An interesting note right at the end, so in case anyone missed it: this same launch is believed to be the source of 5 titanium "spaceballs" that fell onto New Zealand in 1972.
neither coincidence nor destiny alone -- your conscious life path, intermixed. How can you "know" this coincidence? How many circumstances on the edges of your lived life, are more influential than you recognize? What progress and events at larger scales that you are part of?
edit: It's obvious the quoted person had no idea what they were doing -- even a few seconds at arms' length from a fresh nuclear reactor core would be fatal. And quite a few satellites in that era were nuclear-powered.
It's not as if accurate knowledge of radiation was readily available, in the 1970's.
You're right, I didn't realize they fired quite that many (31?!) BES-5s into space and those are really the only non-experimental ones. Still, the chances of one of those falling out of orbit as a functioning reactor are about nil.
(By the way, there's an documented instance [0] mentioned in the sibling comments. The hazard is much worse than you'd think: the space reactor didn't simply fall in one piece, but left a trail of fragments 600 km long, some of which were lethally radioactive. It's pretty lucky this one happened in an uninhabited wasteland).
Yes but those dangers are the dangers of radioactive material - it's naturally 'hot', much of it also chemically toxic, etc. It's not core-at-criticality-that-murders-you-as-you-stand-next-to-it type of dangerous. I think that's still an essentially hypothetical danger of nuclear space junk.
As a general rule, it's not reactors functioning inside design parameters that are cause for concern, but rather failed reactors that have spew their guts and stopped working. Those are the reactors that will fuck you up.
They probably thought the dial paint would fluoresce brightly when exposed to radiation, like some florescent substances glow when exposed to UV. Would it work for alpha or gamma radiation? ¯\_(ツ)_/¯
Whatever the case, sure, it's certainly not a reliable safety test. But it was wise to keep this thing away from people. RTG's do have highly dangerous materials like polonium or strontium and there have been accidents.
Tritium is itself radioactive and used in watches to make a luminescent material glow. I think zinc sulphide was common and it would probably glow if lit up enough. Not sure you want to be near something that makes your watch dial markings glow visibly more than the radium or tritium that's in the paint, though.
The tritium interacts with a phosphor through beta decay, so presumably if you hung a watch near it the phosphor would glow brighter with higher concentration of beta decay. Basically a sort of visual Geiger counter.
Zinc sulphide, from brief googling, seems like it would glow in anything so if this was a thing, it probably makes most sense for gamma radiation since the 'detector' isn't being massively lit up by that internally already.
> The balls, which had Russian markings, were used to pressurise fuel tanks or as stabilisation jets, the report states.
Spent a bit of time in the metal trade, sometimes various metals that can best be described as oddities from Sheffield would be heading south, one such time some metal pieces were on this lorry no bigger than a chunk of cheese or hash brown thats broken off, clearly its been part of a larger plate of metal, but its magnetic strength was so strong it needed a screw driver to leverage it off anything it was stuck to. Never seen anything as strong magnetically since, but it had became a sort of competition with people/visitors asked to try to pull it off what other metal it was stuck to.
> 20 kilogram, titanium sphere,
> It is not something you would sell to a scrap dealer,'' he said.
The titanium being sold as scrap would come down in bars which had been angle-grinded all over to produce long metal splinters so that it could only be handled with a fork lift, the splinters would go through gloves if you tried to handle it. That shows to what lengths some scrap metals were "processed" in order to avoid being stolen.
Can anyone explain how it's possible for the apogee to reduce so much, while the perigee barely changes?
Wouldn't the air resistance that lowers the apogee also affect the perigee?
Or is it specifically because the object is being slowed at perigee, that the apogee lowers, while the perigee doesn't change much because the apogee is in vacuum?
Think of a very very elliptical orbit, one that's nearly a line and consider what happens when you take a bit of energy off the orbiting object. At perigee, when the energy is almost entirely kinetic, you're mostly just changing the velocity, rather than altitude of the object. At apogee, when the energy is almost entirely potential, it's the other way round - the change is almost entirely one of altitude. This is further stretched by the much more 'visible' effect of potential energy changes on altitude than of kinetic energy changes on velocity.
the atmospheric drag at perigee happens perpendicular to the object speed, which is tangential to the gravity field, so the object doesn't get shifts on it's vertical speed, only it's energy, having less to convert in potential energy (i.e. apogee height)
in the thereabout of perigee you have two arms, one inbound and one outbound. the horizontal component of the drag for both is all in the direction against the travel and slow the craft without changing the vertical component of its speed
the vertical component of the drag (for as long as the craft has the energy to get's outside of the dense atmosphere) kind of cancels out, as the drag force inbound pushes against your down velocity vector and the drag force outbound pushes against your up velocity vector.
there is however a small energy loss due to the fact that the journey trough the atmosphere isn't perfectly simmetrical, since you're losing speed along all the way, the inbound leg is shorter than the outbound leg, causing the vertical component of the drag going outside to slightly exceed the component of the vertical drag coming in - so your perigee does change little by litte due this (and other more nuanced effects, but we're painting with a large brush here) - this asymmetry gets stronger the more you stay in the atmosphere and the furthest you dip in the dense area, until you ultimately don't have the energy to escape anymore.
the fact that the atmosphere isn't on/off like that but has a long boundary layer stretching far from the dense parts kinda complicates things a little more, because drag is applied the whole circle, but not by that much.
The rule of thumb you can use to make this intuitive:
A change in velocity at a certain point x on an orbit will change the entire orbit, except that orbit will still continue to go through that one point x.
So slowing down at perigee will not alter the perigee. (It is actually the most delta-v efficient way to lower the apogee.)
If a chunk of Soviet space junk falls on someone's house, does the Russian Federation just shrug and say, "That was the USSR, bruh, sorry." They must have assumed responsibility for the Soviet space program, right? It's sort of like firing a bullet into the air... Doesn't matter how long it takes to come down, it's still your fault if it kills someone.
Kosmos 954 crashed in northern Canada with parts of the nuclear reactor still intact. The Soviets did eventually pay part of the bill Canada issued for the clean-up operation. It's the only claim so far made under the Space Liability Convention. [1] And yes, I believe the Russian Federation did inherit liability for orbiting Soviet space junk.
https://en.wikipedia.org/wiki/Outer_Space_Treaty says they inherited the USSR’s entry into the “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies”, which, among others, states states shall be liable for damage caused by their space objects, so they should fess up.
Depending on where it falls, in today’s political climate, they might say it’s part of a special military operation against nazis, though.
Given the number of people who celebrate with gunfire, it's indeed not terribly dangerous overall. Nevertheless, "it's still your fault if it kills someone."
"They found that while bullets traveling on a perfectly vertical trajectory tumble on the way down, creating turbulence that reduces terminal velocity below that which would kill, it was very difficult to fire a bullet in this near-ideal vertical trajectory. In practice, bullets were likely to remain spin-stabilized on a ballistic trajectory and fall at a potentially lethal terminal velocity."
So I'm not completely wrong. Of course, if you fire a bullet non-vertically, it's much more likely to have a lethal velocity when it returns.
My comment wasn't really one of correct or incorrect.
It was meant to highlight russellbeattie's propositional logic ("if it kills someone" then "it's still your fault"). I agree with you that it's "not terribly dangerous"[1]. Your comment seemed to have omitted the premise, so I wanted highlight how it was a non-empty set. [2]
[1] It's also not terribly dangerous to drive without a seat belt on either. I don't advise people do so.
[2] "Firing a bullet into the air" does not mean it must have time to slow to terminal velocity, nor is a bullet hitting a body the only way to kill. (See "Twenty-three people were electrocuted after celebratory gunfire brought down a power cable".)
Look, I agree with you - celebratory gunfire is pretty safe, and if you want to be safer, shoot straight up. Not only will it slow to zero, but you will be the one most likely to be hurt by it.
That said, just because you shoot straight up doesn't mean it will slow to zero.
russellbeattie is still right - the person who shot that plane is partially at blame for the damage to the plane and the injuries of the two people onboard.
(I say partially because from what I gather, neither person was a trained pilot and were joyriding.)
Mythbusters found pretty much the same thing - IF (big IF there) you can fire it EXACTLY vertically so that the returning bullet is just like it was dropped from a balloon or something, the terminal velocity is not lethal
However, with any significant angle off-vertical, the bullet still travels in a stable trajectory and orientation, so will impact with a speed much higher than random-orientation terminal velocity, and be potentially lethal, even if passing through some roofing material on the way into your body.
So yeah, don't shoot into the air, and don't be around where anyone does...
Depending on how it's modeled, 2024 to 2027 (with earlier being higher likelihood), or 2023 to 2025. No way to predict location but it'll be somewhere between 52°N and 52°S.
Napkin math: earth's surface area is ~510 million square kilometers. The lander is described as fitting in a 1-meter protective shell. So we have a roughly 1 in 510 billion chance of standing in the lucky spot.
(This of course would only be accurate if all square meters of the earth's surface were equally likely to be hit. Not the case since the lander appears to be orbiting the equator.)
The distribution of people is not uniform over the potential impact area, which is, as you mention yourself, not the whole surface of the earth. The error bars on this are too huge even by napkin standards, for this to work as an estimate.
That's assuming it comes straight down. Given that most people are somewhere around one to two metres tall, if it came in at a shallow angle it could ruin hundreds of people's day.
I think the shallow angle is unlikely since all horizont speed is not going to be compensated by anything, once it's gone by air friction, it's gone. Whereas vertical speed is helped by gravity. It of course depends on the initial velocity, but I doubt it's high enough for it to be an issue.
„The reentry of the Kosmos 482 Descent Craft will not be your standard reentry. The Descent Craft was designed to survive entry through the dense atmosphere of Venus. It will therefore likely survive reentry into the Earth’s atmosphere intact and make a crash landing (it is extremely unlikely that the parachute system will still work after more than 50 years in space). This will therefore be a high-interest reentry.“
If you shoot at something that is falling... it's still gonna fall, even if you hit it, brrak it up, etc. Whatever matter is there before will still be there after the hit, but on a less predictable trajectory.
If you break it up into pieces before it re-enters the atmosphere, you may get a higher proportion of burnup, because small chunks means lower overall ballestic coefficient per mass... But hitting stuff in orbit is difficult, and we would have a very hard time predicting the results.
The movie came out 15 years later and I doubt anyone remembered or knew about titanium balls falling on New Zealand. Spaceballs was always meant to be a direct parody of Star Wars.
I remember from that time people were more freaked out about Skylab falling down to earth--there were novelty t-shirts with a big target and "Skylab target" printed on them, all the late night TV hosts joked about it, etc. Skylab falling back to earth was a big event: https://www.youtube.com/watch?v=zoVXuKQ__0s
A water splashdown is the highest probability. But I think even with the 52 degree envelope, Russia is still probably the largest landmass in that envelope? So I take ironic pleasure knowing it’s more likely to smack back into Russia than any other country.
(I’m making an educated assumption about the geography, but could be wrong)
When the Soviet Union wanted to launch something to space, it did it as close to the equator as possible. That way you get the most boost from the spinning earth. (If you're not using a polar orbit.) So they used a southern point of Soviet union in Tyuratam in Kazakhstan, better known as Baikonur.
While the odds are low of any space debris hitting land, it was the photo in this article that surprised me - I was thinking billiard ball size debris, not this - http://www.stuff.co.nz/the-press/4542804/Government-report-o...