I know, why don't we reopen the Space Shuttle Main Engine production line? You know, there are only so many left now that we can dump in the sea.
I'll get my coat....
There were sighs of relief all round as NASA's Psyche mission finally lifted off late last week. However, the launch highlights more Earthly worries around launch provider competition. The delayed Psyche mission launched to an asteroid of the same name from Launch Pad 39A at NASA's Kennedy Space Center in Florida. Launch …
All these billionnaires have really shaken up the landscape when it comes to accessing orbit.
Yes, it was inevitable as soon as the US government lost interest in space when the race was won. Obviously, government has amply demonstrated that it can't concentrate on anything that won't drive re-election, whether or not that thing would be useful in the long run. The long run, for government, is the next election cycle. That is a pitifully small distance when improving things are concerned (any things, not just Science - take a look at your train infrastructure).
So yay for billionnaires. At least, when their ego is involved (not to mention other personal measurements), they can indeed make a change.
The US government switched interest from space to money. When the Space shuttle proved too expensive to use for regular access to space the same components from the same suppliers got re-shuffled into a jobs program called Constellation. The huge quantities of cash that Constellation spread across every state protected the jobs that matter most: senators and congressmen. When it became abundantly clear that Constellation was more expensive than the shuttle the program was renamed SLS and has become even more successful - at financing politicians.
Billionaire rocket companies have made only two differences to SLS:
*) a rush to get every possible cost plus contract signed with expensive cancellation clauses before the gravy train gets derailed.
*) a desperate search for a replacement gravy train.
All these billionnaires have really shaken up the landscape when it comes to accessing orbit.
Billionaires did, they got the ball rolling again while older private aerospace companies like Boeing and Northrop-Grumman dawdled.
Yes, it was inevitable as soon as the US government lost interest in space when the race was won.
And, fortunately, some of those billionaires had Presidents and COOs like Gwynne Shotwell, who figured out how to get reliable, stable funding for the billionaires' space dreams: the US government. The Falcon 1 flew with US government payloads when no one else would launch a satellite on it. The Falcon 9's development was funded by US government contracts like the Commercial Resupply program - without those hundreds of millions the Falcon 9 wouldn't have flown. The Dragon capsules, funded on US government programs, tested and refined their Dragoneye docking system on the last US shuttle flights. Now Starship is ironing out its development problems on billions of dollars from US government contracts.
The US government is willing to fund multiple routes to the moon (SLS and Starship) just like it funded multiple competing companies to resupply the ISS, which means NASA has been having a blast this past decade. NASA isn't stuck with the old, overpriced ULA launchers for its space probes, freeing money and making Congressional negotiations easier. It gets to issue and manage more contracts for more private companies, meaning more money to skim for itself. And if one of its private contractors collapses because its billionaire CEO has a meltdown or because its airliners stopped selling then NASA has well-funded alternatives already underway.
>>crashing asteroids into the moon
That's a LOT of delta V right there... asteroids are typically either fast moving (the ones that zip past earth and sometimes between the moon and earth) or a long way away (asteroid belt is between Mars and Jupiter).
Applying that dV to an asteroid will be kind of pricey and require some clever orbital dynamics calculations plus finessed propulsion/control to ensure the impact is with Luna and not anywhere else less desirable...
Attitude does not trump physics. That nice Mx. 42656e4d203239 stated that the difference in velocity between the asteroid belt and the moon is huge, and they were quite correct.
Mining the asteroids is feasible, but it's *way* easier to transport the machinery out to the asteroid, mine and refine the materials, then transport back only the stuff you want, which will be the very rare materials that are worth the investment in propulsion to overcome that difference in velocity in either direction. Moving the entire asteroid into Earth orbit is a massive waste of energy.
"Moving the entire asteroid into Earth orbit is a massive waste of energy."
That depends on whether a massive proportion of the asteroid is refinable material or not ... a "dirty snowball" is worth little, a pure nickel iron is more valuable.
Whatever happens, unless it's stupidly valuable and rare materials (like He3), I can't currently see any economic argument for mining/refining material on a space based body for return to Earth.
"I can't currently see any economic argument for mining/refining material on a space based body for return to Earth."
More likely the economic argument is for mining / refining material on a space based body to use in a space based project.
Historical cost-to-orbit is over $10k/kg (although Falcon Heavy estimates of cost-to-orbit are as low as $1500/kg), which means that for most industrial materials that might be used in space construction, the cost of getting the material to orbit far outstrips the material cost on earth. Mining anything in space is bound to be costly, but you just need to get the cost to 'lower than launch cost' for it to be economically feasible.
What is pure nickel iron worth even if you had it conveniently in Earth orbit? Not worth the cost to bring it down the gravity well to Earth compared to mining it here, that's for sure! It just isn't that valuable per ton. Having it in orbit would only make sense if you wanted to build something in orbit that required massive amounts of metal.
For something like gold or platinum, sure, but you'd have to mine it in situ and only transport the good stuff back - so unless you require people on site operating the mining equipment you may as well mine it where it is now rather than move it.
Lobbing an asteroid at the Moon would be a LOT easier than trying to insert it into Earth orbit. deltaV is almost irrelevant - you're not trying for a soft landing.
And the idea that you might miss the Moon and hit the earth instead just shows you've never played Elite Dangerous. Missing the Moon and hitting the Earth instead by accident would be like throwing a piece of cotton over Niagara Falls and accidentally having it thread a needle someone else was holding a quarter of a mile away from the one you were aiming for.
" it's *way* easier to transport the machinery out to the asteroid, mine and refine the materials, then transport back only the stuff you want"
It's way easier than that to just transport a thruster and some fuel out to the asteroid to nudge its orbit so it crosses the path of the Moon in a year or three. That's all it needs to do - it doesn't need to slow down at all - in fact it's arguably preferable if the speed on impact is huge - the innards of the asteroid would then be spread out over the surface of the Moon in a more easily accessible form than would be the case if it "landed" more or less intact. Then "all" you need to do is get your mining machinery to the Moon.
All of this is predicated on the assumption that nobody gives a shit what hits the Moon or where. It'd be a terrible shame if the impact site turned out to be right where the Eagle landed.
If you form 8000kg of iridium into an Orion capsule shape then add about 1000kg of heat shield and parachutes you have something you could safely send to Earth. At 2020 prices that would be worth $400M - except the world market for iridium in 2020 was only 8000kg. Humans are exceptionally good at not needing iridium.
$400M is a tight budget for sending any large vehicle to the asteroids. To make a profit, the vehicle has to manufacture a steady stream of precious metal capsules plus (solar electric?) engines plus solar panels plus propellant (cheap metals?).
Much easier to forget the asteroids and precious metals. A working Orion capsule is worth more than double one made of iridium.
"just transport a thruster and some fuel out to the asteroid to nudge its orbit so it crosses the path of the Moon in a year or three"
Not sure if there is any quick-and-easy back-of-the-envelope calculation of how much deltaV would be needed for that, but it would be interesting to get an rough idea... it might turn out to be two dozen thrusters and 'quite a bit more than some' fuel
Err, what do you think would happen if a sizable asteroid collided with the moon without being slowed down? I would worry about a big crater, debris being flung widely over the Moon's surface, possible moonquakes, some of the debris being flung into the space between the Earth and Moon. Any installations on the Moon could be negatively affected by this. This probably wouldn't be as bad as an asteroid hitting the Earth, but still it doesn't seem like a good idea to me.
>Any installations on the Moon could be negatively affected by this.
And if I live to see "any installations on the Moon", I'll be surprised. Space:1999 turned out not to be a documentary.
> I would worry about a big crater
> debris being flung widely over the Moon's surface
> possible moonquakes
Again - so what? It's the MOON. It's not like there's anything there. Not even sea, and birds, and fish, and twenty thousand tonnes of crude oil, and a fire, and the part of the boat the front fell off. It's outside the environment.
> some of the debris being flung into the space between the Earth and Moon.
There is a LOT of space between the Earth and the Moon...
Again, if you're not getting the idea of scale, just play Elite Dangerous long enough to get an access permit for the Sol system. When you've done that, fly around in that system without engaging supercruise (the in-system FTL drive). You'll be limited to "just" way, way faster than anything we can build right now, and the game will be unplayable because the distances... no, the VOLUMES are, well, astronomically huge.
Crash an asteroid into the Moon, and yes, it'll splash some rocks into the sky. And maybe, possible, some of them MIGHT burn up in the Earth's atmosphere years or millenia later. But seriously - what are the odds, vs. all that lovely cadmium/niobium/whatever RIGHT NOW. Yay capitalism, and so on.
They have been imaged several times on their way out. In this image, the telescope was tracking on Psyche and its booster, which is why all the stars are trailed. Psyche is the fainter of the two dots at center. They were both about 190000 km away (roughly half the distance to the moon).
And a Romanian astronomer got this video of the booster (Psyche was too faint to show up in this one) a bit later and slightly further out.
(The images were not made "just for fun", though that was a part of it. JPL will do an excellent job of tracking the spacecraft, but our knowledge of where the booster is going comes from images of this sort. In particular, we'd like to be able to identify it if the asteroid-hunting surveys catch it again in a few years; we find "mystery" objects returning from heliocentric orbit every now and then.)
That's an asteroid that's been estimated to have a density of 75 g/cm^3 - 3x that of the densest known substance on Earth. While it is possible our estimates of its mass and/or size are way off, it has been known since the 1850s and therefore studied a long time.
If nothing else simply performing a close flyby on the way elsewhere would allow for very accurately measuring its size and mass, and whether it is worth a dedicated mission.
Don't believe a word of it, unfortunately.
(33) Polyhymnia has gotten a rash of publicity recently. Some nuclear physicists did some theoretical computations of the density of extremely high-Z nuclei (well beyond the currently known transuranic elements), and found that in an expected further "island of stability", you'd get extreme densities. All quite plausible.
They then uncritically accepted some of the really high estimates for asteroid densities. Formally, the density for (33) Polyhymnia is 75.28 +/- 9.71 gm/cm^3. However, the nature of computing asteroid masses is that you sometimes get fluke results that are either negative or obviously way too high. You need to report these so that people understand that any asteroid mass value has to be treated with caution. But it appears to have misled our nuclear physicist colleagues. (Asteroid sizes are usually determined with decent accuracy; it's the masses that are very hard to get.)
(I am the author of a program that is used, among other things, to determine asteroid masses based on their perturbations of other asteroids. The recent publicity didn't go over well with those of us in the asteroid research community. There are some very solid mass determinations out there, but this wasn't one of them.)