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> the debris was likely closer to around ~100km in altitude. Commercial airliners fly around ~10km in altitude (Not wishing to ask the obvious, and depending o

> the debris was likely closer to around ~100km in altitude. Commercial airliners fly around ~10km in altitude (Not wishing to ask the obvious, and depending on the size of the pieces) debris at 100km altitude pretty much always ends up being debris falling through 10km ... right?

throw5959 2y ago
No, all or the absolute majority of it burns around 50km.
mrandish 2y ago
At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface. But you said "depending on the size", so let's imagine it's a different spacecraft carrying something that won't entirely burn up, like the Mir space station from several years back. In that scenario, debris from 100km will survive to pass through 10km. The point is: if the mass becomes debris >143km high traveling at >13,000 mph over the Caribbean - it doesn't pass through 10km anywhere near the Caribbean. Even though the friction causing tempered metal to glow white hot is slowing it, the trajectory is ballistic so by the time it slows enough to get that low (10km) it's hundreds or thousands of miles East from where the explosion happened (and where that airplane was). It's weird because given these orbital velocities and altitudes, our intuitions about up and down aren't very useful. Starship exploded in orbit over the Caribbean, so planes in the Caribbean were safe from falling debris. If it was Mir instead of Starship, planes hundreds or thousands miles to the East of the Caribbean would be at elevated risk. My high school astronomy teacher once said something like "Rockets don't go up to reach orbit. They go sideways. And they keep going sideways faster and faster until they're going so fast, up and down don't matter anymore." While that's hardly a scientific summary, it does give a sense of the dynamics. You'll recall that Mir was intentionally de-orbited so it would land in a desolate part of the Indian Ocean. So, did they blow it up right over the Indian Ocean? Nope. To crash it in the Indian Ocean, given the altitude and speed, they "blew it up" on the other side of Earth, like maybe over Chicago (I actually don't recall where the de-orbit began, but had to be very far away).
- logifail 2y ago
  > so by the time it slows enough to get that low (10km) it's hundreds or thousands of miles East from where the explosion was seen Appreciate that, the question would be, do we know that there won't be any aircraft at the right (wrong) altitude in that area(?!) With aircraft regularly travelling thousands of miles, would be interesting to know whether route choices are made to avoid being "under"* the track of a rocket's launch? There's apparently another video of the debris, this one appears to show very clearly that the debris is "going sideways"* rather than coming vertically down https://x.com/kristinafitzsi/status/1880032746032230515?s=61 https://x.com/kristinafitzsi/status/1880032746032230515?s=61 * apologies for the poor phrasing :)
  - mrandish 2y ago
    There are people on HN far better qualified than I to discuss both orbital mechanics and spacecraft safety assessments but I'll give it a layman's stab based purely on the high-level concepts (which is all I know). They know there's little to no risk to aircraft or people hundreds or thousands of miles to the East of a Starship RUD in orbit because they know exactly what's inside Starship and how it's built. They model how it will break up when traveling at these insane speeds and how the metal masses will melt and burn up during re-entry. They actually test this stuff in blast furnaces. It's a statistical model so it's theoretically possible a few small bits could make it to the ground on rare occasion, so we can't say debris will never happen - but there's been a lot of history and testing and the experts are confident it's extremely safe. The case of the MIR space station was very different than a Starship. MIR was built a long time ago by the Soviet Union and they used a big, heavily shielded power plant. That lead shielding was really the part that had a significant risk of not burning up fully on re-entry. Starship, Starlink satellites and other modern spacecraft are now usually designed to burn up on reentry. However, there are still some things in orbit and things we'll need to put in orbit in the future that won't entirely burn up on reentry. There will always be a very small risk of an accidental uncontrolled reentry causing a threat. However, these risks are vanishingly small both because we design these spacecraft with redundant systems and fail-safes and because Earth is mostly uninhabited oceans, much of our landmasses are unpopulated or sparely populated, even in the unlikely event one of the few spacecraft with a large mass that won't entirely burn up has failed and is de-orbiting out of control, we can still blow it up - and timing that at the right moment will still put it down in a safe place (like it did with MIR). There's no such thing as absolute 100% perfect safety. But you're far, far more likely to die from a great white shark attack than be injured by satellite debris. More to the point, a huge number of meteorites hit Earth every year and it's estimated over 17,000 survive to hit the surface. There are a bunch listed right now on eBay. Do you know anyone injured by any of the 17,000 space rocks that crashed into our planet this year or any airliners hit by one?
eps 2y ago
Apparently quite a bit of debris made it to the ground - > The locals here are pissed in Turks and Cacos. Huge dabris rained down everywhere It's from the pilot at the reddit link above. https://old.reddit.com/r/aviation/comments/1i34dki/starship_blew_up_in_front_of_us_had_to_divert/m7kgdvm/?context=3 https://old.reddit.com/r/aviation/comments/1i34dki/starship_...
- ricardobeat 2y ago
  No pictures or reports of anything falling in the Caribbean. People just love adding to the drama, they will later backtrack and explain that by “rain down” they meant the light show. It would be extremely unlikely due to the laws of physics, last time I checked they were still in effect.

throw5959 2y ago

No, all or the absolute majority of it burns around 50km.

mrandish 2y ago

At the incredible speeds Starship was moving (>13,000 mph) by the time it was over the Caribbean, debris from a Starship is expected to burn up by the time it reaches the surface. But you said "depending on the size", so let's imagine it's a different spacecraft carrying something that won't entirely burn up, like the Mir space station from several years back. In that scenario, debris from 100km will survive to pass through 10km. The point is: if the mass becomes debris >143km high traveling at >13,000 mph over the Caribbean - it doesn't pass through 10km anywhere near the Caribbean. Even though the friction causing tempered metal to glow white hot is slowing it, the trajectory is ballistic so by the time it slows enough to get that low (10km) it's hundreds or thousands of miles East from where the explosion happened (and where that airplane was). It's weird because given these orbital velocities and altitudes, our intuitions about up and down aren't very useful. Starship exploded in orbit over the Caribbean, so planes in the Caribbean were safe from falling debris. If it was Mir instead of Starship, planes hundreds or thousands miles to the East of the Caribbean would be at elevated risk. My high school astronomy teacher once said something like "Rockets don't go up to reach orbit. They go sideways. And they keep going sideways faster and faster until they're going so fast, up and down don't matter anymore." While that's hardly a scientific summary, it does give a sense of the dynamics. You'll recall that Mir was intentionally de-orbited so it would land in a desolate part of the Indian Ocean. So, did they blow it up right over the Indian Ocean? Nope. To crash it in the Indian Ocean, given the altitude and speed, they "blew it up" on the other side of Earth, like maybe over Chicago (I actually don't recall where the de-orbit began, but had to be very far away).

logifail 2y ago
> so by the time it slows enough to get that low (10km) it's hundreds or thousands of miles East from where the explosion was seen Appreciate that, the question would be, do we know that there won't be any aircraft at the right (wrong) altitude in that area(?!) With aircraft regularly travelling thousands of miles, would be interesting to know whether route choices are made to avoid being "under"* the track of a rocket's launch? There's apparently another video of the debris, this one appears to show very clearly that the debris is "going sideways"* rather than coming vertically down https://x.com/kristinafitzsi/status/1880032746032230515?s=61 https://x.com/kristinafitzsi/status/1880032746032230515?s=61 * apologies for the poor phrasing :)
- mrandish 2y ago
  There are people on HN far better qualified than I to discuss both orbital mechanics and spacecraft safety assessments but I'll give it a layman's stab based purely on the high-level concepts (which is all I know). They know there's little to no risk to aircraft or people hundreds or thousands of miles to the East of a Starship RUD in orbit because they know exactly what's inside Starship and how it's built. They model how it will break up when traveling at these insane speeds and how the metal masses will melt and burn up during re-entry. They actually test this stuff in blast furnaces. It's a statistical model so it's theoretically possible a few small bits could make it to the ground on rare occasion, so we can't say debris will never happen - but there's been a lot of history and testing and the experts are confident it's extremely safe. The case of the MIR space station was very different than a Starship. MIR was built a long time ago by the Soviet Union and they used a big, heavily shielded power plant. That lead shielding was really the part that had a significant risk of not burning up fully on re-entry. Starship, Starlink satellites and other modern spacecraft are now usually designed to burn up on reentry. However, there are still some things in orbit and things we'll need to put in orbit in the future that won't entirely burn up on reentry. There will always be a very small risk of an accidental uncontrolled reentry causing a threat. However, these risks are vanishingly small both because we design these spacecraft with redundant systems and fail-safes and because Earth is mostly uninhabited oceans, much of our landmasses are unpopulated or sparely populated, even in the unlikely event one of the few spacecraft with a large mass that won't entirely burn up has failed and is de-orbiting out of control, we can still blow it up - and timing that at the right moment will still put it down in a safe place (like it did with MIR). There's no such thing as absolute 100% perfect safety. But you're far, far more likely to die from a great white shark attack than be injured by satellite debris. More to the point, a huge number of meteorites hit Earth every year and it's estimated over 17,000 survive to hit the surface. There are a bunch listed right now on eBay. Do you know anyone injured by any of the 17,000 space rocks that crashed into our planet this year or any airliners hit by one?

eps 2y ago

Apparently quite a bit of debris made it to the ground - > The locals here are pissed in Turks and Cacos. Huge dabris rained down everywhere It's from the pilot at the reddit link above. https://old.reddit.com/r/aviation/comments/1i34dki/starship_blew_up_in_front_of_us_had_to_divert/m7kgdvm/?context=3 https://old.reddit.com/r/aviation/comments/1i34dki/starship_...

ricardobeat 2y ago
No pictures or reports of anything falling in the Caribbean. People just love adding to the drama, they will later backtrack and explain that by “rain down” they meant the light show. It would be extremely unlikely due to the laws of physics, last time I checked they were still in effect.