I imagined deploying a net of some sort to get close but not extremely close.
But I guess the high velocities mean you need a really strong and light net and the rapid deceleration might damage the satellite anyway.
But I guess the high velocities mean you need a really strong and light net and the rapid deceleration might damage the satellite anyway.
There were studies on using the Shuttle to repair satellites, but aside from the maintenance mission on Hubble those plans were shelved. The cost of a new satellite was generally a lot less than the cost of a shuttle mission dedicated to repairing it, and it would often need to be dedicated due to the requirement to match orbits.
Even if the ISS released a smallsat, which it does from time to time, that doesn't help you. By the time you need to do maintenance on it, the cubesat will have dropped into a much lower orbit due to upper atmosphere effects.
The safest, and practically perhaps the only viable way for the ISS to do maintenance on orbital instruments is if they stay attached to the ISS.
Sorry to be pedantic, but modern rifle muzzle velocities are in the 1.2km/s range. Escape velocity in LEO is 11.2km/s, so your maximal closing speed is ~22.4kms. Which is maybe 1.3 orders of magnitude difference, not "quite a few". Orders of magnitude are big.
For the rest, you are right of course: we're talking closing speeds that can easily be one order of magnitude higher than rifle bullets (or armor-piercing tank projectiles, for that matter; those are at 1.7km/s or so).
Kinetic energy is ½m•v².
#ftfy
That's quite an overestimation.
Let's be generous and say a rifle bullet is 50 gram (0.05 kg) and fires at 1.1 km/s, and a communication satellite weighs 5 metric tonne (5000 kg) and escape velocity is 11 km/s. We have 5 orders of magnitude difference in mass and 1 in velocity. As momentum is m*v, total difference is 6 orders of magnitude. Kinetic energy is 1/2*m*v^2, so that gives 7 orders of magnitude difference.*
The mass of a bullet is more like 5 grams, and the mass of a satellite could be around 500,000 kg (the ISS). A quick search shows the the largest commercial communications satellite is Telstar 19V, with a mass of 7,076kg; in my first estimate I guessed 50,000kg. Finally, the closing velocity of two objects in orbit could be up to 22.4 km/s.
rifle bullet: 3×10³ J
Telstar 19V, geostationary orbit: 3.3×10¹⁰ J
Telstar 19V, geostationary transfer orbit: 3.5×10¹¹ J
ISS, LEO: 1.2×10¹³ J
hypothetical fast ISS: 1.1×10¹⁴ J
14−3 gives 11 orders of magnitude, but good luck making the ISS go that fast. Also, don’t forget to add in the kinetic energy of the net; it’s not going to be zero.
Still, even 7 orders of magnitude qualifies as ”quite a few”. You don’t need very many orders of magnitude before you have too many.
Of course you can make the statement true by changing everything it's about.
I do agree that the ISS is not usually considered to be a communications satellite (though it does have plenty of communications gear on board, including a ham radio repeater if I recall correctly). But it is a thing that we might want to deorbit one day. Since we were considering the ridiculous closing velocity of two objects that are both on escape trajectories, I figure using the ridiculous mass of the ISS was fair game too. But like I said, I originally guessed 50t, not 400t. I was thinking more about the payload capacities of launch vehicles than the satellites themselves.
Whatever mass and closing velocity you consider, 7 or 10 or 11 orders of magnitude all qualify as “quite a few” even if the velocity itself only has 1.3 orders of magnitude of difference.
And anyway, none of this matters, because the relevant OP specifically said "speed".
So the plain and obvious conclusion is: False.
what caliber do you have in mind for that?
If a zombie satellite needed to be decomissioned, could it be shot down and left for the pieces to disintergrate in the atmosphere instead?
Otherwise, you risk just creating more high-v debris. At the extreme end of this, you could trigger the Kessler Syndrome (https://en.wikipedia.org/wiki/Kessler_syndrome) and make orbit practically unusable.
In fact the Chinese satellite destruction test in 2007 was a very good example of this:
“ Anti-satellite missile tests, especially ones involving kinetic kill vehicles as in this case, contribute to the formation of orbital space debris which can remain in orbit for many years and could interfere with future space activity (Kessler syndrome).[7] This event was the second largest creation of space debris in history after Project West Ford, with more than 2,000 pieces of trackable size (golf ball size and larger) officially catalogued in the immediate aftermath, and an estimated 150,000 debris particles.[24][25] As of October 2016, a total of 3,438 pieces of debris had been detected, with 571 decayed and 2,867 still in orbit nine years after the incident.[26]
More than half of the tracked debris orbits the Earth with a mean altitude above 850 kilometres (530 mi), so they would likely remain in orbit for decades or centuries.[27] Based on 2009 and 2013 calculations of solar flux, the NASA Orbital Debris Program Office estimated that around 30% of the larger-than-10-centimeter (3.9 in) debris would still be in orbit in 2035.[28]
In April 2011, debris from the Chinese test passed 6 kilometres (3.7 mi) away from the International Space Station.[29]
As of April 2019, 3000 of the 10,000 pieces of space debris routinely tracked by the US Military as a threat to the International Space Station were known to have originated from the 2007 satellite shoot down.[30]”
https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_mi...
* not actual butter, but you get the idea, some polymer, or maybe aerogel?
As their orbit decays, they would actually need tons of fuel to accelerate and raise their orbit to reach the station, it’s totally impractical.
EDIT: not geostationary
edit: I'm the third one to say this in a span of a minute, sorry.