First eye view of Perseverance Landing - Amazing video

hatzisn

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JohnC

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It's strange that you don't see any flames coming out from the thruster nozzles of the descent module.
 

cklester

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It's an amazing feat. Imagine in a few decades, spaceships with human beings aboard being the first to step foot on Mars. Maybe in our lifetimes?!
 

hatzisn

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It's strange that you don't see any flames coming out from the thruster nozzles of the descent module.

This is true. I noticed this too. The fact is that you see the air flows in the big image and the two smaller ones in the left. The fact that you do not see any flames might have to do with the fact that there is no oxygen in the atmosphere of Mars and the burning of the fuel takes place in the scycranner's engine and all you can see is the expansion of the gas. But then again I might be wrong...
 

JohnC

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This is true. I noticed this too. The fact is that you see the air flows in the big image and the two smaller ones in the left. The fact that you do not see any flames might have to do with the fact that there is no oxygen in the atmosphere of Mars and the burning of the fuel takes place in the scycranner's engine and all you can see is the expansion of the gas. But then again I might be wrong...
...Or the head of the CGI team was like "Dammit, who was in charge of the rocket effects?!!"
 
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agraham

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It's strange that you don't see any flames coming out from the thruster nozzles of the descent module.
The thrusters 'burn' a hydrazine monopropellant fuel. The decomposition of hydrazine, promoted by a catalyst, is highly exothermic and produces a 1,000 °C (1,830 °F) gas that is a mixture of nitrogen, hydrogen and ammonia. So no flames, just hot gases.
 

hatzisn

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Not mine regrettably, though I would love to see it, but I've only a few years left now :(

Don't believe that. The worst mistake is believing you are about to lose a battle before the battle starts. Positive thinking is always a plus.🤺🤺

And a covid-19 joke (lower the effect of something bad on you by making it a joke): Until 2019 everybody was saying "stay away from negative people". From the beginning of 2020 they started saying "stay away from positive people". :)
 

hatzisn

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The thrusters 'burn' a hydrazine monopropellant fuel. The decomposition of hydrazine, promoted by a catalyst, is highly exothermic and produces a 1,000 °C (1,830 °F) gas that is a mixture of nitrogen, hydrogen and ammonia. So no flames, just hot gases.

@agraham what is your field of expertise? Your answer got me curious on how they control the decomposition of the monopropellant to produce different levels of thrust... Catalyst supply? Thank you for the knowledge sharing.
 
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agraham

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...produce different levels of thrust...
Just pump more or less of it into the 'combustion chamber' .
Aerojet Rocketdyne Propulsion to Enable NASA Perseverance Ro (asdnews.com)
In-Space Data Sheets 4.8.20 (satcatalog.com)

what is your field of expertise?
I graduated as an electronic engineer, but in those days it was as much electrical and mechanical engineering in practice owing to the low voltage (5v) high currents (over 100A) that our large discrete logic computers and their I/O needed. And there were no switch mode power supplies then so that power was supplied by massively heavy mains transformer based power supplies connected by large diameter copper cabling to minimise volt drop. Working on various instrumentation and control jobs I've picked up a smattering of knowledge in various other fields and am a bit of a technological magpie so if something piques my interest (like propulsion) I'll take a look to satisfy my curiosity and so add a little more to my cornucopia of knowledge.
 
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