What did we say about Tesla's self-driving tech? SpaceX Roadster skips Mars, steers to asteroids The final rocket burn of the SpaceX craft carrying Elon Musk's personal Tesla Roadster into the cosmos pushed the billionaire's flash jalopy much further than anticipated. It's now heading out toward the Solar System's asteroid belt rather than swinging close by Mars as planned. Yesterday, SpaceX launched its powerful Falcon …
The comment in the article "The payload was supposed to get into an orbit around the Sun, and skim Mars" is simply WRONG - it was always going to be a heliocentric orbit which just happened to go out as far as Mars! Had they planned to go anywhere near Mars, with a risk of crashing, then they'd have had to spend months sterilising the car for planetary protection.
So the fact that it now happens to go a bit further is no problem, and not an error - in fact they actually said that they'd burn the fuel to exhaustion, and see how far/fast it would go.
Sky News made the same mistake, and it's not surprising from them, but I would have expected better from a space-faring publication
"So the fact that it now happens to go a bit further is no problem, and not an error"
Who said it was a problem? We're just pointing out that it's overshot. Musk tweeted the final burn was going to send the thing "to Mars". It was heading to Mars. It's going to miss Mars by a much greater distance than expected.
Christ, it's a flying PR st- car. A flying car in space. It's funny as fuck.
Jeez, tough crowd! ;-)
C.
Warning: A bunch of programmers hang out here.
Programmers spend half their lives dealing with computers that do exactly what they are told even when it is not what is wanted. They spend the other half of their lives trying to get humans to explain clearly what they want so they do not throw a tantrum when they get what they asked for.
Dave Harvey clearly believes you are capable of communicating with the precision appreciated by programmers. Take it as a compliment because they do not make the effort when they believe there is no hope.
Problem?
During a press conference after liftoff, Musk said it was dicey whether the second stage would power up at all. The fuel could have frozen, the oxygen boiled off, or the avionics failed, as the rocket spent more than five hours in our planet's high-radiation Van Allen belts before firing up.
I'd rather like my space craft to be a bit more reliable, and for people to retain domain knowledge. Domain knowledge? There are enough (>=1) old-time rocket scientists who managed to point out problems with fuel, valve, and time-in-space problems with certain NASA missions, namely: don't use certain fuels for missions longer than a certain duration. I would have hoped that someone would have been able to calculate the thrust correctly, ensured that fuel did not freeze, shield the avionics, etc.
I would have hoped that someone would have been able to calculate the thrust correctly, ensured that fuel did not freeze, shield the avionics, etc.
Oh, come on you grumpy old git (*). Stop telling the kids to get their bikes off our lawn as if it is reserved for our mobility scooters. It is a reality that nobody keeps to Bismark's old saying: "Only idiots learn from their own mistakes, smart people learn from the mistakes of others".
(*)I am in that category myself nowdays too.
I'd rather like my space craft to be a bit more reliable, and for people to retain domain knowledge. Domain knowledge? There are enough (>=1) old-time rocket scientists who managed to point out problems with fuel, valve, and time-in-space problems with certain NASA missions, namely: don't use certain fuels for missions longer than a certain duration
And even though Ignition! has long been out of print (there's a reprint coming out), there are PDF versions of it aplenty. Very informative, and any rocket surgeon who hasn't read it shouldn't be anywhere near the propulsion side of things.
"I would have hoped that someone would have been able to calculate the thrust correctly, ensured that fuel did not freeze, shield the avionics, etc."
Calculations rely on physics and experimental data. Whilst the physics is know the experimental data is thin on the ground as I don't believe anyone had ever put a kerosene based rocket stage into deep space. As you say you normally use fuels more suited to the job in hand, however they used what they had. No doubt besides having some very cool videos of a car in space they now have physical data so support if oxygen boil off and kerosene freezing matches their calculations and how much of the boiled or frozen fuel is actually usable to provide thrust. They also now have physical evidence about how cosmic rays (that are almost impossible to shield) affect their non-radiation hardened computer systems. All nice to have spin offs from a publicity stunt.
"I'd rather like my space craft to be a bit more reliable..."
How do you think reliability is achieved? If any bit of technology worked reliably on a first attempt there wouldn't be any need for testing.
"There are enough (>=1) old-time rocket scientists who managed to point out problems with fuel, valve, and time-in-space problems with certain NASA missions, namely: don't use certain fuels for missions longer than a certain duration"
And how do you think they gained that knowledge and expertise?
As far as first flights of orbital launch systems go, the first flight of Falcon Heavy was spectacularly successful.
@diodesign,
Christ, it's a flying PR st- car. A flying car in space. It's funny as fuck.
No it's not. It's $billions space littering, especially as its orbit now crosses that of Mars, and it isn't sterile and risks polluting the place ruining it for science should it hit. It may now hit Mars, even if that takes a long time. It was supposed to be put into an orbit that didn't reach Mars, but they cocked it up.
So when does dropping litter on the street ever seem funny? Why does essentially the same kind of careless act by a show-off billionaire attract your mirth?
Actually it doesn't. The orbit is inclined out of the plane of the solar system, meaning it will pass 'over' or 'under' Mars in its orbits. It DOES get closer to earth so might at some point get another kick that way, but that would probably send it further out of plane and further out into the solar system. It's unlikely this car will ever end up on Mars unless someone goes to recover it and land it there.
"It may now hit Mars, even if that takes a long time"......
Whilst on paper orbits look 2D and intersect they are actually 3D and don't. Maybe in a billion years or so the orbit might have been perturbed enough for an impact but after a billion years of sterilization in space it's going to be Mars contaminating the car and not the other way around.
No it's not. It's $billions space littering, especially as its orbit now crosses that of Mars, and it isn't sterile and risks polluting the place ruining it for science should it hit.
Unfortunately unless science can provide a profit it will always come second to commercial gains.
So when does dropping litter on the street ever seem funny?
I agree with you, but the simple answer is we have limited space on earth, there is a lot more room in space - "That's why they call it space"
>>> t's $billions space littering, especially as its orbit now crosses that of Mars, and it isn't sterile and risks polluting the place ruining it for science should it hit.
In the words of everyone space guru:
Space is big. Really big. You just won’t believe how vastly hugely mindbogglingly big it is. I mean you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space."
The Hitchhiker’s Guide To The Galaxy, The Hitchhiker’s Guide To The Galaxy
The probability of it actually hitting Mars, or anything else in the solar system for that matter, in mine, or yours, or even our great grand childrens lifetimes is so astronomically small that you might need an infinite improbability drive to calculate it.
"
So when does dropping litter on the street ever seem funny? Why does essentially the same kind of careless act by a show-off billionaire attract your mirth?
"
Imagine that you are walking along a London street, and a fleck of dandruff falls from your scalp into the gutter. Would you be quite happy to pay a £75 fine for littering? Because you will have introduced 1000's of times more litter into the city than this test launch has created in space.
There is a far higher risk of Mankind being destroyed by a large space rock hitting the Earth than there is of that Tesla Roadster hitting any planet.
In any case, if it starts heading toward a planet, the robotic mannequin is programmed to quickly apply the brakes and steer out of the way :-)
> Jeez, tough crowd! ;-)
*If* the aim was to get into a particular orbit, then this is an epic fail on the part of the control systems to be so far off. Unfortunately that seems to be how it's being reported (or at least reports I've seen, but I haven't tried hard to read it all)
*If* the aim was to burn the rest of the fuel to exhaustion just to kick the car as hard as possible, then this is not a fail.
Still fricking awesome to watch.
So the fact that it now happens to go a bit further is no problem, and not an error - in fact they actually said that they'd burn the fuel to exhaustion, and see how far/fast it would go
As far as I can see it is still in a heliocentric orbit but it's a lot bigger than intended. It's orbit now crosses that of Mars. It's going to do that about once every year forevermore. One day it's going hit Mars, and that is a problem because as far as we know that Tesla hasn't been prepared as sterile. If it hits Mars, we'll never be sure of the results of any was-there-life-on-Mars experiments; we might be detecting a Musk booger.
For SpaceX I don't see how this can be good news. Customers want accurate launches, not wildly off the mark launches. I know they wanted to burn the stage to fuel exhaustion, but there's no need to see how much energy a booster produces in space; that's what the test stand is for.
> One day it's going hit Mars
Have you actually calculated the probability of this thing striking Mars in, say, the next 10 billion years? If so, what answer did you get?
Whilst we're not talking about the whole universe here, the solar system is still mind-bogglingly big. And if there is even a minute tilt between the plane of Mars' orbit and the plane of Tesla's, the chance of impact is vanishingly small.
You might also want to work out the probabilities of hitting Mercury, Venus and Earth while you're at it.
Here's a handy page to give folks who are unclear on the concept a rough idea of how much vacuum there is between planets ... And please remember, this is only a one dimensional representation!
According to https://spaceflightnow.com/2018/02/08/starman-puts-earth-in-the-rearview-mirror/, it's orbit is pretty much as originally planned. It will miss Mars by about 69 million miles (which is 2/3rds of the Earth-Sun distance, so a long way). Furthest distance from Sun will be 158 million miles. That's far short of Ceres (250 million miles), but relatively close to the inner asteroid belt (180 million miles).
It's not going to hit Mars any time in the next few thousand years. By the time it does, we'll be living there and will have contaminated it thoroughly.
"The comment in the article "The payload was supposed to get into an orbit around the Sun, and skim Mars" is simply WRONG - it was always going to be a heliocentric orbit which just happened to go out as far as Mars!"
WTF?? A heliocentric orbit is an orbit around the Sun, and how is going out as far as Mars not the same as skim[ing] Mars?
You've just claimed that what was said in the article was wrong and then said exactly what the article said.
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Ok using his personal roadster as a test payload is way better than using a block of concrete. However there is also an upside for him in that he can write the vehicle off as a tax loss, and get a brand spanking new one in the process. Who said he was just a silly little boy?
You get tax write offs for sending your stuff to the (celestial) dust bin?
Does everyone get to do that, or only the 1%? Because I have lots of stuff I could dispose of, and if I can get a tax write off for doing it, so much the better.
Admittedly putting my old stuff out on the kerb isn't nearly as exciting as shooting it into space––
I was mildly disappointed that they couldn't find some real science experiments to toss into the payload along with the roadster.
How many other opportunities for potentially free trips of that magnitude into the solar system are you going to get? I'm sure the world's universities could have quickly come up with some research that could be done on the cheap.
Generally, no-one wants the hassle of "real science experiments": assuming you can find a source of "real science experiments" that won't mind the unpredictability of the launch schedule (because the payload is going to be delivered to Canaveral, bolted to the rocket, and then ignored for as long as it takes to get the rocket ready), the "real science experiments" would (obviously) be on their own for telemetry, etc. because the rocket scientists are going to want to be able to co-opt anything they want. Plus, the "real science experiments" had better be 100% guaranteed not to fail in a way that might damage the launcher.
NASA calls the things "mass simulators" for a reason. And I'd say the car-in-space gimmick is probably as valuable to Space X as anything they could carry in terms of publicity. I mean, who bothered to report on Dragon's maiden flight's cargo? (a soft cheese, as it happens).
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I mean, who bothered to report on Dragon's maiden flight's cargo? (a soft cheese, as it happens).
Well, in that case, the fact that they didn't reveal it until after the flight had happened and 90% of the news had already been reported, leaving it as a side-note for bloggers etc to comment on after the fact did that.
"And I'd say the car-in-space gimmick is probably as valuable to Space X as anything they could carry in terms of publicity."
Yes, definitely. It's been one of the topics of conversation at every site I've visited since the launch. I've heard comments from people who obviously have no interest in "space stuff" normally because they were gob-smacked at the booster landing and didn't know that was possible. Oh yes, and thought the image of a sports car in space was cool.
As a publicity stunt, I'd say it's succeeded beyond all expectations.
You don't need science experiments - that will trow politics into the mix. What he needed was an advert from the marketying crowd.
He picked a Tesla, which gave him a nice publicity boost. If I were him I would have added a pointable low-power astronomical telescope - maybe several - a stability system and a 2-way communications link. Those are all low-cost and pretty much standard off-the-shelf kit. And that would have meant that he could have provided 'space' pictures over the internet to hobbyists for as long as the stability system/comms link held out. Who knows - the 'probe' might come within reasonable viewing range of an asteroid....
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