Don’t think this is quite how it works

As the European Space Agency explains, modelling is used to pick the point at which a craft will hit the upper atmosphere, and doing that at a calculated and steep angle ensures debris will fall within a certain zone.

In 2001, the Russian space station Mir reached the end of its useful life. A cargo ship docked to the craft fired its engines to take Mir out of orbit and back to Earth. Parts burned up on re-entry, while up to 25 tonnes survived, and plummeted to its watery grave at Point Nemo.

Since then, Mir has been joined by defunct satellites, rocket parts and even an automated transfer vehicle that delivered cargo to the International Space Station – an ATV called the Jules Verne.

The spacecraft that have survived space, and the fiery descent into Earth’s atmosphere, are hardy enough to resist the crushing pressure 4km (one league) down.

After re-entry there will be the occasional hole in the hull of a satellite or space station. Meaning that the pressure will quickly equalise and therefore not actually be pressure. If this didn’t happen then they’d likely bob around, wouldn’t they, rather than sinking to 4 km down?

27 thoughts on “Don’t think this is quite how it works”

  1. First thought: “One league”? Who the hell uses leagues in this day and age?

    Second thought: Oh, it’s the Jules Verne mention. Guardianistas are so predictable.

  2. Writer is Tory Shepherd, from Oz. From Wiki:

    She has described her main interests as “social justice, religion, and dodgy health treatments.”

    Just the person to write an article that possibly requires some understanding of the physics of the subject

    But then, Guardian & science live in different universes

  3. Does she advocate dodgy health treatments? And would that make her very much Guardian or just main stream female journalist?

  4. 20 thousand bastard leagues under the sodding sea. Bloody hell that’s 8 times clean through the earth or 2 1/2 times round it. What’s the more likely ?
    And 4km is only 2.4 miles so still well short of a “league”.

  5. So it probably isn’t plastic bottles floating around the Pacific, choking the turtles, but bits of satellite.
    Something should be done. At the end of the “new” Battlestar Galactica the humans send all their ships crashing into the Sun. Maybe that’s what we need to do, I’ll check my Thunderbirds dvds for tips.

  6. At the end of the “new” Battlestar Galactica the humans send all their ships crashing into the Sun. Maybe that’s what we need to do, I’ll check my Thunderbirds dvds for tips.

    Not sure if Gerry covered it, but (in the absence of science fiction) it’s really, really difficult to move stuff sunward.

  7. Meaning that the pressure will quickly equalise and therefore not actually be pressure.

    Yes, but no. The pressure is there regardless of whether your coke bottle is full of air or concrete. Below a certain depth some compounds can’t stay together and minerals change.

  8. Episode “Sun Probe” I’m thinking of PJF, where Tin Tin passes out in T3, next to a lever marked “Low Power” and “High Power”.

  9. Bloke in West London

    “occasional hole” is something of an understatement. Anything not designed for re-entry from orbit will be in thousands of bits by the time it hits the water.

  10. @BiWL
    RUD is good, but I like ‘Lithobraking’.
    It’s much the same as aerobraking, but much more vigorous, because it uses the lithosphere instead of the atmosphere for the drag.
    Tried out by a $bn NASA Mars probe, when they mixed up imperial and metric units.

  11. So he thinks that a spaceship designed to cope with the stresses involved during a launch (though except the shuttle the spacecraft will be cargo in the rocket not the launch vehicle) in to orbit, then go on to inhabit a vacuum will survive 4km underwater, which is approximately 400 atmospheres of pressure. Tell me again why they build submarines so thick?

  12. Bloke in West London

    @Tim that happened while I was studying space engineering at Uni. Needless to say it was used as an object lesson for “label your bloody units!”

    Lithobraking always makes me think of braking-via-printing-press which is a weird image…

  13. “Meaning that the pressure will quickly equalise and therefore not actually be pressure.”

    If there isn’t a hole the pressure will still equalise. Especially at depths below 1km.
    Whether or not the container will be in the same shape when that happens is another matter….

  14. @TtC and @BiWL

    When I was studying Comp Sci at university (before the Rinderpest*), a NASA probe that was lost due to mixing up of imperial and metric was used as an example of why you always need to check your inputs and assumptions when coding. Urban legend was the unfortunate programmer was Peter Norton of Norton tools and booksfame.

    *1989

  15. They might not bob – but if they didn’t they certainly wouldn’t be withstanding the pressure 4km down.

    They’d be crushed long before that.

    And its 5.5 km in a league. What are editors for?

  16. @Tim “Verne also wasn’t thinking about 20,000 down but 20,000 along…”
    ahh, years I’ve thought about that, so obvious when pointed out.

  17. BiWL “Lithobraking always makes me think of braking-via-printing-press which is a weird image…”

    does that make offset-litho a sort of skid?

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