Skip to comments.Asteroid miners could use Earth’s atmosphere to catch space rocks
Posted on 08/29/2018 11:32:33 PM PDT by LibWhacker
Forget deflecting asteroids from hitting Earthsome engineers are drawing up a strategy to steer asteroids toward us, so our atmosphere can act as a giant catching mitt for resource-rich space rocks. What might sound like a crazy idea is actually quite business savvy, according to Minghu Tan, a Ph.D. student at the University of Glasgow in the United Kingdom who co-authored the new study. Thats because such near-Earth asteroids can host supplies, such as water and precious metals, that could support future human missions to space. But other scientists are skeptical that the concept will ever get off the ground.
The study involves aerobraking, or using the drag created by Earths atmosphere to slow down the path of an incoming object. Aerobraking isnt newevery incoming spacecraft to Earth uses it to slow itself down before landing, and probes to other planets, such as the European Space Agencys Venus Express and ExoMars missions, have also used the technique.
In the new paper, Tan and colleagues propose using aerobraking to slow small asteroids enough that they dont just shoot straight past Earth, but stay in orbit, where they could be mined for platinum or water. Those resources could then be taken to space stations to supply future missions or operations. Water, they write, could even be split into hydrogen and oxygen for fuel. All it would take is a precisely calculated push from an unmanned spacecraft, they report this month in Acta Astronautica.
And if the maneuver were done far enough from Earthmillions of kilometers, in most casesit likely wouldnt take much effort. Thats because a small push from far away would greatly change the angle of an incoming space rocks path. Tan notes that each case would be different, depending on the trajectory of the target asteroid, and says that modifications might be necessary if the asteroid gets off track.
I think its a grand gesture, says astronomer Sherry Fieber-Beyer, who was not involved in the study. But the director of the University of North Dakotas space studies observatory in Grand Forks adds that although its a neat idea, You can make anything look great on paper.
She says that although the trajectories of many near-Earth asteroids are relatively well known, their composition is not. Metal and other dense materials react differently than lighter rocks, making it critical to understand the makeup of any potential targets. If its made out of solid iron, you wont be able to slow that sucker down, Fieber-Beyer says. And what might appear at a distance to be an asteroid could actually be nothing more than packed rubble.
According to Feiber-Beyer and physicist Ingo Mueller-Wodarg, who studies planetary atmospheres at Imperial College London, another potential problem is that asteroids are not perfect spheres. An object with an odd shape could wobble unpredictably in orbit. The risk would lie in the asteroid having an irregular shape and hence experiencing torque, beginning to spin and hence go out of control, Mueller-Wodarg says. When we do aerobraking with satellites, we carefully fire small rockets to keep [them] on course and compensate for any such wobble.
But the biggest risk, Mueller-Wodarg and Fieber-Beyer say, would be causing an asteroid to crash into Earth, possibly causing widespread death and destruction. Tan disputes that charge, noting the paper looked only at asteroids smaller than 30 meters in diameter, which would vaporize as soon as they hit the lower atmosphere. He acknowledges that extra care would be needed if an asteroid were made of a denser material like iron, which might not burn up completely.
Tans team doesnt have any particular clients in mind, but he says that companies such as Deep Space Industries and Planetary Resources have plans to eventually capture and mine asteroids. Theyll have plenty to choose from, Tan saysmore than 1000 near-Earth asteroids fit his teams size requirements.
Of course, the idea of purposely steering anything larger into Earths orbit might have some detractorsjust ask the dinosaurs.
Some engineers? Well OK then; that's good. I mean if they're engineers, what could possibly go wrong!
if the diamond asteroid miners figure this out, I want in.
I am not at all worried about the military/terrorist applications of this technology. What are the chances that someone would and could sabotage the reentry system to created a (mach 25 plus) hard landing?
It’s called aerobraking, duh.
They want to collect water. On a planet that is 75% water.
What could they use the rocky material, once they have mined it?
Would it make great material for concrete or anything?
Sure but imagine the trucking fees to carry a load of rocks this far. Hell, the trucking for a load of gravel 30 miles is twice as much as the material.
Some people will risk looking like jerks just to get their names in print.
What could possibly go wrong? I mean like engineers and stuff.
Maybe they should ‘catch’ these rocks with the moon instead of the earth. A mishap would be a bit less fatal.
No you don't, bro. Do a little homework about diamonds. They are incredibly plentiful, even here on Earth. It is because DeBeers cornered the market and created an artificial scarcity that they are valuable.
The difference, though, is two-fold:
1) That water is not contaminated with salts, and
2) That water is already off the planet, so there is no requirement to expend incredible energy to get it out of the gravity well to get it to spacefaring humans.
Hank Johnson fears this could lead to earth tipping over.
It’s the cure for global warming.
Well, at least somebody is still reading Heinlein!
The Moon miner-colonists revolt against their collectivist masters on earth, using just such a system that was created for ore retrieval.
GMTA. Was about to post exactly the same idea. A rounding error on aero braking a big space rock could kill all humans and could actually be a all life on earth extinction event. Plus water plus sunlight = fuel you don’t have to lug up out of our gravity well.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.