Scientist proposes aerobraking asteroids into Earth orbit
What could possibly go wrong? A scientist has proposed the use of the Earth’s atmosphere to aerobrake resource-rich asteroids into Earth orbit to make them easily available for mining.
In the new paper, Tan and colleagues propose using aerobraking to slow small asteroids enough that they don’t 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 Earth—millions of kilometers, in most cases—it likely wouldn’t take much effort. That’s because a small push from far away would greatly change the angle of an incoming space rock’s 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.
They propose doing this only with small asteroids, less than 100 feet in diameter.
I am sure my readers can outline the numerous problems with this proposal. From my perspective, the primary one is that it is almost impossible to predict the precise path of these kinds of asteroids. Their rotation and irregular shape combined with radiation pressure from the Sun tends to make their solar orbits somewhat chaotic and difficult to predict at the accuracy needed to safely nudge them into a close fly-by of the Earth.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
What could possibly go wrong? A scientist has proposed the use of the Earth’s atmosphere to aerobrake resource-rich asteroids into Earth orbit to make them easily available for mining.
In the new paper, Tan and colleagues propose using aerobraking to slow small asteroids enough that they don’t 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 Earth—millions of kilometers, in most cases—it likely wouldn’t take much effort. That’s because a small push from far away would greatly change the angle of an incoming space rock’s 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.
They propose doing this only with small asteroids, less than 100 feet in diameter.
I am sure my readers can outline the numerous problems with this proposal. From my perspective, the primary one is that it is almost impossible to predict the precise path of these kinds of asteroids. Their rotation and irregular shape combined with radiation pressure from the Sun tends to make their solar orbits somewhat chaotic and difficult to predict at the accuracy needed to safely nudge them into a close fly-by of the Earth.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
It’s not so hard. They could get a good grip of its properties by putting a thing in its orbit and measuring its movements. Like Osiris and Hayabusa are dong right now.
Aerobraking is a big thing! But it doesn’t help the Moon or Mercury. Or Europa. Giving Earth a new moon would be a great accomplishment. Grass, and cows chewing grass lazily, would never have achieved that.
Let’s start with one mistake creating a small catastrophe…
and Aerobraking, as Robert suggested, is normally done with objects with regular shapes designed to do it, you’d lose any volatiles in the process, which means your hopes of mining water would essentially be gone.
Add to the issues the economic issues of getting an unmanned craft out to the asteroid to being the process, and you have something that’s far from economically feasible.
As long as ground zero is the DNC HQ , or where ever the queen of the swamp HRC hangs her hat , I’m down with it !
In the late 70’s I read several books dealing with asteroid mining, mostly as a way to build orbital solar power stations. The general idea was to place the rocks at the L4/L5 Lagrange points in the Earth -Moon system. Although most simulators (https://www.purdue.edu/impactearth) predict that an object <30 meters diameter would break up in the atmosphere, I can't imagine people would be thrilled about having asteroids thrown at Earth. Glass houses and all.
Large astroids are skipping off our atmosphere and are tracked daily.
Big ones that enter our atmosphere, like the one in Russia that blew out windows and stoped cell phones from working, are not uncommon showing the severe risk.
Only astroids in close proximity are moving slow enough for this maneuver to work. (that’s assuming it’s irregular shape, irregular weight distribution, and loose soil material doesn’t upset trajectory, or out right explode due to uneven heating)
Astroids from the belt, for example, would have too much momentum. It would need a series of Aerobraking through a thicker atmosphere like Venus before it can be captured by the earth. Many years of planning, not very Cost-effective. Too many variables that can go wrong.
If it hits the moon, it will cause the earth to have rings like Saturn making space travel very difficult not to mention satellite failures.
If it hits the Pacific, on the other hand, it would solve the problem of getting water into space…
what could possibly go wrong?
pivoting…
Armageddon [1998]
Karl is The Man!
-adult language alert-
https://youtu.be/eLuvwrHacYk
1:07
Since we will more than likely not have or want a totally robotic crew and machine for the mining mission why not just send a larger ship and actually pre process the asteroid way out there instead of in Earth orbit.
Separate the water out and store it for use later. At the same time crush and separate the rock.
Find a way to use the crushed rock as reaction mass. This would save the water for better uses.
Everything stored in insulated bags outside the main ship. After the ‘roid’ is totally processed the crew can return in a smaller part of the ship on a fast return path and the main bulk ship can then take years to return.
Bring it in as slow and safe as needed.
@pzatchok:
I think the reason there haven’t been more proposals for processing in the Belt is energy density. Unless you’re going to haul large reactors (expensive) out there, you’ll be using solar power, and it may well be that the solar flux density between Mars and Jupiter is insufficient to power industrial processes economically. And it may be better to have processes of higher complexity closer to Earth. We can do this.
Take the huge reactor.
We absolutely must have a way to use a standard nuclear reactor in space. We must have that amount of power available if we are going to do anything more than futz around playing at working.
pzatchok, Blair;
I agree with both of you. Modern means of processing ore efficiently require gravity, caustic chemicals, pressurized containers, and a large source of power.
Such a large industries would take place one step at a time. First, a “human occupied base” must be established to construct the foundry for the manufacturing of the mining equipment, too heavy to lift into orbit from Earth, to mine the mineral rich moon to build the ice mining ships in low gravity lunar orbit.
Ice mining will be priority because rocket fuel will be the lifeblood of the solar system.
The other priority is high density power/heat.
Thermo nuclear reactions provide both.
Current nuclear submarines technology of a closed system methods can easily be adapted to space. (modern solar panels have nearly 30 years half-life, much less if exposed to a solar storm)( astroid belt is 2 to 4 AU astronomical units away from the sun having 1/4 to 1/16 the amount of light we have on earth. Not to mention all that gravel flying around)
Once the Chinese miners send the finished manufactured parts to low lunar orbit, engineers at the USA Space station will assemble the huge chemical manufacturing plant that will be sent to an ice rich astroid/Moon (like Europa) for the purpose of providing continuous supply of finished product of rocket propellant.
At the same time a robotic fleet of astroid metal detectors will search out rare elements, that the moon cannot provide, surveying potential targets/tagging claims. If abundant resources are found, huge rotating ships, that will never return to earth, will be available by then that will not only mine the metals, but be the manufacturing center of parts and all necessities in one big slow moving modular city ship. (It would be a waste of resources to send raw materials back to the moon for processing just to be sending all of it back out to the outer rim)
At first the crew will sign on for five or 10 year working contracts that will allow them to return to earth “rich”. As metal and glass housing and storage units are created from processing waste, the city will grow larger, children will be born in space that will not wish to return to a home they never knew. In this way, another new colony is born. The Jovian moons, Europa, Vega will be their home worlds.
If Russia has acquired 20% of the US stock pile of uranium, they will be a part of this future. (unless fissionable materials can be found or created out there)
Most of the asteroids will have nuclear ion thrusters like Pzatchok’s suggestion for reaction mass to maneuver the rocks closer to the city. Once sufficient course correction has been obtained, the thruster will move to a new astroid.
Eventually all long distance travel by chemical Rockets will have mylar balloon like recapture systems, miles in size, to preserve the used chemicals for reprocessing back into fuel again. A heated rod or thrust bell will cause the water vapor to sublimate to the cold skin of the mylar to freeze. Slowly rotating the Mylar in sunlight will force the water to collect in the coldest place making it easy to retrieve.
In theory, you can permanently reprocess your thrust fuel. But it takes more power to separate and compress the hydrogen and oxygen than the thrust energy that is eventually used. Hydrogen is hard to store without substantial losses so this method is best used on a continuous basis which means you will still need a nuclear reactor to provide continuous power while the re-processed rocket fuel provides substantial 1G thrust.
In this way, Uranus, Neptune, Pluto become accessible with limited resources.
I’m just a dreamer…
There are advantages to moving an asteroid to Earth orbit for mining. For instance, virtually all asteroids change in distance from the Earth as they orbit the sun, complicating the transport of the mined material — which may want to use aerobraking for capture into Earth orbit (aerocapture).
As the city of Chelyabinsk, Russia, discovered five years ago, a 20-meter asteroid can wreak havoc, so if aerocapture were to be used to bring an asteroid (or even the mined material) into orbit, then it might be best to time the maneuver to take place far from any populated areas. Over the Pacific Ocean would be a good choice. As Robert suggested, there may have to be some midcourse corrections and final approach guidance in order to assure a safe aerocapture maneuver.*
commodude noted that an asteroid has an irregular shape and that volatiles would be lost in the process. The final orbital trajectory may be difficult to calculate, due to the shape’s hard to predict interaction with the atmosphere, but the savings in propellant may make the maneuver cost effective despite a need to do additional maneuvers after the Earth orbit capture. The volatiles lost would likely be mostly from the surface, where they would be easiest to harvest, but any volitiles beneath the surface may remain cool enough to stay with the asteroid. People who have had meteorites crash through their roofs have noted that the remaining rock was surprisingly cool, because the rock was very cold in space and the heat generated during entry through the atmosphere did not penetrate deep enough into the rock to make it hot throughout.
Solar power stations in geostationary orbit are still thought to be a feasible energy source, and using materials already in space might make them affordable.
* Please note that these calculations work only in the case of spherical asteroids in a vacuum. (If you didn’t get a chuckle: https://en.wikipedia.org/wiki/Spherical_cow )