Slashdot Mirror
Upgrading Software From 350 Million Miles Away
CWmike writes "Picture doing a remote software upgrade. Now picture doing it when the machine you're upgrading is a robotic rover sitting 350 million miles away, on the surface of Mars. That's what a team of programmers and engineers at NASA are dealing with as they get ready to download a new version of the flight software on the Mars rover Curiosity, which landed safely on the Red Planet earlier this week. 'We need to take a whole series of steps to make that software active. You have to imagine that if something goes wrong with this, it could be the last time you hear from the rover,' said Steve Scandore, a senior flight software engineer at NASA's Jet Propulsion Laboratory. 'It has to work,' he told Computerworld. 'You don't' want to be known as the guy doing the last activity on the rover before you lose contact.'"
The spacecraft TRAVELLED 350 million miles to get there, but as of tonight, Mars is only about 157.5 million miles from Earth.
Exactly. That's how it's done in the telecomms world (infrastructure, not terminals). Typically the new software is given three attempts to boot, and if it doesn't acknowledge that it's fully booted after three attempts, the bootloader falls back to the previous version of the software. Of course, things get tricker if you need to update the bootloader, but those should be very rare situations. However, they in turn can be handled a similar way (typically there's a 3-stage boot, the initial being a ROM bootstrap, then your bootloader, then the OS which you'll want to change).
Also FatPhil on SoylentNews, id 863
Computers: The two identical on-board rover computers, called "Rover Compute Element" (RCE), contain radiation hardened memory to tolerate the extreme radiation from space and to safeguard against power-off cycles. Each computer's memory includes 256 kB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory.[22] This compares to 3 MB of EEPROM, 128 MB of DRAM, and 256 MB of flash memory used in the Mars Exploration Rovers.[23]
The RCE computers use the RAD750 CPU, which is a successor to the RAD6000 CPU used in the Mars Exploration Rovers.[24][25] The RAD750 CPU is capable of up to 400 MIPS, while the RAD6000 CPU is capable of up to 35 MIPS.[26][27] Of the two on-board computers, one is configured as backup, and will take over in the event of problems with the main computer.[22]
http://en.wikipedia.org/wiki/Curiosity_rover#Specifications
Data transfer speeds between Curiosity and each orbiter may reach 2 Mbit/s and 256 kbit/s, respectively, but each orbiter is only able to communicate with Curiosity for about eight minutes per day
When you have little bandwidth, better get it right the first time.
The point of the exercise is to replace the no longer needed flight software with software it can use to better perform it's tasks while on Mars.
We don't believe in radical loony monotheistic religions from the middle east -- we're Christians.
99% of brickings are the result of people doing stuff that the manufacturer did not intend for you to do, on devices where important design details were hidden for commercial reasons.
This is unlikely (one would hope) to be the case here.
That is probably why a team of 100 software engineers issues about 1000 commands per day for the rover. My guess is a lot of the work is triple checking everything before they upload an update. There is just no room for error in this situation.
Tomorrow is another day...
The radiation this thing emits is NOTHING compared to the solar and cosmic radiation it would experience both in transit and on Mars. Putting everything in a metal box only helps so much, you still need specifically designed electronics which can handle the odd bit of radiation without dying. Even with a thick metal box you can't run an i7 on Mars, or not for very long at least. Your standard DDR3 isn't going to work either, or your standard EEPROM.
The other thing to remember is that although this project is extremely important, they're still not going to throw more capabilities in than they need, because that is more that can go wrong. For a remote sensing platform, the amount of EEPROM isn't that important - you just need enough to hold your communication protocols, some basic reaction-to-obstacle algorithms and the motor control code. You aren't going to be pulling massive libraries in. The emphasis is on making it as simple as possible, so that there is less chance for bugs to creep in. Those extra MIPS will come in handy for the navigation and onboard image processing, and the flash for storing interesting info until you can upload, so those are what they have upgraded the most.
Help I am stuck in a signature factory!
It's not a linear relationship since you need additional propellant to move the additional propellant you needed for the extra payload
CLI paste? paste.pr0.tips!