# それを脱毛症にするためにISSから何かを捨てなければならないのですか？

Gerstは、ISSの外で故障したポンプを交換しました。私は彼らがISSの中に壊れたポンプを戻して、それを貨物カプセルの1つで地球に戻したと推測しています。

ベストアンサー

@ user3715778の答えは正しいです。捨てても地球の大気の軌道に直ちに戻る軌道の違いは十分にはありません。
vis-vivaの式を使って数学を実行しましょう：

\$\$ v ^ 2 = GM left（ frac {2} {r} – frac {1} {a}
right）\$\$

``````           periapsis       apoapsis          semi-major       periapsis
altitude (km)   altitude (km)     axis (km)        velocity (m/s)
initial        400.           400.             6778.             7668
final          80.           400.             6618.             7575

difference                                                         93

world's record                                                     45
``````

edit: Scott Manley gets about 90 m/s as
well.

According to this Quora answer the fastest thrown ball was
in Cricket with a speed of about 161 kph or about 45 m/s, which is
about half of the speed necessary to promptly de-orbit.
This would definitely shorten the time to reentry but it would be
quite a challenge while wearing a space suit!

YouTubeの Monster Slingshot New World Record Shot
をJoerg Spraveの放課後チャンネルをご覧ください。あなたは標準的な宇宙服でこれを行うことができるかもしれません

シンプルなスリングは、いくつかの詳細に応じて、おそらくそれを行うかもしれない…

However, At 400 km altitude everything could be
considered as deorbiting! Drag limits the lifetime of many
spacecraft there, and the ISS regularly boosts itself to even
maintain it’s altitude. The rate is quite variable and activity of
the Sun can heat the upper atmosphere and increase decay rate a
lot.

See all the good answers to How long does trash
jettisoned by hand from the ISS fall before burning up on
reentry?
for example. Basically, if you keep something on
the ISS
it will not de-orbit, at least until the ISS’s end of
life. However, if you toss it “overboard” it will find it’s way to
the Earth fairly quickly, and so this is done. In fact, it is done
both intentionally and unintentionally, as is explored in the
various answers to What kinds of
things have been tossed out of the ISS?

GIF：

edit: According to Scott
Manley’s video
this is ```1998-067NM 43203 ISS DEB```

Space.comの2020年2月2日の記事によると、宇宙飛行士宇宙ステーションのアンテナの修復中にロシアのSpacewalk記録を破る

This
shows a plot for a generic satellite, though each size
and shape will be different. At 400 km the reentry time ranges from
a few years to a few months depending on spacecraft shape and
example) and solar activity. More about drag in this asnwer and

This
links to a site called lizzard-tail.com where you can
try a calculation yourself. It won’t be accurate, again because
spacecraft shape and solar activity can vary, but you can play with
some general spacecraft and solar parameters there to get an idea.
The website also links to this documentation

above: borrowed from this