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The article contradicts itself about what happens to the second stage "it burns up in the atmosphere" and "deorbit and eventually splash down in the Pacific" S

The article contradicts itself about what happens to the second stage "it burns up in the atmosphere" and "deorbit and eventually splash down in the Pacific" Seems like the latter is correct (if it was going to 'burn up' why would you need to dump fuel?) - https://en.wikipedia.org/wiki/Falcon_9#Recovery_of_second_stages_and_fairings https://en.wikipedia.org/wiki/Falcon_9#Recovery_of_second_st... I guess they figure it's better to let the fuel diffuse in the atmosphere than poison the ocean, or less weight to be recovered/sink

ceejayoz 3y ago
The fuel dump is to prevent explosions before reentry that could damage the spacecraft it just delivered or create unnecessary space debris. https://sattrackcam.blogspot.com/2018/01/fuel-dump-of-zumas-falcon-9-upper-stage.html https://sattrackcam.blogspot.com/2018/01/fuel-dump-of-zumas-... > Rocket stages always carry excess fuel, as you don't want the engine to cut out prematurely by running out of fuel. So it always has a sufficient fuel margin. Once its work is done, this excess fuel is often vented, also known as "depressurization". > Depressurization and fuel venting avoids the risk of the rocket stage blowing up, for example as a result of static electricity building up in the rocket stage. You do not want your rocket stage to blow up, as it creates an uncontrolable swarm of debris and includes the risk that particles are ejected into orbits where they do not decay quickly, adding to the space debris risk. As for burning up, it's a bit of both. Some material burns up, some larger chunks splash into the ocean. Same thing happened a while back when the US dropped bits of Skylab on Australia. https://www.abc.net.au/news/2020-05-31/nasa-skylab-fell-to-earth-esperance-retrofocus/12282468 https://www.abc.net.au/news/2020-05-31/nasa-skylab-fell-to-e...

ceejayoz 3y ago

The fuel dump is to prevent explosions before reentry that could damage the spacecraft it just delivered or create unnecessary space debris. https://sattrackcam.blogspot.com/2018/01/fuel-dump-of-zumas-falcon-9-upper-stage.html https://sattrackcam.blogspot.com/2018/01/fuel-dump-of-zumas-... > Rocket stages always carry excess fuel, as you don't want the engine to cut out prematurely by running out of fuel. So it always has a sufficient fuel margin. Once its work is done, this excess fuel is often vented, also known as "depressurization". > Depressurization and fuel venting avoids the risk of the rocket stage blowing up, for example as a result of static electricity building up in the rocket stage. You do not want your rocket stage to blow up, as it creates an uncontrolable swarm of debris and includes the risk that particles are ejected into orbits where they do not decay quickly, adding to the space debris risk. As for burning up, it's a bit of both. Some material burns up, some larger chunks splash into the ocean. Same thing happened a while back when the US dropped bits of Skylab on Australia. https://www.abc.net.au/news/2020-05-31/nasa-skylab-fell-to-earth-esperance-retrofocus/12282468 https://www.abc.net.au/news/2020-05-31/nasa-skylab-fell-to-e...