The answer to the first part of When did planetary scientists realize Venus' surface pressure was almost 100x that on Earth? How did they find out? is 1967, though it was known or at least suspected to be substantially denser than Earth's for a while before that.

The answer to Launch to orbit delta-v penalty from Venus compared to Earth? will probably turn out to be some expression like "huge".


Has a hard science fiction story ever addressed a way to launch to space from the planet Venus using conventional rocket propulsion, describing how its very dense atmosphere was managed, especially after it was known that Venus' atmosphere has a density of about 7% of water in 1967 Either a really, really powerful rocket, or perhaps using a high altitude aircraft or balloon to get above most of the atmosphere?

According to this answer several years before the actual measurement in 1967 Venus' atmosphere was already suspected to be very dense.


Becalmed in Hell by Larry Niven addresses this.

The ship uses a nuclear ramjet/chemical rocket propulsion system, and the fuel is kept in a "blimp tank".

Our ship hung below the Earth-to-Venus hydrogen fuel tank, twenty miles up and all but motionless in the syrupy air. The tank, nearly empty now, made an excellent blimp. It would keep us aloft as long as the internal pressure matched the external.


Five hundred miles above us, unreachable, was the atomic ion engine that was to take us home. We couldn’t get to it on the chemical rocket alone. The rocket was for use after the air became too thin for the ramjets.


The wing ran back like a knife-edged running board, widening toward the tail until it spread into a tailfin. The two tailfins met back of the fuselage. At the tailfin tip was the ram, a big sculptured cylinder with an atomic engine inside.

Available online here: https://www.baen.com/Chapters/9781481483605/9781481483605___6.htm

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    my next question is "Is there anything that Larry Niven hasn't thought of?" – uhoh Sep 28 '19 at 3:31
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    According to isfdb.org/cgi-bin/title.cgi?54007, "Becalmed in Hell" was first published in 1965, before the timeframe indicated in the question. – Lorendiac Sep 28 '19 at 4:11
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    Interesting! It definitely features the hot dense atmosphere though. – Organic Marble Sep 28 '19 at 4:12
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    @uhoh This reminds me of something else about Niven's work. He once commented that, in his collection Tales of Known Space, three of the stories are set on Mars. All in the same future timeline he had created. But, he says, if you carefully study how Mars is described in each story, you will find differences, because he was writing those stories in the 60s and 70s, and our knowledge of the place was growing by leaps and bounds as we sent one space probe after another in that direction. He'd use new data in each story.So it feels as if the stories are set on 3 slightly different planets! – Lorendiac Sep 28 '19 at 13:02
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    He happened to be writing these when we were rapidly learning about the solar system i.e. "The Coldest Place", obsolete before publication. – Organic Marble Sep 28 '19 at 13:14

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