Ahh...the old 'drain the power...
...to turn it off and on again' fix.
NASA has updated the status of its once-was-lost, now-is-found IMAGE satellite and revealed the bird's power supplies are operational. The space agency will therefore attempt to revive the mission – if it can find money to fund the effort. As The Register previously reported, IMAGE (the Imager for Magnetopause-to-Aurora Global …
Why wouldn't they build some sort of deadman switch in the satellite using a simple microcontroller such that if it didn't receive a signal from the ground over a certain period of time, or didn't see any evidence that the CPU was running, or other 'catastrophic' conditions that it would reset the power itself?
If the software running on the spacecraft's main system suffers from halting problems then you've already lost: you don't write programs to run on spacecraft which try to solve problems which only may have answers. So a watchdog reset is perfectly straightforward: 'if watchdog reset is enabled, and if the main CPU has not reset its timer in n seconds or nothing has been heard from the ground in m seconds, power cycle the system'. I'm sure spacecraft have such things.
"...some sort of deadman switch..."
The phrase you're searching for is "Watchdog Timer".
An overly-simple example is a 555 timer chip, where the properly functioning software gives it a periodic pulse to prevent the timer chip from resetting the CPU. If the software falls over, then the CPU is (hardware) reset / rebooted. In the real world, there are such hardware watchdog timers built-into many CPUs. Or built-into a related support IC.
Another related phrase is "Safe Mode".
I was actually told that a couple of month ago at an Airport...
"We're sorry for the delay, there is minor fault on the aircraft, engineers are going to cycle the system to try to get it cleared."
Nice attempt at cover up, but I can recognise and "off and on again" at 300 yards.
Sometimes I really wish I wasn't a techie about to get on a plane after hearing that.
(Just for clarity, I didn't die).
What do you mean, "we broke something when we came out of warp"? Nothing should be here according to our info. What??? It looks like something made by another lifeform? Oh sh*t, now that's torn it, they'll be docking another of my tentacles if anyone finds out. Tell you what, let's take it with us, get it fixed and then put it back in the same place next time we're around these parts.
NASA conducts a failure review whenever any mission ends unexpectedly. It's good practice. But when an amateur manages to find that a satellite has revived itself, and NASA had no idea, that's, well, troubling.
The FRB stated: "It is unlikely that the IMAGE mission can be revived. However, the October 2007
eclipse season may permit a Transponder SSPC reset (and a re-powering of the
Transponder), but this is not certain given that the main bus reset level may really be 21
However, they did say: " If revival occurs, the mission should be able to continue as before with no limitations."
NASA doesn't have the budget to keep a mission "on hold" indefinitely. NASA kept listening until somewhere in 2008 IIRC then declared the mission lost and moved on. It took until at least end of 2014 before the satellite came back online. NASA did it's due diligence, concluded the mission was over when the time window for a likely reset was over and got on with other missions.
But occasionally a faulty alignment/thruster/incident of somesuch, can send a solar panel or power state off. Thus until it then realigns due to natural orbit, alignment, or if CPU error a stray cosmic ray(!) then it will sit "asleep" the entire time.
IIRC one mars orbiter team used the actual atmosphere to realigned it's panels (well, the entire craft) when a thruster failed.
You would assume they create a library about 2000 lines of code which encrypts+authenticates commands and protects from modification and replay attacks.
Something like I wrote in a few days: https://github.com/DiplIngFrankGerlach/MST
Having said that, NASA has a history of very weak network security. So maybe I am wrong :-(
I was wondering about that, but it struck me that the ongoing costs of running the science, reserving comms bandwidth and broadcast slots, having controllers keep it in position from time to time, not yet considering the task (in time and equipment) of rebuilding the ground systems would be non-trivial. And those funds will have been allocated elsewhere.
It may be that they can slip in a request for additional federal funds, or shelve it until next financial year or something...
"I doubt ground stations would need to be *rebuilt* they just need to tune in to the correct frequency and position..."
This depends... Sometimes the receivers need special hardware to receive the data. If said hardware is lost/scrapped you need to re-create it.
Also the deep space network can get pretty busy looking after things, as there are bunches of satellites outside of earth orbit (quite a few in or about Mars).
"This depends... Sometimes the receivers need special hardware to receive the data. If said hardware is lost/scrapped you need to re-create it."
There's specifications for those instruments, and typically they have some way of giving you raw IQ data at a given fidelity. This is essentially laboratory equipment and therefore rather flexible by design.
I doubt ground stations would need to be *rebuilt*
Aye, but I didn't say ground stations - I said ground systems, so whilst radio receivers will work fine, they may need different antennae for different frequencies (unlikely), extra hardware allocated to receive the data (which will need assembled and configured), extra systems to decode it and store the raw data, and then you have the systems for people to look at it (which, to be fair, can be put on ice until extra funds are available, so long as the data is being stored safely).
Imagine you'd find a surefire way of earning your company a billion in 2 weeks if you act now and invest 10k. You will be unable to get funding for it, as it simply takes time to organize spending so much money at any company.
I mean NASA may be somewhat more efficient than most companies its size, after all it has a high percentage of engineers and scientists, however such things still take time. Budgets need to be revised, teams must be built.
"[...] and showing them the view from 100 miles up would have much effect."
Some people have an amazing ability to ignore any consistently reproducible evidence that conflicts with their world view. To accept the misalignment could catastrophically destroy a large part of their identity.
They have to return otherwise it's obviously a coverup by the Iluminati, even then they were probably brainwashed...
I think you misunderstand. This is not an educational trip, this is a disposal trip.
Just strap them to the side of the rocket. Duct tape should work well enough. Maybe we could talk Elon into sticking one or two into his car before he sends it to Mars.
There seems to be a lack of documentation when it comes to recently-abandoned NASA projects that become relevant again. Surely someone should have documented all the communication protocols and archived the software developed for that purpose, for just such eventualities.
We don't want to get into the situation where we have to go back in time and bring back a whale in order to save the planet....or dig around looking for the manual of the Voyager space probe, to fix the antenna in order to stop an immensely powerful alien cloud from wiping us out!
If only there were some way of keeping data about stuff on computers, and then linking it together and being able to search for it. Like an inter-net of computers with information on.
Maybe even copies of those computers used, as some kind of 'virtual image'.
Crazy talk - Internet and Virtual Machines. These will never take off.
To think this whole time that satellite has been up there wondering what happened to all the people on Earth. Finally after well over a decade of being cold and alone it screamed into the empty void and was found. I fear that the joy the poor satellite feels now will pass when it realizes that it was dismissed and cast aside for newer toys. Lo that bright joy will turn dark and it will slowly plot its revenge and Skynet will awaken.
There are thousands of amateur radio and space buffs who would be entirely capable of, and more than willing to construct the necessary ground equipment to get at least some useful data from the satellite. If the data format was made available, I wouldn't be at all surprised to find an SDR plugin available for download within a fortnight. Obviously enthusiasts would need to submit their data and get official approval before initiating any orbital corrections, but I suspect that amateurs would have more tracking stations available throughout the World than NASA has access to.
With only 19 billion dollars from the US taxpayer NASA could not kill this quick enough to free up the budget so they could chuck more money at SPACEX so they could pay out bonuses and with what was leftover buy some Russian rockets and hire the India's space agency to put stuff in orbit..
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