> The cylindrical piece of space junk is made of a metallic alloy called Inconel, they added. It weighs 1.6 pounds (0.7 kg) and measures 4 inches (10 centimeters) high by 1.6 inches (4 cm) wide.
I’m no rocket scientist, but I’m pretty sure that would kill you if you got hit. Though we’ll have to run a couple more tests to be sure.
"One of the items I ordered was Inconel-X, I received a 3-inch diameter cylindrical billet of the material and took it to the machine shop to have a 3-inch piece cut off to make a bearing. The shop foreman fired up a band saw and started to cut the billet. He only managed to make a small groove in the billet before the cutting action stopped. The Inconel-X had destroyed the saw teeth in just a few seconds. The foreman then tried a large power hacksaw. Those saw teeth also disappeared. I then foolishly suggested he try cutting a chunk off with a cutting torch. He fired up his cutting torch and within a couple minutes we had a billet of metal that looked like taffy."
Edge Precision on Youtube posted some videos showing making a valve body out of Inconel. It's clearly a PITA, he indexes the insert (changes the cutting edge to a new one) for every single cut. That adds a lot of time, and a decent amount of expense (carbide cutting tool inserts are cheap, but not free).
Inconel is used in chemical plants for its extreme resistance to harsh chemicals which quickly corrode even the highest-quality stainless steels. Inconel (and its cousin, Monel) is primarily made from nickel (>70% for Inconel-X, >63% for monel). Stainless steel also incorporates about 10% nickel and 20% chromium. Nickel is very expensive, so if you can get away with using something with less nickel, you'd really prefer to! There are "recent" advances in corrosion-resistant steel with smaller amounts of nickel, like "duplex steel" - duplex 2204 is just slightly less corrosion resistant than 316 stainless, but contains 4% nickel instead of 10%.
You only use inconel when you absolutely cannot use anything less. It costs $2.50/lb compared to $0.80 for 316 and $0.40/lb for mild steel (standard run-of-the-mill steel). Not sure what 2204 costs these days, but will be somewhere between 316 and mild steel. No one wants to pay three times more for material if they don't have to, and also pay extra for specialized machinists who are confident working with a somewhat rare material.
Materials scientists are working hard to create new, cheaper alloys with high corrosion resistance, and it drives a lot of really cool new science! Over the past 1-4 years I've seen some super interesting articles here on HN about new science being discovered around this, but I can't find them at the moment.
That said, Inconel is only 4% denser than run-of-the-mill steel, so it's not going to make a difference which of these alloys fall from space onto your house or head.
You would have to have some pretty bad luck to be hit by space junk like that. Not saying it's a good thing or anything, just that the odds are pretty astronomical.
The more junk the higher the probabilities of an accident. It doesn't have to reach two digits probability for it to start to be a problem. Densely populated areas + high likelihood of space debris could lead to unacceptable risks. Although I agree the actual danger is in the orbits and with deployed satellites.
What's the smallest meteorite that would still be "penetrative" to a human body? Eg not falling space dust and also taking into account terminal velocities of smaller particles.
you are living in an ex-ww2 bunker? here in the UK it would have gone right through the roof tiles and the plasterboard of the ceiling. same for the several dutch houses i've lived in.
You can tell it’s a joke because they stated their intent to keep quiet, but didn’t. The humor comes from the surprising difference between what was stated, and reality.
> The uncontrolled disposal of the pallet, however, was not part of the original plan. It was made necessary by a disrupted spacewalking schedule following the failed launch of a Soyuz rocket in 2018, which forced NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin to make an emergency landing in the Kazakh steppe. This event led to a backlog in the disposal of such equipment. Normally, old batteries would be placed inside an HTV (H-II Transfer Vehicle) and jettisoned from the ISS to burn up on re-entry.
> However, in late 2018, an HTV departed without this battery pallet due to the rescheduled spacewalks. As the battery replacement mission continued, and with no more HTVs of the old design expected to arrive (they are being replaced by the HTV-X cargo spacecraft), the decision was made to jettison the pallet independently.
I’m also curious which part of your auto or home insurance policy may call out space junk as covered or not. Maybe similar to a plane crashing into it.
I jokingly asked my insurance company this on Twitter a few years back when there was a Chinese satellite crashing and my house was in the possible path. They actually replied and the answer is yes - I would be covered. I was surprised actually that they replied at all and that I was covered!
The previous article from when the incident had just caught NASA's attention mentioned that the homeowner intended to go after the government for costs, but explained that it could be complicated if the part turns out to be owned by JAXA, since then either the owner has to go after JAXA or NASA has to work something out with them.
The cylindrical piece of space junk is made of a metallic alloy called Inconel, they added. It weighs 1.6 pounds (0.7 kg) and measures 4 inches (10 centimeters) high by 1.6 inches (4 cm) wide.
But are you allowed to sell it? I'd think it still belongs to NASA. If an airplane flies over your house and drops an engine into your back yard, you can't just auction it off but have to hand it over to the authorities. Or if someone – accidentally or not – throws his Rolex watch into your window. He'll have to pay for the damage, but the object is still his property.
Inconel is tough stuff, melting at around 1400°C. However looks like re-entry temps can range from 2,900°C to 6,650°C. I guess the question is if it's hot enough for long enough to melt a large lump. Apparently not in this case.
As evidenced in the photo, it probably did partially melt and deform; but getting hit with a slug of molten metal is unlikely to be any better of a result. What's more important here is the boiling point.
Not that much more important. Even if the metal is only liquefied, under the airflow it'll be prone to breaking into droplets with much lower terminal velocity, with much the same effect of reducing the mass that can actually hurt anyone. Unless I'm missing something big about the dynamics?
Can't they aim a bit better while jettisoning stuff or is re-entry that chaotic? It looks like they are relying on stuff burning off as they go through atmosphere but I don't see how that can happen for a roundish chunk of metal. But I am no nasa engineer so who knows
The earth surface is 70% water, surely you can aim for an ocean
Atmospheric drag is the main determining factor, and the atmosphere at high levels is thin, but not particularly flat, and difficult to measure. Add in the fact that orbital objects move at ridiculous speeds, and the errors quickly add up.
> The batteries, nine in total, were released on 11 January 2021 and will undergo a natural reentry, which is now predicted for around 18:56 CET on 8 March +/- 0.4 days.
Half a day of uncertainty! This was a day before reentry!
The batteries from this incident are typically returned to Earth in a controlled manner via a cargo spacecraft, but a failed launch required an alternative plan.
> The uncontrolled disposal of the pallet, however, was not part of the original plan. It was made necessary by a disrupted spacewalking schedule following the failed launch of a Soyuz rocket in 2018, which forced NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin to make an emergency landing in the Kazakh steppe. This event led to a backlog in the disposal of such equipment. Normally, old batteries would be placed inside an HTV and jettisoned from the ISS to burn up on re-entry.
> "NASA specialists use engineering models to estimate how objects heat up and break apart during atmospheric reentry," they added. "These models require detailed input parameters and are regularly updated when debris is found to have survived atmospheric reentry to the ground."
So, yes, they do rely on stuff burning off as it goes, but with some understanding whether that should actually happen.
Yes, for big parts where they know it will come down to the surface they try to aim for water, like they do with all the rocket boosters etc.
However that's still risky, so given the choice between (fast descent and aim for ocean) and (slow descent to burn up in atmosphere) they almost always aim for the latter.
Plus you can only "aim" something like a rocket booster or a satellite that can still generate a little thrust of its own. This case was more like throwing your heavy backpack from the top of a skyscraper – 3 years ago(!!). That's impossible to control. Plus it has been an emergency solution anyway, see https://www.space.com/space-station-jettisons-huge-space-jun...
Readit News
I’m no rocket scientist, but I’m pretty sure that would kill you if you got hit. Though we’ll have to run a couple more tests to be sure.
Home owner says it tore through two floors: https://twitter.com/Alejandro0tero/status/176872903149342722...
At the Edge of Space: the X-15 Flight Program
https://en.wikipedia.org/wiki/Inconel
Fascinating stuff.
You only use inconel when you absolutely cannot use anything less. It costs $2.50/lb compared to $0.80 for 316 and $0.40/lb for mild steel (standard run-of-the-mill steel). Not sure what 2204 costs these days, but will be somewhere between 316 and mild steel. No one wants to pay three times more for material if they don't have to, and also pay extra for specialized machinists who are confident working with a somewhat rare material.
Materials scientists are working hard to create new, cheaper alloys with high corrosion resistance, and it drives a lot of really cool new science! Over the past 1-4 years I've seen some super interesting articles here on HN about new science being discovered around this, but I can't find them at the moment.
That said, Inconel is only 4% denser than run-of-the-mill steel, so it's not going to make a difference which of these alloys fall from space onto your house or head.
https://www.smithsonianmag.com/smart-news/only-person-ever-h...
What's the smallest meteorite that would still be "penetrative" to a human body? Eg not falling space dust and also taking into account terminal velocities of smaller particles.
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https://news.ycombinator.com/item?id=39636991
Also some perhaps important context:
> The uncontrolled disposal of the pallet, however, was not part of the original plan. It was made necessary by a disrupted spacewalking schedule following the failed launch of a Soyuz rocket in 2018, which forced NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin to make an emergency landing in the Kazakh steppe. This event led to a backlog in the disposal of such equipment. Normally, old batteries would be placed inside an HTV (H-II Transfer Vehicle) and jettisoned from the ISS to burn up on re-entry.
> However, in late 2018, an HTV departed without this battery pallet due to the rescheduled spacewalks. As the battery replacement mission continued, and with no more HTVs of the old design expected to arrive (they are being replaced by the HTV-X cargo spacecraft), the decision was made to jettison the pallet independently.
https://gizmodo.com/massive-iss-cargo-pallet-reentry-earth-m...
If I threw something up in the air and it landed on someone’s car, I’m pretty sure I’d have to pay for the repair.
I suspect that a plane crashing into a building also makes the airline liable for the damage.
Is it the same with the ISS given that it’s a joint project by so many space agencies and that it’s in space, i.e. outside of any territory?
For example: https://en.wikipedia.org/wiki/Kosmos_954
That's about $3-4 worth according to this:
https://www.scrapmetalbuyers.com/inconel
Probably more from other people that are way more loaded than myself.
I don't think we're paying to send junk to the ISS yet.
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The earth surface is 70% water, surely you can aim for an ocean
Atmospheric drag is the main determining factor, and the atmosphere at high levels is thin, but not particularly flat, and difficult to measure. Add in the fact that orbital objects move at ridiculous speeds, and the errors quickly add up.
> The batteries, nine in total, were released on 11 January 2021 and will undergo a natural reentry, which is now predicted for around 18:56 CET on 8 March +/- 0.4 days.
Half a day of uncertainty! This was a day before reentry!
https://www.esa.int/Space_Safety/Space_Debris/Reentry_of_Int...
The batteries from this incident are typically returned to Earth in a controlled manner via a cargo spacecraft, but a failed launch required an alternative plan.
> The uncontrolled disposal of the pallet, however, was not part of the original plan. It was made necessary by a disrupted spacewalking schedule following the failed launch of a Soyuz rocket in 2018, which forced NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin to make an emergency landing in the Kazakh steppe. This event led to a backlog in the disposal of such equipment. Normally, old batteries would be placed inside an HTV and jettisoned from the ISS to burn up on re-entry.
https://gizmodo.com/massive-iss-cargo-pallet-reentry-earth-m...
> "NASA specialists use engineering models to estimate how objects heat up and break apart during atmospheric reentry," they added. "These models require detailed input parameters and are regularly updated when debris is found to have survived atmospheric reentry to the ground."
So, yes, they do rely on stuff burning off as it goes, but with some understanding whether that should actually happen.