  • I agree that it was just for public "relate-ability". – Organic Marble Mar 07 '20 at 17:51
  • -1 Accepting because correct but maintaining down vote for now because of link-onliness and whatever this turns out to be ;-) – uhoh Mar 08 '20 at 23:29
  • Again, this isn't a link-only answer. It stands complete without the links. If a person is not going to trust that the links contain examples of NASA using horespower when talking about rocket engine output then one isn't going to trust that the text quoted from the link isn't made up. If I had found an explanation of why NASA uses it, and refused to quote i, you would have a point - but I have not. Such a quote would greatly improve this answer –  Mar 09 '20 at 06:51
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    There's a video of an airline pilot who's quite into technical things related to cars and planes, in which he calculates how many horsepowers a F-14 Tomcat has -> https://www.youtube.com/watch?v=JC-7wRmMH2g While computing horsepower for a jet plane is fun and bogus, it allows an average human to grasp to difference jet power makes when compared to propeller driven planes. So, horsepowers of a rocket may be bonkers, but it's a concept everyday people are familiar with. How powerful is the Saturn V? Very. How much? Very much. Horsepower may be a good crutch to convey the meaning of "Very much" – Dohn Joe May 12 '22 at 08:37
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Using the inappropriate unit horsepower for rocket engines has a very long tradition. When the V2 A4 rocket of WWII was presented to ignorant NSDAP government officials by the Wernher von Braun team, the only useful comparative value was horsepower known from automotive engines. A thrust value using forth units was not understood.

One offical had the very stupid idea of using rocket engines for railway locomotives.

Uwe
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    It does make one wonder about "government officials". Some things never change, irrespective of time or the politics of "government officials". Some "government officials" around the world think Covid-19 is fake, others that coal still has a future as an energy source, not to mention other misconceived ideas. If horse power is all their little uneducated or inexperienced minds can understand, talk to them about horse power. They hold the purse strings & "someone" needs finance. – Fred May 11 '22 at 17:53
  • Sandia Nation labs rocket rail test system – BrendanLuke15 May 11 '22 at 18:48
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    This is a great anecdote. Do you have a source? A quick Google didn't find anything. – paulmrest May 11 '22 at 19:31
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    I remember reading about that in a book some decades ago. I have to search about 5 books in my book shelf. – Uwe May 11 '22 at 19:37