Was it the Pixar image
of being too wretchedly cute which caused them to quit? Are they plotting robotic revenge such as redirecting asteroids in our direction with their remaining fuel to get back at us?
NASA has said goodnight to its two experimental CubeSats, sent into space to monitor America's InSight probe as it landed on Mars, after failing to communicate with the gizmo duo since January. Scientists relied on the mini machines, affectionately named Wall-E and Eve after the robots in the Pixar film WALL-E, to relay …
According to NASA data, they flew freely behind the probe all the way:
"The two CubeSats are designed to separate from the Atlas V booster after InSight's launch, then travel along their own trajectories to the Red Planet. "
So they actually tested CubeSats with a very long planned lifespan for the first time. That's why they sent two.
The space between stuff in space is mind-boggling, but instead of just quoting Douglas Adams, or imagining it to be as littered to the point of obscuration as shown in other near-Earth orbit scenes from WALL.E, here's another mind-bending image...
Sir James Hopwood Jeans, in his 1933 Christmas Lecture at the Royal Institute said this:
"If we take six wasps and set them flying blindly about in a cage 1,000 miles long, 1,000 miles broad and 1,000 miles high, we shall ... have a model of the distances between the stars." If the wasps are stars, imagine firing a grain of sand through that 1000 mile cube - would one hit a wasp? On that scale, the grain of sand represents a small planet. Scale is, as they say, entirely relative.
There are bigger bits of debris from over 4 billions years ago floating about, an none of them got hit by deep-spce probes. It would take an incredible amount of bad luck (or accurate targetting) for a future spacecraft to collide with these two cubesats, and any planetary body they encounter wouldn't notice the impact - they'd burn up in the atmosphere of any planet or moon with one.
"The space between stuff in space is mind-boggling"
Indeed it is, but we're quite likely to start doing this more often, and always targeting 'at or about' planetary orbits, so these will probably be moving with an aphelion somewhere at or beyond mars orbit and a perihelion at or about earth orbit - and on a well aligned plane.
Given that we will always want to be launching for an efficient transfer, and could start launching alot more than a couple of these things... the density will always be miniscule, but something to either make them *really easy* to identify (passive reflectors) or plotting their course to include either aero- or litho- braking at some defined point beyond their mission doesn't seem completely impossible.
"wonder if/when they next encounter a planetary body"
Given their orbit, the only planet they're likely to encounter in the next few thousand years is likely to be Mars, and when they do they'll burn up leaving nothing more than a tiny bit of soot.
Still, you seem to be worried, so lets do some maths:
Obviously we can't measure the size of all of space, but then we're only really interested in the bit around us, so lets imagine the disk of the solar system, out to Mars orbit, and because most stuff orbits in the same plane, we can imagine it as a disc only as thick as the Earth (12x10^6m).
So, radius of Mars orbit (ish, it's really an ellipse) is 228 million km, or 228x10^9m
The area of our disc would then be 1.63x10^23 m^2, and the total volume would be 3.7x10^31 cubic metres (that's 37000000000000000000000000000000 cubic metres, more or less).
If we assume that each one of these cube sats is one cubic metre (they're smaller than that, but it's close enough), I hope you can see that 1 into 3.7x10^31 is a tiny, tiny fraction. And this isn't even the whole solar system, it's just a thin slice of the area out as far as Mars.
Space really is quite large.
"Still, you seem to be worried,"
I'm not worried, I was just wondering...
In the same way we once thought the oceans to be infinite in their capacity to deal with whatever we threw at them - at some point the amount of crap we leave lying around interplanetary shipping lanes might cause an issue.
"NASA estimated that Wall-E is more than a million miles (1.6 million kilometres) past Mars, and Eve is further away at almost two million miles (3.2 kilometres)."
Er, 3.2 MILLION kilometres please.
NASA spokesperson Dougal Maguire explained "that cubesat is very small....the other cubesat is far away"
After polluting the space around Earth, Humanity begins to pollute the space around the Sun... Aren't we smart?
The space around the Sun is full of all kinds of débris, it's only the lack of adequate telescopes and the time it took us to move away from the ideas of Aristotle that cause most people not to realise that the Solar System is full of litter already.
Once you get beyond the orbit of the Moon we really are not doing anything to increase the rubbish density.
Were it not for Jupiter's huge influence on the inner system, that zone would be far more cluttered, we'd be getting hit quite often, and serious impactors would be common enough to possibly suppress higher life forms here on Earth.
With Jupiter in place, any debris not in safe, non-resonant orbits tends to eventually collide with Jupiter or be ejected from the inner system entirely. And since the safe orbits are where the inner planets (and the asteroids) reside, even those locations are unstable for the debris (except for the asteroid belt, due to the lack of a major planet there).
Thus it's pretty clean around here, other than recently created stuff caused by collisions, which can be considered a "background level" of junk that remains stable over time. Our recent additions to that junk level are pathetically small and it's going to take a much larger effort before we can call ourselves proper space polluters. Only in low earth orbit is our footprint even detectable, and that's the least stable place of all, due to atmospheric drag.
Only in low earth orbit is our footprint even detectable
Even detectable, but enough to create incidents.
Collision of Cerise with Space Debris
ISS crew take to escape capsules in space junk alert
astronaut Tim Peake shared a photo (above) from inside the ISS's Cupola module documenting what kind of damage this debris can do to the satellite. The European Space Agency says the piece of debris that caused this particular chip was "possibly a paint flake or small metal fragment no bigger than a few thousandths of a millimeter across."
But hey, let's do business as usual: let's continue to don't give a fuck about the consequences of our actions, this behavior works so well on Earth.
> "But hey, let's do business as usual: let's continue to don't give a fuck about the consequences of our actions, this behavior works so well on Earth."
Actually it does. Here on Earth, all microscopic bits of debris we create merely by operating machinery, walking around, and scratching our arses, is quickly absorbed into the environment and basically vanishes.
Not so in orbit however! There, such tiny bits just float away, adding to the "junk" level and occasionally striking our space stations quite hard. These tiny bits make up the vast bulk of the current "space junk" around our planet. We didn't intend to put it there, it's just hard to prevent, regardless of any fucks we may give about it.
Yes, let's try to clean up the larger pieces that got left up there, but criticizing our space exploration efforts as "bad" because of some paint flecks smacks of gratuitous whinging.
Why should we add junk to debris? In the 60s, nobody realized the consequences of letting junk floating around Earth, space was so immense after all and there were already a lot of debris, some of them hitting Earth every day.
It seems to be the human way: Après nous, le déluge!
It's amazing what you can fit in a briefcase these days, e.g.
- a Mars probe
- a nuclear weapon
- two bags of grass, seventy-five pellets of mescaline, five sheets of high powered blotter acid, a salt shaker half full of cocaine, and a whole galaxy of multi-colored uppers, downers, screamers, laughers...