More space news!

[tkdguy]

Is there a risk of war in space?

[Lawnmower Boy]

Is there a risk of war in space?

"n other cases, however, space-based warfare will not be so subtle. One of the most widely discussed celestial weapons systems is known as the “rod from God.” This is a non-explosive tungsten cylinder launched downward from orbit and capable of obtaining speeds of up to Mach 10 as it descends."

 

Seriously? This makes it into The Atlantic?

[Christopher]

"n other cases, however, space-based warfare will not be so subtle. One of the most widely discussed celestial weapons systems is known as the “rod from God.” This is a non-explosive tungsten cylinder launched downward from orbit and capable of obtaining speeds of up to Mach 10 as it descends."

 

Seriously? This makes it into The Atlantic?

The physics behind a Kinetic bombardment is as solid as the impacting rod, just not quite as fast and destructive.

Or do you mean the term "Rod From God"?

The English speaking world is known to call weapons "Peacemaker", so Rod from God is indeed a fitting name.

[DShomshak]

This month's issue of Discover magazine has an astronomy section called "Out There." It features articles on the Hubble Deep Field Survey, Thorne-Zytkow Objects (a red supergiant with a neutron star in its core -- mentioned here before by Cancer), and a way to study supernovae that happened long ago by examining their light bouncing off dust clouds. This incidentally suggests that some Type Ia supernovae have asymmetrical explosions due to being caused by two white dwarf stars colliding, rather than hydrogen from a companion accreting onto a single white dwarf.

 

Dean Shomshak

[NuSoardGraphite]

Oxygen star

The lighter elements were mined by advanced ETs since their lower temperatures are within the heat tolerance of their ship hulls.

[NuSoardGraphite]

"n other cases, however, space-based warfare will not be so subtle. One of the most widely discussed celestial weapons systems is known as the “rod from God.” This is a non-explosive tungsten cylinder launched downward from orbit and capable of obtaining speeds of up to Mach 10 as it descends."

 

Seriously? This makes it into The Atlantic?

The weaponization of space is a hot topic right now, especially since DARPA announced they fully intend to build weaponized space stations "just in case"

 

http://www.idigitaltimes.com/darpa-plans-build-us-military-space-base-stave-intergalactic-threats-542022

[Lawnmower Boy]

I'm not arguing that the weaponisation of space isn't an important and ongoing problem. I'm arguing that pre-orbited "kinetic strike weapons" are a dumb idea.

 

I mean, just beyond stupid. 

 

This artificial meteorite concept is often nicknamed ‘the rods from God’ even by its supporters, who usually claim it would be relatively cheap to set up (indeed some claim it already exists). They give the impression that at the press of a button, these rods will just fall from the sky on their victims. However it is not that easy. As each rod circles the Earth it is moving at least 7 km/s, to make the rod fall from orbit under gravity, we need to adjust its orbit to intersect the Earth’s surface. To do this each rod therefore needs to be attached to a rocket motor and its fuel tanks (or solid propellant), suddenly each cheap 100kg rod has ballooned into a multi-tonne vehicle, perhaps the size of a Soyuz spacecraft. At least it does not need a heatshield, a tungsten projectile could reasonably be expected to survive the expected heat of re-entry.

The ground-penetrating effects of such projectiles is grossly over-stated too- do falling meteorites of this sort of size always bury themselves hundreds of metres under the ground? Laboratory experiments show that objects striking the surface at speeds greater than 1 km/s are melted by their own kinetic energy before they penetrate the ground, effectively liquefying on impact. Rather than slamming into the target at 20 times the speed of sound, the rods may need to be slowed down to fast aircraft speeds to prevent them disintegrating on impact.

The problems of guiding each rod is usually dismissed with handwaving references to GPS, although some armchair space marshals also follow Pournelle’s fictional lead to suggest each rod would have its own imaging sensor to find and steer onto moving targets like tanks or warships. I have no doubt that the electronics are feasible but the rod now needs control surfaces hooked to its guidance system and sounds more like a missile than a cheap metal rod. Do these now complex projectiles require maintenance in orbit?

Finally, it is said that the rods can hit any target on Earth minutes after the KILL button is pressed. Once again, this doesn’t seem properly thought out. The rods can only hit targets on or near their orbital track, for weeks at a time some parts of the world would be invulnerable as their potential attackers would never come within hundreds of kilometers from their positions. The only way around this limitation is to have hundred of rods waiting ready in multiple orbits, requiring a ludicrous number of launches. Even if the target is directly under the rod’s orbital track, the attack may not be instantaneous, as those who order the attack wait perhaps 90 minutes for the rods to move around the Earth into position. Even the Joint Chiefs of Staff cannot overrule Sir Isaac Newton.

[Christopher]

I'm not arguing that the weaponisation of space isn't an important and ongoing problem. I'm arguing that pre-orbited "kinetic strike weapons" are a dumb idea.

 

I mean, just beyond stupid. 

 

This artificial meteorite concept is often nicknamed ‘the rods from God’ even by its supporters, who usually claim it would be relatively cheap to set up (indeed some claim it already exists). They give the impression that at the press of a button, these rods will just fall from the sky on their victims. However it is not that easy. As each rod circles the Earth it is moving at least 7 km/s, to make the rod fall from orbit under gravity, we need to adjust its orbit to intersect the Earth’s surface. To do this each rod therefore needs to be attached to a rocket motor and its fuel tanks (or solid propellant), suddenly each cheap 100kg rod has ballooned into a multi-tonne vehicle, perhaps the size of a Soyuz spacecraft. At least it does not need a heatshield, a tungsten projectile could reasonably be expected to survive the expected heat of re-entry.

The ground-penetrating effects of such projectiles is grossly over-stated too- do falling meteorites of this sort of size always bury themselves hundreds of metres under the ground? Laboratory experiments show that objects striking the surface at speeds greater than 1 km/s are melted by their own kinetic energy before they penetrate the ground, effectively liquefying on impact. Rather than slamming into the target at 20 times the speed of sound, the rods may need to be slowed down to fast aircraft speeds to prevent them disintegrating on impact.

The problems of guiding each rod is usually dismissed with handwaving references to GPS, although some armchair space marshals also follow Pournelle’s fictional lead to suggest each rod would have its own imaging sensor to find and steer onto moving targets like tanks or warships. I have no doubt that the electronics are feasible but the rod now needs control surfaces hooked to its guidance system and sounds more like a missile than a cheap metal rod. Do these now complex projectiles require maintenance in orbit?

Finally, it is said that the rods can hit any target on Earth minutes after the KILL button is pressed. Once again, this doesn’t seem properly thought out. The rods can only hit targets on or near their orbital track, for weeks at a time some parts of the world would be invulnerable as their potential attackers would never come within hundreds of kilometers from their positions. The only way around this limitation is to have hundred of rods waiting ready in multiple orbits, requiring a ludicrous number of launches. Even if the target is directly under the rod’s orbital track, the attack may not be instantaneous, as those who order the attack wait perhaps 90 minutes for the rods to move around the Earth into position. Even the Joint Chiefs of Staff cannot overrule Sir Isaac Newton.

If we asume a rocket engine, sure it becomes ineffective. What if we asume a railgun like design, however? That would mostly need power, not usually a hard to come by thing in space over time.

We known Tungsten is able to survive the speeds applied by a Railgun (Mach 5-10). And you would not need that much force either, as most of the impact power comes from Gravity.

 

About the issues of needing to be over the target and guinding this thing - no argument from me here.

Guiding something on re-entry is a lot harder then guinding it just through the air. But as a old proverb says: "Close counts in Darts, Horseshoes and Nuclear war". If you just make a big enough explosion, you hit your target. If anything the Radiation is a unwanted side effect of using Nuclear weapons - the primary purpose is the Kinetic force.

At the very least Kinetic Bombardment has the advantage over Nuclear weapons that you can quickly re-inhabit the area. Wich in turn makes using them a lot less problematic.

[tkdguy]

There may be an underground ocean on Pluto.

 

http://www.smithsonianmag.com/smart-news/new-evidence-strengthens-case-wet-ocean-beneath-plutos-surface-180959534/?no-ist

[Christopher]

There may be an underground ocean on Pluto.

 

http://www.smithsonianmag.com/smart-news/new-evidence-strengthens-case-wet-ocean-beneath-plutos-surface-180959534/?no-ist

Wow. If Pluto and Charon have those too, it would make 3 with Europa.

[Cancer]

There could also be one in Ganymede, but at greater depth, from what I recall seeing of theoertical structure models.

 

Also, some of the surface features seen in the old Voyager images of Triton are reminiscent of those on Europa, making for weak evidence of one there as well. The data set for Triton is very sparse, though.

 

Put a large mass dominated by water ice in orbit around a large planet, and I think it's hard to avoid a subsurface water region, assumibg any tidal heating at all.

[tkdguy]

Don't forget Enceladus also has a lot of water.

[L. Marcus]

But not a drop to drink.

[Cancer]

Don't forget Enceladus also has a lot of water.

The models I've seen, though, have substantially smaller volumes of it. It's just breaking through to the surface at this time.

[NuSoardGraphite]

Old.

[L. Marcus]

I'm not.

[Old Man]

Are so.

[tkdguy]

Russia planning its own space station away from ISS?

 

Organic molecule in space may be handy in explaining origin of life

[tkdguy]

Aurora spotted on Jupiter

[tkdguy]

Artificial gravity possible?

 

Perhaps, but the cost may not be worth it.

[Christopher]

Artificial gravity possible?

 

Perhaps, but the cost may not be worth it.

That is just normal centrifugal "pseudo gravity". A very old hat and prooven to work.

 

The Elysium model is plain oversized. And we do not need to go that big to do it.

Besides, usually low/0 gravity is why we want to go into space.

[tkdguy]

Celestial "fireworks"

[DShomshak]

This week's issue of the Economist has a pretty good article about the Juno mission to Jupiter. The Economist's science reporting often is surprisingly clear and accurate for a non-science publication.

 

Dean Shomshak

[tkdguy]

This week's issue of the Economist has a pretty good article about the Juno mission to Jupiter. The Economist's science reporting often is surprisingly clear and accurate for a non-science publication.

 

Dean Shomshak

 

Juno has arrived.

[DShomshak]

Juno has arrived.

<pops champagne>

 

Dean Shomshak