The thread for space cadets!

[uppi]

Not really, they are going to be going only maybe a fraction of orbital velocity and even chunks of debris that pick up sufficient velocity from the impact likely will not be angled in such a way as to achieve a stable orbit. At best you'd wind up with some debris with some apogees high up but with perigees inside the atmosphere or even lower. I imagine most debris would actually lose most velocity overall as they missiles would be coming at each other close to head-on.

The head-on collision only means that the mean velocity over all debris pieces will be small. The individual pieces will still have high speed, because the kinetic energy before the impact needs to go somewhere. A perfect head-on collision would probably be most likely to spew out debris into all angles, including those which could enable stable orbit. But, yeah, the need to match angle and speed would result in a very small chance of orbital insertion

For reference, early generation, nuclear-tipped anti-ballistic missiles topped out at around Mach 8-10 which is less than half of what is needed for orbit. I would expect new-generation interceptors to travel significantly slower as they actually have to line up direct impacts (so can't be going as fast as they need time to maneuver) and there are much better radar systems meant to track incoming warheads which give the missiles a longer interception window which means they don't have to accelerate to such crazy speeds. And those old Mach 8+ interceptors were designed around dealing with the heat load of extremely high-speed in-atmosphere flight in a way that is not reflected in current designs although of course there could be stuff the general public can't see but it's kind of doubtful.

I have not studied this extensively though so I could be wrong.

It may be true that the collision speed is not high enough, but that line of argument means "at unprecedented altitudes and speeds" does matter.

 

[r16]

oh , ı even have a question today !

m pathetic life gets influenced so many stuff and stuff . Back of calender page , some guy due West of my town and a place my family once went to seaside for a summer holiday turns out to have a research firm and this firm creates "Amorfosbor" , a rocket fuel America is marketing for the last 50 years at 4.5 million dollars per metric ton . ı expect such a thing to really to exist ? Yeah , the question is the last sentence ...


now that this otherwise unnamed guy is a Nobel candidate for that !

Spoiler :

must be a Western plot to that he didn't get it , too . For making bor/boron exports (worth otherwise 50 000 dollars a ton) far more valuable . Because all those traitors betrayed the country and America treats New Turkey badly and them New Turkey people develop such stuff . Which encourages friends and scares enemies . Over the weekend the laughter was about my sets of skills , which are even unique . The political situation much the same , we hear tons and tons of stuff of breaking the terror corridor , setting East of Euphrates aflame . Which all rest on back to 2014 and a little group of Iraqis who were killed in Telafer , at the very beginning of the wondrous ISIL . Whose exemplary conduct led "a secular" threat to Iranian assimilation of Iraqi Shia which forced them to act more vigorously , a process the Barack spineless jerk Obama could stop only with bribing Tahran with the deal and bringing Russians in to balance Iran and stopping TOW deliveries to beardies so that the Russians could dare setting foot in Syria or like that . Which also created doubts between the Kurds and the ISIL , which came to a head in Sinjar , which resulted in 2015 elections where the seperatists betrayed A-K-P by following American orders to be closer to Turkish mainstream and making New Turkey loose elections . Telafer is why Syrian refugees are now facing the prospect of being deported and everybody loves the Turkish flag today . Instead of allowing Syrian jihadi leaders wipe their backsides , so that if they were men enough people would come to the spot to be beheaded and served as dinner . Telafer is why America allows New Turkey buy S-400 and begs New Turkey not to assemble them or America will be forced to use sanctions and New Turkey thinking it's New Turkey doing all that , threatens Boeing with not buying airliners if America does not let F-35 , because this would look like America punishing New Turkey and nobody can not ever do nothing to New Turkey ... Telafer is the blackhole of Western designs in the Middle East , Gertrude Bell advised it to be razed , while one of these advisers of Trump , Macmaster by the name , limited himself to have a thread locked , because he had also failed under Petraus to cleanse it of evil and create the pipeline route . Come on , if ı can't bombard them all Americans from the orbit , with my unique skills , ı could at least give them some Telafer instead of Hell ?

also in the news , like because they have discovered it now , one single newspaper carries the pictures of Kelly McGillis , the same exact shots that were all over the web when the shooting began .

 

[Samson]

Our best chance to see alien life yet?

GJ 357 d is a planet only 31 light years away, orbiting an M-type dwarf about one-third the Sun’s mass and size and about 40% cooler. It orbits the star every 55.7 days at a range about 20% of Earth’s distance from the Sun. This is pretty close, meaning that if it has an atmosphere we may be able to detect it, and possibly oxygen and / or methane which would be signs of life (and if found together, quite good evidence for it).

NASA press release, primary literature.
So the surprising thing is from that picture, who knew that the real universe looked so much like Civ 4 Final Frontier.

 

[hobbsyoyo]

The Planetary Society is celebrating the successful orbit change of their satellite using solar sails.
https://spacenews.com/planetary-society-declares-solar-sailing-mission-a-success/

I personally think this technology is going to be a dead end of utility only in a few circumstances. As solar-electric propulsion continues to improve, the use cases where solar sails are superior will shrink to nothing. And if in-space refueling from propellants gathered from the outer space sources ever takes off, that will further reduce the utility of solar sails.

The Chinese are now testing grid fins on existing rockets to guide spent stages into smaller impact zones to spare the population from boosters dropping on their heads. They will also later use this technology to land boosters.
https://spacenews.com/chinese-long-march-launch-tests-grid-fins-for-safely-future-reusability/

 

[Thorgalaeg]

The Chinese are losing their essence.

 

[El_Machinae]

I understand why GJ 357 is being touted as being 'Earthlike'. It's a new mechanism by which we're detecting planets, and people want to see 'Earthlike' in the news headlines.

BUT, is there anything that makes the d planet more 'Earthlike' than many of the other closer planets touted as 'Earthlike'?

 

[hobbsyoyo]

The Chinese are losing their essence.

What do you mean?

I understand why GJ 357 is being touted as being 'Earthlike'. It's a new mechanism by which we're detecting planets, and people want to see 'Earthlike' in the news headlines.

BUT, is there anything that makes the d planet more 'Earthlike' than many of the other closer planets touted as 'Earthlike'?

I haven't looked into this one in particular but I would put money on 'almost nothing like Earth' except it's in a habitable zone and not a gas giant. But the truth doesn't make for good headlines...

 

[Thorgalaeg]

What do you mean?

Worrying about where the spent stages fall, that is so bourgeoisie...

 

[hobbsyoyo]

Worrying about where the spent stages fall, that is so bourgeoisie...

Haha don't worry, they're still dropping boosters in populated areas. They're just trying to aim them a bit better!

 

[hobbsyoyo]

Rocket Lab reversed years of saying they weren't going to reuse stages by announcing today they are going to do just that. They don't have the propellant margins to bring it down propulsively and instead are going to try air-capturing with a helicopter.

https://spacenews.com/rocket-lab-to-attempt-to-reuse-electron-first-stage/

 

[r16]

ı , about last week , saw this Al Crusading documentary about the 787 at the time it was grounded for the batteries . It was dangerous , it was murder , and the producers "confess" they are flying on 787s these days . Well , ı wouldn't expect them to say that the Sonic Cruiser could possibly be folding Money for a certain engine maker , so the "West" reached a consensus that it had to be 787 for which all the big three Anglosaxon engine makers could sell and oh my , even the A380 has gone down ... Well , it's only Arabs who think that they are great and equals of the White boys . How many 380s Qatar bought by the way ?

edit : a few it turns out , in addition to being the first buyers of A350 . Well , well ...

 

[r16]

yes , indeed but they are not debating my date with the Martian chick yet

as a reference that it won't be lost or something , also provides a point of rant against London , which saw an emergency landing due engine issues and that was followed on by some hacking that stopped 100 flights or so . Should one thank to Russo-Chino-Serbo alliance of hackers ?

 

[Samson]

Todays XKCD:

So how do they work that out? I guess they can calculate the amount of dark matter in the galaxy by "amount of matter needed to stop the outer systems flying off" - "amount of normal matter", but how do they know the distribution? It could be all in the middle, it could be distributed evenly, it could be similar to normal matter. How do we know about these dark matter squirrels?

 

[Lexicus]

So how do they work that out? I guess they can calculate the amount of dark matter in the galaxy by "amount of matter needed to stop the outer systems flying off" - "amount of normal matter", but how do they know the distribution? It could be all in the middle, it could be distributed evenly, it could be similar to normal matter. How do we know about these dark matter squirrels?

I'm guessing it's a large set of data on star orbits around the center. You can model how it would look given different mass distributions and then compare that to the actual real data.

 

[hobbsyoyo]

I'm guessing it's a large set of data on star orbits around the center. You can model how it would look given different mass distributions and then compare that to the actual real data.

Yeah I think they have evidence that galaxies and larger structures could not exist in the forms they take without a bunch of dark matter helping to hold them together. I just saw an article saying they found a bunch of missing galaxies which, if confirmed, would lower the amount of dark matter we think there is in the universe but I didn't read it past the headline.

 

[uppi]

Todays XKCD:

So how do they work that out? I guess they can calculate the amount of dark matter in the galaxy by "amount of matter needed to stop the outer systems flying off" - "amount of normal matter", but how do they know the distribution? It could be all in the middle, it could be distributed evenly, it could be similar to normal matter. How do we know about these dark matter squirrels?

Short answer: we don't.

I am pretty sure that density is just the amount of dark matter divided by the size of the galaxy. How dark matter is distributed over the galaxy is an open question. Of course, there are limits. It cannot be all concentrated in one spot, because then we would see the gravitational effects. From gravitational lensing, we can see that the dark matter distribution is not homogeneous, but there are concentrations of dark matter. The "one squirrel" is just a tool to illustrate the scale of dark matter and is just an average. It might be that there is no dark matter near Earth at all.

 

[Imaus]

So a rocket exploded in Northern Russia and there was a momentary rad spike. BBC is reporting 5 dead so far.

But what caused the spike? Were they trying out a NTR or something?



..

 

[red_elk]

Official explanation is "Explosion during maintenance of isotope power source on liquid-fuel engine".

 

[hobbsyoyo]

So a rocket exploded in Northern Russia and there was a momentary rad spike. BBC is reporting 5 dead so far.

But what caused the spike? Were they trying out a NTR or something?



..

Earlier this year they were talking about making a nuclear-powered rocket engine of some type for space exploration and (IIRC) also for an unlimited range cruise missile as well. I thought it was just hot air, as with many other Russian space initiatives, and it turns out I was right for the wrong reasons.

 

[hobbsyoyo]

Vector is shutting down operations and may be forced to close permanently. Their main investor backed out even though they just won their first USAF contract. I wonder if this is the start of the great culling of start-ups that is surely going to happen. I also wonder if the government will step in to support any of these companies if they do start folding en masse.

https://spacenews.com/vector-replaces-ceo-amid-reports-of-financial-problems/