The thread for space cadets!

[Thorgalaeg]

If Psyche's the core of a larger body, how big was the parent? My rough guess is a bit smaller than our Moon.

Well, it is probably only a fragment of the core, i guess a planet is not like a LEGO and dont get dismounted in parts when destroyed, but more like a bunch of clay, whose composition changes more or less gradually with depth (with some fairly hard discontinuities as apparently has been detected inside Earth by geologists).

Anyway even if it was smaller than our moon the amount of valuable metals contained in its nucleus should be unimaginable for microbes like us.

 

[Samson]

XKCD explains the size of the black hole:

 

[hobbsyoyo]

Asteroid mining was toted, in the mid 10s, as being a huge gold mine waiting to be plucked. Luxembourg "looked" into it and some companies popped up which all went quiet.

I, for one, am very suspicious of the notion that Asteroids are just money bags waiting to be picked up*. I can readily see their use as providing the basics for a interplanetary society, especially C class roids or S class; but M classes just seem too good to be true. Of course, if the science holds up, the math holds up, and the results hold up, I won't turn against the results. It would be a good boon. It just seems hyped up, is all. All the objects in the Asteroid Belt and Oort Cloud are less, combined, than the Moon, right? The Kupier Belt has a bit more, but still not by much, right? though that by itself does not preclude absolute wealth garnered from the planetsmals floating about....

I know that Mining the Sky: Untold Riches From The Asteroids, Comets, And Planets by John S Lewis looked into it, Zubrin doesn't talk about it much IIRC.

*Yes, I know Asteroid Mining is more complex than that.

Luxembourg did more than just look into them - the country created it's own space investment office and invested in one of them in addition to some other start ups. They lost money on the deal and the mining company was recently sold to a blockchain company for reasons no one understands.

There are a lot of technological challenges that have to be solved with asteroid mining before it becomes a reality but one issue it does not have is lack of valuable targets. Even if all the asteroids do have less mass than the moon - that's still an enormous amount of material and if you can physically get to the asteroids, the material should be fairly easy to dig up and process as you are not fighting gravity and complex geology.

I have that asteroid mining book, it's pretty good. Also, I would not put a ton of stock in what Zubrin says on anything other than getting to Mars. His biases are so extreme and his personality so acerbic that not that many people take him seriously, for good reason. I really want to like him and I have read his books on exploration but he's got a habit of going after sound ideas that don't align perfectly with his own personal goals.

-------------------------


Boeing has announced a delay to their first Starliner flight and it looks now as if SpaceX will be flying astronauts before Boeing even mounts a test launch. And of course Boeing will be asking for more money at every step of the way.

Oh and a recently-launch Boeing satellite has sprung a leak and is drifting through the geostationary arc, kicking off debris as it goes. This is the second failure of the same type of satellite in the last year or so.

That company is on a real losing streak.


------------------------

Falcon Heavy launches tonight!

 

[Imaus]

Regarding Psyche, NASA's Psyche mission is underway, so that'll be interesting. Slated for the 20s.

In today's news:

Israel's civilian lander has been lost.

All Falcon Heavy boosters have returned to Earth.

NASA releases the full study of their twins; judges human health in space for a year or more to be acceptable.

 

[Ajidica]

So, I guess the Jews aren't in space yet?

Israel's Beresheet spacecraft crashes on Moon
The first privately funded mission to the Moon has crashed on the lunar surface after the apparent failure of its main engine.

The Israeli spacecraft - called Beresheet - attempted a soft landing, but suffered technical problems on its descent to the Moon's surface.

The aim of the mission was to take pictures and conduct experiments.

Israel hoped to become the fourth country to land a spacecraft on the Moon.

Only government space agencies from the former Soviet Union, the US and China have made successful Moon landings.

https://www.bbc.com/news/science-environment-47879538

 

[Berzerker]

XKCD explains the size of the black hole:

damn, my math is still way off. I better give it up. Neptune's mean orbit is about 3 b miles, not 45 b km, and Pluto's mean is about 5.8 b km

 

[Broken_Erika]

Israel's Beresheet spacecraft crashes on Moon
The first privately funded mission to the Moon has crashed on the lunar surface after the apparent failure of its main engine.

The Israeli spacecraft - called Beresheet - attempted a soft landing, but suffered technical problems on its descent to the Moon's surface.

The aim of the mission was to take pictures and conduct experiments.

Israel hoped to become the fourth country to land a spacecraft on the Moon.

Only government space agencies from the former Soviet Union, the US and China have made successful Moon landings.

"We didn't make it, but we definitely tried," said project originator and major backer Morris Kahn.

"I think that the achievement of getting to where we got is really tremendous, I think we can be proud," he said.

Prime Minister Benjamin Netanyahu, watching from the control room near Tel Aviv, said: "If at first you don't succeed, you try again."

After a seven-week journey to the Moon, the unmanned spacecraft approached a final orbit at 15km (9m) from the surface.

Tensions were high in the command centre as communications were lost before Opher Doron, the general manager of Israel Aerospace Indurstries' space division, announced there had been a failure in the spacecraft.

"We unfortunately have not managed to land successfully," he said.

https://www.bbc.com/news/science-environment-47879538

 

[hobbsyoyo]

I wonder if the Beresheet ran out of fuel or pressurant to push the fuel into the engine. Helium is a typical pressurant and it's not easy to store, I would not be surprised if that ran dry. I read they attempted to reset the lander when the engine cut out but they couldn't restart it.

 

[Berzerker]

oh noes, Willzyx

 

[hobbsyoyo]

oh noes, Willzyx

?
I don't follow

 

[Berzerker]

South Park episode where the Seaworld guys running the Orca show fooled Stan or Kyle into thinking the whale could talk and was from the Moon. So the boys steal it and pay the Mexican space agency to take it back. The show ends with an image of a dead Orca lying on the surface.

 

[Broken_Erika]

Ci fly!

 

[r16]

The name is Psyche 16. Estimated value 500+ quintillions of dollars in nickel, iron and precious metals such as gold, about 100 billions dollars for every living person.

thanks for the info . Sillywise , this is obviously the reason why a company more famous in the 80s for construction was declared to have an interest in space mining yesterday , in the glorious pages of the former pinnacle of yellow journalism in the country . Seems close enough a name right ?

 

[Bootstoots]

The key is that, thank to Archimedes, light elements float to the surface and heavy elements sunk to the center of the liquid hot magma ball a young forming planet basically is, so all valuable metals tend to concentrate in the nucleus. We have only access to Earth crust which is all light elements and very poor in heavy elements, and the few traces there are hard to find and hard to extract. However, if a planet or planetoid has been cracked into a billion of bits by some cosmical force we can have access to the bits corresponding to the nucleus, such as Psyche 16, which are like 100% heavy elements.

I'll chime in to add a little bit.

It's not quite true that all heavy elements have a tendency to sink to the core. The four naturally-occurring* elements with the highest atomic numbers are lead, bismuth, thorium, and uranium, and all four are relatively common on the surface. The elements that are rare in Earth's crust are the ones that are nonreactive as well as dense. Anything that readily reacts with oxygen or sulfur, in particular, will end up forming bonds to those elements and become concentrated disproportionately in the crust. The rarest stable elements in the crust are the non-reactive or "noble" metals, including gold and the platinum group (platinum, palladium, osmium, iridium, ruthenium, rhodium).

Most asteroids are small enough that they have not differentiated significantly, so they'd have the same concentration of noble metals on their surfaces as in their cores. Even a smallish metal-rich asteroid can easily have more noble metals than we mine today: global platinum production, for instance, is less than 200 tons/yr, and production of iridium/osmium/rhodium is far smaller still. This is all despite the fact that platinum, palladium, and rhodium are all in high demand as catalysts, in catalytic converters and a bunch of industrial chemical processes. So there is quite a bit of upside to asteroid mining, it's just that the technical demands are extremely challenging and it's unlikely to be commercially viable any time soon.

Incidentally, one of the strongest pieces of evidence for the asteroid impact that caused the K-T extinction event 66 million years ago is the worldwide thin layer of iridium and platinum dating to that time.

*Excluding elements that are present only in traces as intermediate decay products, such as polonium, radium, etc. Only primordial nuclides are counted.

 

[Cutlass]

So, I guess the Jews aren't in space yet?


https://www.bbc.com/news/science-environment-47879538

Pigs got there first. Made space not kosher.

 

[Berzerker]

I'll chime in to add a little bit.

It's not quite true that all heavy elements have a tendency to sink to the core. The four naturally-occurring* elements with the highest atomic numbers are lead, bismuth, thorium, and uranium, and all four are relatively common on the surface. The elements that are rare in Earth's crust are the ones that are nonreactive as well as dense. Anything that readily reacts with oxygen or sulfur, in particular, will end up forming bonds to those elements and become concentrated disproportionately in the crust. The rarest stable elements in the crust are the non-reactive or "noble" metals, including gold and the platinum group (platinum, palladium, osmium, iridium, ruthenium, rhodium).

Most asteroids are small enough that they have not differentiated significantly, so they'd have the same concentration of noble metals on their surfaces as in their cores. Even a smallish metal-rich asteroid can easily have more noble metals than we mine today: global platinum production, for instance, is less than 200 tons/yr, and production of iridium/osmium/rhodium is far smaller still. This is all despite the fact that platinum, palladium, and rhodium are all in high demand as catalysts, in catalytic converters and a bunch of industrial chemical processes. So there is quite a bit of upside to asteroid mining, it's just that the technical demands are extremely challenging and it's unlikely to be commercially viable any time soon.

Incidentally, one of the strongest pieces of evidence for the asteroid impact that caused the K-T extinction event 66 million years ago is the worldwide thin layer of iridium and platinum dating to that time.

*Excluding elements that are present only in traces as intermediate decay products, such as polonium, radium, etc. Only primordial nuclides are counted.

and just to confuse the picture the Earth suffered thru the late heavy bombardment about 4 billions years ago when several large objects impacted the Earth and may be responsible for the heavy stuff we find in the crust.

 

[Berzerker]

new study suggests life began on land by concentrating nitrogen in shallow pools

not really cosmic, but still of interest

https://phys.org/news/2019-04-earliest-life-arisen-ponds-oceans.html

 

[Thorgalaeg]

https://eventhorizontelescope.org



I wonder, could a virtual telescope the size of the solar system be made placing a constellation of linked satelital telescopes orbiting the sun at trans-neptunian distances? We should be able to count the scales of the aliens living on exoplanets with such thing.

 

[hobbsyoyo]

https://eventhorizontelescope.org



I wonder, could a virtual telescope the size of the solar system be made placing a constellation of linked satelital telescopes orbiting the sun at trans-neptunian distances? We should be able to count the scales of the aliens living on exoplanets with such thing.

It is possible to do but the resolution is going to be on the order of being able to see continents.

Such a constellation would take about 20-50 years to put up, including 5-15 years of transit time for each.

Away from the Earth's magnetic field, the satellites will need on-board propulsion to manage the momentum of their reaction wheels. The reaction wheels allow the satellite to point at spots in space but eventually they are spin up as fast as they can and you need some external force to unload that stored energy. Propulsion allows you to do this and you won't need much of it as the there won't be much disturbance torque from solar radiation pressure or planetary gravity for the reaction wheels to fight against. Still, having propulsion on board makes the satellite more complex, larger and more failure prone. They would also need hefty RTGs to power beefy radios to talk to the Earth and of course they will have to launched with a ton of energy to get out that deep into space so they would each require something like the Falcon Heavy or SLS.

 

[hobbsyoyo]

@hobbsyoyo never heard of reaction wheels before but could you use the stored energy in the wheels as a source of energy and so lower its spin.

You can't actually, unless you have on board propulsion and even then it's a losing proposition. When you spin up the wheel, it will cause the bus to spin by applying a torque to the bus. You can stop this bus spin with propulsion. To extract the energy back out of the flywheel, you could slow down the wheels with electromagnetic braking but again this would impart a spinning torque to the bus that you would have to use propulsion to offset.

In between spin up/spin down, the wheel would tend to hold the bus in a stable pointing attitude but this scheme doesn't work because the cost of bringing the extra fuel mass more than offsets the power gain (really not a gain, trading rotational kinetic energy for released chemical energy) and adds mass. Also, for the wheels to be big enough to hold the bus stable purely on their own momentum, they have to be very heavy, further adding cost and mass - and the larger your mass, the more propulsion you need an so on.

A reaction wheel is a type of flywheel where you spin a mass to impart a torque on the bus, allowing it to change pointing attitude without expending propellant. But they can only spin so fast before they fail, which means there are limits to how much pointing you can do.