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75 votes
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Why does the ISS have to be destroyed?

The ISS is not designed to be run unmanned, entirely. The staff on board, when there are 6 astronauts, between exercise, sleeping, and maintenance get a single person-day of science work completed. (...
geoffc's user avatar
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47 votes
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What impact will the deorbiting of thousands of satellites have on the atmosphere?

Not much research has been done on this question in recent years, but some researchers are worried enough to research into wooden satellites. The question on the environmental impact of deorbiting ...
gerrit's user avatar
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45 votes
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Why would extra fuel be needed to de-orbit the ISS (if it comes to that)?

The extent of Earth's atmosphere and thus the amount of drag on the station varies greatly with solar weather; the relationship between drag and time-to-deorbit is very nonlinear. Combined, this means ...
Russell Borogove's user avatar
39 votes

Why does the ISS have to be destroyed?

Let's explore the options: Try to keep it flying: due to structural and other stress, you would need to replace parts of the ISS. You might end up with a situation like Mir where more time is spent ...
DarkDust's user avatar
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34 votes

What impact will the deorbiting of thousands of satellites have on the atmosphere?

The mass of Earth's atmosphere is 5E+18 kg and the Troposphere alone has 3/4's of that. With an average height of 13 km that makes its volume $4 \pi r^2 h$ or about 6.6E+18 m^3. If we break up one ...
uhoh's user avatar
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20 votes
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How does Spacex Crew Dragon capsule deorbit?

Crew Dragon uses the regular Draco thrusters for the deorbit burn, and in fact for any burn during a regular flight. The Superdracos are only used for launch escape. The main reason is that the ...
Jörg W Mittag's user avatar
18 votes

Why does the ISS have to be destroyed?

The problem with the ISS is that it cannot simply be left in its current orbit, because there is a (miniscule) amount of atmospheric drag acting on the structure to continually slow it down. Since the ...
MikeB's user avatar
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15 votes
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What will happen to the parts of the ISS after they burn up?

The reason for targeting "Point Nemo" is that it isn't really a point. The nearest piece of land is 2688 km away. So even if the debris is spread over a 5000 km long strip (and it will be a ...
David Hammen's user avatar
14 votes
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Is it possible for the exhaust plume of a rocket engine burning retrograde to accelerate an object into an even higher orbit?

It's theoretically possible; the velocity of the exhaust plume is around 3000 m/s (pretty close to what you'd need for a translunar injection!) and the mass flow rate is ~270 kg/s, so if a small piece ...
Russell Borogove's user avatar
13 votes
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How long can the SpaceX Starlink satellites survive before they deorbit?

Around 5 Years Starlink satellites are launched into orbits between 335 and 354 miles above the Earth. SpaceX had originally planned to fly some of their constellation at 800 miles, but petitioned ...
Dan Hanson's user avatar
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12 votes

Two week mark; has Mayak (Маяк) been spotted yet? Reflector deployed? Astronomy "ruined"?

No, the reflector hasn't been deployed. Project head, Alexander Shayenko reported about it (RUS) (ENG) today. Early report information On July 17th the team reported about possible success (RUS) (...
Евгений Новиков's user avatar
12 votes

Quickest return from stable Earth orbit to ground?

If I can weasel on the "ground" part, it looks like the Corona film buckets took only about 20 minutes from ejection from the satellite to reaching retrieval altitude on their parachutes at ...
Organic Marble's user avatar
10 votes
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Is SpaceX propulsively deorbiting a Starlink satellite already?

Yes! The current status (end of June 2019) according to a SpaceX statement via Michael Sheetz is: 45 in final orbits 5 still raising, in final orbits shortly 5 paused during raise for adjustments, ...
jkavalik's user avatar
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9 votes

Why did the MESSENGER probe get deorbited?

Why was MESSENGER deorbited? It wasn't. (The wikipedia page on MESSENGER is wrong in this regard.) MESSENGER was inserted into an orbit about Mercury with a high inclination, a high eccentricity, ...
David Hammen's user avatar
9 votes
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Is there any orbital launcher capable of removing the second stage from orbit after inserting the payload satellite into LEO?

Yes. Several Falcon 1 and Falcon 9 upper stages, after payload separation, loitered for a few months in LEO. Other upper stages have done more forceful deorbit burns, to disintegrate after only a few ...
Camille Goudeseune's user avatar
8 votes
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Can you accurately control the reentry point by deorbiting with ion propulsion?

Probably not. To control the point of reentry, you need to be able to adjust from a perigee high enough to not promptly reenter (i.e. above 200km) to one low enough to promptly reenter (i.e. below ...
Russell Borogove's user avatar
8 votes
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Calculating a de-orbit burn, is this problem written correctly?

Assume that the 0.379 m/s² / km is a unit error, and the factor is supposed to be 0.379 m/s / km. I believe this is the fundamental mistake in the problem statement. Step 1: The delta-v required is ...
Russell Borogove's user avatar
8 votes

Why does the ISS have to be destroyed?

It doesn't, not really, but there will come a time when it will simply not be worth keeping it up. Eventually the solar panels will not produce enough power, some airtight joint will break, or ...
PearsonArtPhoto's user avatar
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7 votes
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Most fuel-efficient deorbit from geostationary

This is not a complete answer as I won't be including the exact calculation needed to find out your burn time, but at least I will address the direct return vs bi elliptic approach. For a return from ...
Diego Sánchez's user avatar
6 votes
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For a given amount of fuel, what is the best de-orbit profile for the ISS?

There is no need to have a steeper angle, and in fact, that's probably counter-productive. As explained in this thorough answer; the quickest deorbit would be to have a roughly circular orbit that is ...
PearsonArtPhoto's user avatar
  • 121k
6 votes

Would it be possible to alter the orbit of one satellite, with the exhaust plume of a rocket sufficient to deorbit it?

tl;dr: It will "blow away" too quickly to gain 100 m/s necessary to promptly deorbit, but you could at least make a dent in it's lifetime this way. Starship says it will have 6 Raptor ...
uhoh's user avatar
  • 149k
6 votes

Starship deorbit process

NOTE: after doing the below sanity check I have softened my position a lot. I don't think it's completely obvious from what's publicly available how the deorbit will be conducted. A lot of the prior ...
Erin Anne's user avatar
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5 votes
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Why is "Terminator Tape" electrically conductive?

Because it's using Earth's magnetic field to create drag. It's one of several passive deorbiting systems. An electromagnetic tether uses a conductive tether to generate an electromagnetic force as ...
Schwern's user avatar
  • 8,016
5 votes
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Two week mark; has Mayak (Маяк) been spotted yet? Reflector deployed? Astronomy "ruined"?

Some breaking news on this, according to this source (not the most reputable, to be sure) the reflectors have failed to deploy. They link to this source which appears to be from the creators of Mayak,...
Cody's user avatar
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5 votes
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What was Cassini's last image?

Similar to What video or imagery was captured onboard Cassini during its descent into Saturn's atmosphere? The second answer indicates the plan was to not give priority to taking snaps during its ...
blobbymcblobby's user avatar
4 votes

Why did the MESSENGER probe get deorbited?

While the question could be marked as duplicate of Through what process does MESSENGER undergo orbital decay?, there's some hesitation to do that so I'll post an answer and also link to @DavidHammen's ...
uhoh's user avatar
  • 149k
4 votes
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Circular to elliptical orbit delta V requirements

Assuming a 400km circular starting orbit(and disregarding drag), how much delta V would be required to bring the perigee down to 0km altitude, or what equation could I use to find this out? The vis-...
uhoh's user avatar
  • 149k
4 votes

What impact will the deorbiting of thousands of satellites have on the atmosphere?

To add another perspective to the discussion: The mass fraction of the satellites consisting of materials that naturally occur in the solar system, i.e. iron, will probably not have a notable impact ...
Everyday Astronaut's user avatar
4 votes

Most fuel-efficient deorbit from geostationary

The following table provides some useful velocities Description Velocity (m/s) Difference from Circular GEO (m/s) Circular GEO Orbit 3075 0 Elliptical (100km/GEO) Apogee 1586 -1489 Elliptical (GEO/...
phil1008's user avatar
  • 5,632
4 votes

Why couldn't China's space agency do a controlled deorbit burn for the Long March 5B?

A controlled reentry comes at a cost. China and SpaceX are apparently betting that the added cost of a controlled reentry vastly outweighs the cost of debris from an uncontrolled reentry resulting in ...
David Hammen's user avatar

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