Planetary Resources

[QuantumG]

The business plan:

1. Fly some telescopes.
2. Find some asteroids
3.
4. Profit!



probably involves NASA, somehow.

[jongoff]

The business plan:

1. Fly some telescopes.
2. Find some asteroids
3.
4. Profit!



probably involves NASA, somehow.

Actually, I think their real plan is more like:

1. Fly some telescopes.
2. Point them sometimes at earth and sometimes at asteroids.
3. Profit.
4. ...
5. ...
6. Find asteroids
7. ...
8. ...
9. Mine asteroids
10. ...
11. More profit

Or something like that.

~Jon

[RocketmanUS]

Latest Wall St article had them changing focus to mining asteroids for water to refuel satellites. Not sure how that is going to work, current satellites don't use water for fuel.

They could be looking at making propellants that current satellites use.

The water could be for possible future Bigelow stations.
Water for drinking, ect.
Waste water processed for O2 ( breathing ) and L2 to make methane with CO2 from crew exhale.
Methane and O2 for RCS. If more carbon is needed that too could come from the NEA's.

[TrevorMonty]

On a Businessweek video interview Anderson mentioned fuel depots at end of interview, like it was an after thought.

[Space OurSoul]

When you want to read something on the WSJ, you click on the link, copy the title, go to google, paste the title, click go, click on the first link that comes up (it'll typically have the logo next to it), and you get the whole article.

Bird is the word.

Thanks for the tip. Although it looks like they've fixed that particular avenue of revenue loss.

(And congratulations, BTW, on whatever recent occasion it was that induced you to put on a tux :-) )

[Vultur]

Yeah, I thought the plan all along was to put up telescopes and sell time on them (first source of income) while using other time on them to find asteroids to mine, then mine water (second source of income) and eventually move on to platinum group metals (third source).

[AdrianW]

According to this article, it appears that the satellite with the torus propellant tank is actually the Arkyd-200:

At that panel, Marquez did reveal a different, more technical, shift in the company’s work. He revealed a new design for the company’s Arkyd-200 series of spacecraft that he dubbed “HomerSat,” after cartoon character Homer Simpson and his love of donuts. “It’s a telescope wrapped in fuel tanks,” he said of the design, showing a telescope surrounded by two toroidal propellant tanks. “It looks like two donuts stuck on top of each other.”

Those propellant tanks give the spacecraft, weighing a couple hundred kilograms, as much as 5 kilometers per second of delta-v, making it very maneuverable. “We can scoot around quite a bit, quite often,” Marquez said.

[simonbp]

When I saw Lewicki give a talk last year (to a room of asteroid scientists), it sounded like their first real return goal was a scientific sample of asteroidal water. That would be valuable the first few times, as the history of where water condensed when is a critical tracer. He also mentioned collecting a bunch of water and using most of it as propellant to get back to Earth.

[TrevorMonty]

There are 2 options for asteroid mining.

1) Mine on site.
Cons: transporting the complete mining plant/ vehicle to asteroid. Mining time maybe restricted as plant will have to quit asteroid before it drifts to far from earth. Distance from earth would require highly automated systems.

Pros: only refined material is transported  back a earth orbit

2) Asteroid capture and return to dedicated refining plant in earth orbit.
Cons: transporting material they don't want.
Pros: telerobotics is possible at refining plant, plant is also not size/mass limited as it is stationary. No time limit on refining.

[AdrianW]

2) Asteroid capture and return to dedicated refining plant in earth orbit.
Cons: transporting material they don't want.
Pros: telerobotics is possible at refining plant, plant is also not size/mass limited as it is stationary. No time limit on refining.

I seriously doubt they'll move an asteroid. Take a comparatively small asteroid, like 25143 Itokawa: it's estimated to weigh 35 billion kg! It's going to take a long time until you impart any meaningful amount of delta-v to it. Even if you scale it down by a factor of 10 on each dimension, you still have a mass of 35,000 tonnes.

Regarding autonomy: Planetary Resources have frequently mentioned that they strive for highly automated systems which "only send back the result, not all the data they gathered" (paraphrased).

[QuantumG]

Take a comparatively small asteroid, like 25143 Itokawa: it's estimated to weigh 35 billion kg!

That's not a small asteroid.

It's going to take a long time until you impart any meaningful amount of delta-v to it.

The great thing about orbital dynamics is it works even if you don't believe it does.

[meekGee]

I very much like the idea of moving small asteroids.  As small as a few meters in diameter.  There must be a huge number of them out there (anyone who played Asteroids and doesn't know about the on-screen object count limit can tell you that) and so you can really pick and choose.

[AdrianW]

Take a comparatively small asteroid, like 25143 Itokawa: it's estimated to weigh 35 billion kg!

That's not a small asteroid.

That's why I said "comparatively small" (it's also the size of asteroid that PR is citing statistics for). But fine, point conceded, let's talk about smaller ones; I'll get to that later.

It's going to take a long time until you impart any meaningful amount of delta-v to it.

The great thing about orbital dynamics is it works even if you don't believe it does.

How about instead of being snarky you present some numbers?

Let's take one of the more powerful rocket engines, like the RS-25, which has a vacuum thrust of 2.28e6 N, so we get an acceleration of 2.28e6 N / 3.5e10 kg = 6.5e-5 m/s˛. So in order to get a delta-v of even 1 km/s, we'd have to fire this engine for 1e3 m/s / 6.5e-5 m/s˛ = 1.5e7 s = 177 days straight. Oh, and have fun harvesting the asteroid fast enough to keep up with the fuel consumption.

Please let me know if there are any errors in my calculation. Note that I intentionally ignored the loss of mass of the asteroid during flight. If this turns out to be a significant amount, the whole mission is moot anyway, since you don't want most of your cargo gone by the time you arrive.

But let's consider a smaller asteroid with one thousandths of the mass (3.5e7 kg, which would correspond to a size of 50m x 30m x 20m) and an engine which is more suited for this kind of mission, like a VASIMIR-style engine with 5N of thrust – for good measure, we'll strap on 100 of them (which will also require tens of Megawatts of power, by the way). Acceleration: 5e2 N / 3.5e7 kg = 1.4e-5 m/s˛, so getting a delta-v of 1 km/s would take about 810 days.

You'll need probably 3-4 km/s delta-v, so we're talking about a 6-9 year transfer time. Probably feasible, sure, but at that point it should make more sense to mine it remotely and return the harvested material on the next close pass to earth.

I very much like the idea of moving small asteroids.  As small as a few meters in diameter.  There must be a huge number of them out there (anyone who played Asteroids and doesn't know about the on-screen object count limit can tell you that) and so you can really pick and choose.

Returning such a small asteroid is certainly interesting for scientific purposes, but I don't think it makes sense for economic exploitation, simply because there's not much value in it.

[TrevorMonty]

Nobody has mined an asteroid before so placing a small (1300t) in earth's backyard to practice on makes alot of sense. Hence NASA asteriod retrieval mission.

Here is VASIMR version of this mission.
http://www.adastrarocket.com/AndrewIEPC13-336-Paper.pdf
NB a lot of travel time is SEP getting out of earth's orbit. For a second retrieval mission it would be starting from HLO so DV/time to 2nd asteroid would be a lot lower. NB we are only using a few tonnes of argon and storage propellants to retrieve 1300t.

I'm not sure mining large asteriods will be feasible even if they are in transit. To do anything you would need to stop any rotation or tumbling which will take a lot of energy (rocket fuel).

[Vultur]

But let's consider a smaller asteroid with one thousandths of the mass (3.5e7 kg, which would correspond to a size of 50m x 30m x 20m)

That's still an awfully big one... Eventually you'll probably get there, but I think the NASA Asteroid Redirect mission people were talking about ~500 t (~5x10^5 kg) which is almost two orders of magnitude smaller.

and an engine which is more suited for this kind of mission, like a VASIMIR-style engine with 5N of thrust

Yeah, definitely electric propulsion is the way to go -- chemical is waaaaay too inefficient.

Returning such a small asteroid is certainly interesting for scientific purposes, but I don't think it makes sense for economic exploitation, simply because there's not much value in it.

This Planetary Resources infographic  (http://www.planetaryresources.com/2014/04/know-asteroids/ ; scroll down to the end of Part 2)says up to 20% water, with a value of $50 million per ton as propellant. If you believe that, then that's 100 tons of propellant = $5 billion for that (EDIT: 500 ton asteroid. If they could really do it for ~$2.5 billion ... I think that's what's been quoted for the NASA mission... that would be profitable, if they could sell it all.)

EDIT: removed extra text from quoted post, finished sentence, added link

[TrevorMonty]

Even a 1000mt lump of rubble has significant value as it still contains 100s mt of oxygen tied up in various oxides. Almost 90% of rocket fuel by mass is oxygen.

[AdrianW]

That's still an awfully big one... Eventually you'll probably get there, but I think the NASA Asteroid Redirect mission people were talking about ~500 t (~5x10^5 kg) which is almost two orders of magnitude smaller.

My comment and calculation was refering to mining asteroids commercially. I agree that for scientific purposes (and for researching&developing future mining techniques on a small scale), it might be better to bring a small asteroid close to earth.

Yeah, definitely electric propulsion is the way to go -- chemical is waaaaay too inefficient.

Absolutely! My calculation for a high-thrust chemical engine was just to demonstrate the infeasibility of moving medium-sized asteroids.

This Planetary Resources infographic  (http://www.planetaryresources.com/2014/04/know-asteroids/ ; scroll down to the end of Part 2)says up to 20% water, with a value of $50 million per ton as propellant. If you believe that, then that's 100 tons of propellant = $5 billion for that (EDIT: 500 ton asteroid. If they could really do it for ~$2.5 billion ... I think that's what's been quoted for the NASA mission... that would be profitable, if they could sell it all.)

That's a big "if". For example, if they are only able to harvest 10% of the resources (due to various inefficiencies) and they can sell the water for only $5m/t (due to increased supply and because some of it will be going to LEO), then that asteroid is only worth $50 million.

Besides, after you've demonstrated properly working technology for mining an asteroid, why would you want to bring it close to earth anyway? You'll need autonomous mining machines in any case, and if you only need to bring back the harvested materials, your propulsion system should be a lot smaller, simpler, and less expensive.

[Danderman]

Please keep this topic about Planetary Resources the company. There are many threads about what kinds of asteroids people like.

[andreto]

It MUST be including launch. Can't cost that much by itself.

[Solman]

 Believe I saw a reference to a talk by Lewicki in which he suggests that concentrated sunlight might have a role to play in asteroid mining but have been unable to find it again. If this is indeed the case it raises some interesting possibilities - in my mind at least.
One is using an approach similar to the Planetary Society's "Mirror Bees" concept for asteroid deflection to actually de-spin and propel an asteroid to Lunar orbit. This has the huge advantage of not requiring any propellant to move the asteroid at all only propellant for mirror equipped spacecraft to station keep with the asteroid.
Another is using concentrated sunlight to bake volatiles out of the regolith and/or to separate oxygen via vacuum pyrolysis.
Then there's my contention that solar concentrator based PV is potentially very high specific power maybe in excess of 5KW/kg electric at 1 AU if using L'Garde concentrator tech and Spectrolab's up to 900 Sun over 40% efficiency triple junction solar cells.
IIRC Lewicki said something about using concentrated sunlight to somehow mine an asteroid without touching it.
This sounds good untill you realize that the jets created by focussing sunlight on meteorite material in a vacuum has been measured by Matloff at 1 km/sec. Harvesting this would seem to require the collecting spacecraft to use thrust to cancel this velocity so I must have misubderstood.