Quality Control
I'm guessing that the QC on this software upgrade surpasses anything that MS have ever contemplated!
It's not as if they have say ~10'000 users / satellites to test it on.
The European Space Agency's (ESA) Mars Express orbiter is getting a software refresh as a reward for 14 years spent circling the red planet. Mars Express arrived in orbit at the end of 2003, and set about collecting high-resolution imagery of the surface, spotting water and detecting methane. Not too shabby for a spacecraft …
Fully agree, Microsoft don't test anything, they rely on the users to be their beta testers.
As they are doing an upgrade, I wonder if anyone has considered other features ?
They already have telemetry, but I wonder if they will add a pointless app store and enforce the use of a second rate browser and a gaming console for not apparent reason too.
To be fair, while the pucker factor of restarting something like this so far away is never going to be zero, it shouldn't exactly be that hard to make something damn near update-proof*. Just make sure you have enough memory to store at least two whole OS images and ensure that unless the updated OS can present suitable proof of successful two-way comms with Earth within a convenient time frame following an update (or on an ongoing basis), it gets mercilessly booted by a hardware watchdog** back into the original OS image which tells you this and asks "okay, now what?"
*don't even THINK about "completely update-proof". No such thing. The Universe is on Murphy's side.
**by which I mean multiple redundant independent watchdogs of course. Paranoia IS a virtue.
We really need to start investing in generic deep space comms to get data from these remote probes back to Earth in a more organized manner.
I know sending a Tesla rover to a distant planet is far sexy and easier to sell, but it's these kinds of infrastructure items that people like governments need to push through.
Well actually, Mars Reconnaissance Orbiter is the current "comsat" for Mars. It relays info from all the rovers.
NASA's praying it keeps going, because there's no replacement in the pipeline.
https://spaceflightnow.com/2018/04/09/nasa-is-counting-on-long-lived-mars-orbiter-lasting-another-decade/
"We really need to start investing in generic deep space comms to get data from these remote probes back to Earth in a more organized manner."
The Deep Space Network would be sad that you've apparently never heard of it, but it can't get sad because it's an international collaboration of radio telescopes and antennas, not a person.
A blue screen of death is difficult to fix from 150,000,000km away. Surely the have a watchdog timer available and it is not beyond the wit of man to make sure the bootloader reverts to the last known good OS image. The article already states that they have managed to squeeze in the new image alongside the running system.
"But who/what watches the watchdog?"
That's easy. The watchdog timer supervisory circuit.
And what watches that?
That one's easy. The only explanation for why these spacecraft keep massively exceeding their mission times is because a black monolith is keeping them going to see what the humans do next.
remember it... I had it! If memory serves me well, was a flimsy floppy plastic that needed a 2p to hold it down so it would spin.... knowing my old folks, they still have it tucked away somewhere in a storage box....
... ah.. .actually it was the Pinky & Perky version I had......
Nearly all these things are Vxworks or bare metal.
Quite possibly. I still have some Mars Rover models from my days at Windriver..
(Those caused some red faces in Marketing - they had them made to celebrate VxWorks usage by NASA in the Mars missions and were about to sell them when NASA pointed out that the agreement to use the NASA logos and designs had never been granted and that, were the models to be sold, no more business would be forthcoming. So all the models were given out to staff on the strict understanding that they were never, ever to sell them..I still have one and so does my then-space-mad nephew)
IIRC that's what hurt most of the copies of them on Hubble.
But these days aren't most of them laser based (certainly for large passenger jets since the mid 80's IIRC) ?
The best seem to be the solid crystal lump types, however they seem to need a "dither" spring that (I presume) can age).
So how do they "age"?
Mind you. Full OS upgrade from 140 million miles away and works right first time. Impressive.
Depends what you mean by "still". This guy seems to be about 20 years old and heaven knows when they started planning the hardware. I don't know when the first micro-mechanical gyros came in or how good they were (or indeed are, even now, for a mission likely to last several decades). It is entirely possible that they weren't an option.
As I noted there have been no new "spinning metal" gyroscopes installed in transatlantic passenger planes since the mid 80's, say 35 years?
Ariane 4 was flying with laser gyroscopes since it was the failure to cope with the upgraded performance of the A5 rocket that caused the maiden launch of A5 to fail.
Hence my expectation that space navigation grade laser gyroscopes are a thing by now and my surprise they are still a problem.
Mars express was launched just a tad shy of 15 years ago. Take 5 years to build and start of design 10 years before that, the tech used was at best state of the art 30 years ago. Most likely it was well proven tech 30 years ago (and thus at least 40 years old by now). I'd think it was possible for Mars Express to still have mechanical gyro's for its orientation/navigation platform, however, that's not the issue here. The issue is the attitude control system. The article incorrectly uses Gyroscopes for what should actually be called Reaction Wheels. There is also an attitude control system called a Control Moment Gyroscope, but that's not what is on Mars Express from the info I can find. Mars Express uses "simple" Reaction Wheels.
@ John Smith 19 "...my surprise they are still a problem."
Read the above posts again.
These are big massive momentum gyros for rotational force, not wee feisty gyros for sensing. The craft pushes against them to rotate, because there are no convenient rocky surfaces in Space.
Why don't you try reading my replies instead?
I got the point about the difference between actual gyroscopes and reaction wheels/Control Moment Gyros (which were used on Skylab and are being used on the ISS).
The challenge for your idea is how to build a passive magnetic bearing, so all the power is in spinning up (or down) the rotor? With a conventional bearing the relationship between the rotor and case is guaranteed. With any imbalenced force the rotor starts to drift off axis.
IIRC "Halbach" arrays of magnets are the most efficient for generating force but you still have to null out any imperfections. That's a continuous current drain.
It looks like reaction wheel/CMG bearing failure will (along with battery failure) be the most probably life ending component for space probes for the foreseeable future.
Just because *you* can't imagine how it would be accomplished, doesn't make it impossible.
By the way, I never wrote "passive". You added that yourself.
One advantage of being well versed in a very wide range of technologies is that I can quickly assemble a mental list of existing examples for each requirement.
Your "logic" has proven that those little magnetically suspended globes cannot be given a quick spin. Thus proving that you can fool yourself with your logic unbounded by being familiar with examples of existing technology.
The magnetically suspended globes have an active feedback system.
In other words, "Mag Lev" bearing-free gyros for spacecraft reaction wheels clearly is an entirely possible technology.
Is it worthwhile? I don't know.
But there is no objection to the feasibility that withstands familiarity with already existing technologies.
And don't add "passive" yourself, and attribute it to me.
Gyroscope = measure attitude, yes you can use laser ring gyros
Gyroscope = reaction wheels or control moment gyroscopes, no there is no substitute for real mass
These "gyroscopes" aren't used to measure position, they're used to change your direction without using rockets. Imagine holding a spinning bike wheel and try and tilt it. In a spacecraft you use it as a "fixed" frame to push against.
YAAC - great post.
The space agencies need to look into something like MagLev gyroscopes, where the spinning mass is untouched except by magnetic fields. No bearings to wear out. The forces would be applied by magnetic effects only, including suspension. Last "forever".
Suspension might be around the edge, as opposed to an axle, if the higher edge speed works better for MagLev.
Difficult to hold a gyroscope in enough directions with magnetic bearings (basically hard to stop it walking along the axis) and you need to connect a motor drive anyway so you can't make it totally free floating.
In Earth orbit you can replace the gyro with an actual bar magnet and 'push' against the Earth's field - Mars doesn't have a magnetic field
YAAC "Difficult to hold a gyroscope in enough directions with magnetic bearings (basically hard to stop it walking along the axis) and you need to connect a motor drive anyway so you can't make it totally free floating."
If Magnetic Levitation can support the Shanghai Maglev Train at 430 kmh, then it should be possible to support a 7kg spinning disk. Yes it would be complicated. But replacing the mechanical bearings with magnetic levitation would mean that it could last forever, in principle.
"connect a motor drive anyway" <- that's inexcusable.
Do you realize how electric motors work? They use magnetic fields to drive it around. The only thing that has to touch the rotor are the bearings. Which is where Mag Lev comes in.
The complicated aspect would be the straightening control system; that would be a fairly complicated control system of sideways pushing magnets synchronized. Very complicated.
Perhaps a spinning sphere would be better.
Supporting a maglev train is easy. Gravity pushes down, magnets push up, put magnets on sides facing slightly inwards to act as flanges.
Supporting an axle inside a magnetic bearing requires a uniform inward field from all angles - you can't do this with fixed permanent magnets (Earnshaw's theorem) you can do it with a bunch of electromagnets and a complex control system. But you lose energy from eddy currents, which can also cause speed jitter which is a problem in a precision platform - like a space telescope.
Remember you don't just need to support a free spinning wheel, you need to be able to put a torque on it. If your magnetic suspension can only resist a very small torque then you need to build (and launch) a much bigger flywheel.
With you now.
That's a whole different thing.
I prefer the idea of CMG's. Once spun up they need relatively little power to keep spinning and low power to alter the axis of rotation.
One thing I've not seen explored is the idea of a dense fluid in a circular pipe, perhaps with some inert gas, so you form lumps of it. I'm thinking of a low melting point alloy to make it conductive with say Tungsten beads to make up the weight.
The best seem to be the solid crystal lump types
Yeah, but do they use the right crystal types to generate the right mystic energies? Otherwise, you might have a Libran satellite being given a crystal more suitable for Pisces and that would never do!
(Yes, I think it's bunkum too but I've worked with very intelligent and capable people that seriously think that way..)