Slashdot Mirror
Mars Rover Curiosity: Less Brainpower Than Apple's iPhone 5
Nerval's Lobster writes "To give the Mars Rover Curiosity the brains she needs to operate took 5 million lines of code. And while the Mars Science Laboratory team froze the code a year before the roaming laboratory landed on August 5, they kept sending software updates to the spacecraft during its 253-day, 352 million-mile flight. In its belly, Curiosity has two computers, a primary and a backup. Fun fact: Apple's iPhone 5 has more processing power than this one-eyed explorer. 'You're carrying more processing power in your pocket than Curiosity,' Ben Cichy, chief flight software engineer, told an audience at this year's MacWorld."
. . . how wasteful most commercial software packages are.
My sister opened a computer store in Hawaii. She sells C shells by the seashore.
... not enough power to run Angry Birds then?
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
Sure, the iPhone 5 may have more processing power... But I bet if you put that thing in space, the first cosmic ray that comes along will happily crash the OS. Game over.
Hardware in spaecraft has to be hardened big time against radiation. Off the shelf junk will NOT work. Just sayin'.
This is misleading. The rover has dozens of LRUs, all individually computing sensory input, crunching it, and sending it across the bus for the main computer to process. Yet it's only taking into account the main computer's processing power.
And yet, from my observations, all the iPhone is ever used for is cutting virtual rope and tweeting (low-res) pictures of food. Seems like quite a waste by comparison.
power use and battery life have to be dealt with as well.
Voyager 1/2 could run about 100K instructions per second, maybe less.
It's about the objective, not raw processing power.
And this is a fine opportunity! to pour some of my bile about the miserly state in which modern software is.
Looking for people to chat about multicopters, coding, music. skype: gtsiros
Nitpick with the summary: the rover is not 'one eyed'. It uses a bunch: http://mars.jpl.nasa.gov/msl/mission/rover/eyesandother/ That said, it does have that one big laser on its head: http://mars.jpl.nasa.gov/msl/mission/instruments/spectrometers/chemcam/ Robots on Mars with lasers. It doesn't get much better.
Saddle up: Riding with Robots
Curiosity's computer(s) can handle extreme cold and radiation of space while keeping radio communication for millions of miles, An iPhone is prone to overheat during normal use and has had trouble sending a radio signal though your hand.
I'll give Curiosity the gold medal any day.
Lets compare, shall we?
iPhone - sometimes flaky signal. Curiosity - working from millions of miles away. WIN Curiosity.
iPhone - works on Earth within range of cell towers. Curiosity - working on frakking Mars. WIN Curiosity.
iPhone - 1 day power life. Curiosity - radioactive power pack. WIN Curiosity.
iPhone - plays games, makes calls, takes pictures of girls making duck faces. Curiosity - scientifically explores and photographs another planet. WIN Curiosity.
iPhone - will shatter if you handle it wrong. Curiosity - dropped onto another world and still going. As designed. WIN Curiosity.
Curiosity, doing way the hell more, with way the hell less.
Way back in 2008 most of the hardware and software development was complete, so it should be compared to the original iPhone or the iPhone 3G.
Better double check your figures. Curiosity launched November of 2011. Just landed August of 2012.
Tut, tut! Don't assume! Go to Mars, turn her over, and check!
Devices prepped for the harsh environments will take longer to build than consumer devices, so the spec gets frozen sooner.
Plus, as long as it has enough horsepower, why mess with the design to upgrade it?
P.S. This is not really a new observation. Consider PhoneSat, the project to take an off-the-shelf Android phone and use it as the heart of a micro-satellite. Clearly the processing power is enough, plus they can use the camera, inertial sensors, and I guess even GPS. (I wonder if the GPS software can cope with orbital altitude?)
http://www.nasa.gov/offices/oct/home/PhoneSat.html
lf(1): it's like ls(1) but sorts filenames by extension, tersely
I've written an universal autopilot in 2007 that fits in 32K of eeprom. I say that not to brag, but to mean that these things are not unusual. Software on PLCs and so on is often very small -- it also has to be very good at not crashing. Fortunately that's all it has to be: nobody cares if the scroll bar doesn't glow when it's hit the end and so on, it just has to keep the power plant working :)
Liberty - Security - Laziness - Pick any two.
The cold fact is just that running a rich graphical UI, games, etc. can actually require more horsepower than some serious science stuff, even though the latter might seem more demanding.
'You're carrying more processing power in your pocket than Curiosity,' Ben Cichy, chief flight software engineer, told an audience at this year's MacWorld.
Taking guns away from the 99% gives the 1% 100% of the power.
And make sure you have more than one running at the same time. SpaceX uses non rad-hardened computers on Dragon, and in their last mission one computer had to reboot due to a radiation hit, but the system works fine since they have redundancy, this is explained in detail here. So no, hardware in spacecraft does not have to be hardened against radiation, and off the shelf junk will work. Of course this doesn't mean you can use iPhone on Mars rover since in Dragon's case it's a short mission and they're under the protection of Earth's magnetic field, it just means you need to design your system in a case by case basis and avoid over-generalization.
You're conflating serveral things..
Space Qualification doesn't have a lot to do with rad hardening. It's more about manufacturing processes, reliability, and testing to work over wide temps. That off the shelf computer probably won't work at -40C or +75C, while the processors in most spacecraft do. ISS or shuttle isn't a good example: it's basically an office environment: it even has *air*.
Rad hardening is something else. And the space processors *ARE* more successful at hardening than garden variety CPUs. Take a look at the LEON3FT SPARC core, for instance (Available commercially as the Atmel AT697 or the Aeroflex UT699, or you can burn it into an Actel RTAX2000, if you like). It has register paths that have error correction, etc. The demonstrated performance in a radiation environment *is* better than the non FT version.
There's single event upsets (SEU) aka "bit flips" which EDAC or parity works nicely for. Your laptop flipping a bit might not be a big deal.. most consumer software has enough bugs and things that you just restart and move on. If the processor controlling the rocket motors during entry descent and landing screws up it's a $2.5B hole in the ground. So internal registers in the space CPUs tend to be triple redundant or other upset mitigations.
But that's really not the big issues. There are things like Latch-Up.. that particle going through causes a latchup, and the resulting high current at a small location melts the chip. Oops, dead. There are latchup immune designs and processes, and there are latchup monitor/reset circuits, but it's not universal.
There's single event gate rupture (SEGR) which is where a MOSFET gate gets punctured because the normal charge on it is close to the failure level in normal operation, and the particle deposits just enough more to push it over the edge. Would you notice this on a modern CPU? Maybe it's in the microcode for calculating square root or something and you wouldn't for a long long time.
We use a lot of FPGAs in spacecraft these days.. If it's a xilinx, that particle can flip a configuration bit, and now you've just programmed your FPGA to have two outputs connected to the same "wire" and they have opposite values. Oops some dead gates now, or if it's bad enough dead chip.
ISS is a benign radiation environment.. about a Rad(Si) per year or so. There are *humans* on ISS, after all. After all 600 Rad will kill someone in days, 100 Rad will make them pretty sick. A typical design dose for a Mars mission might be 20kRad. For going to Jupiter, maybe a MegaRad?
But even in that benign radiation environment, a lot of COTS equipment will fail, and there's no way to predict, short of test. So they take all those COTS widgets and run them in a proton beam and figure out what the mean time til failure is. If it's long enough, you send it up to ISS and have at it. There's an awful lot of stuff that has "expected life on ISS" of something like 90-180 days. Google for the papers or look at the website http://www.klabs.org where a lot of this stuff is collected. 180 days on ISS is plenty if you're sending new stuff up on a regular basis. Even at $100k/kilo, that's pretty inexpensive to just send a new iPad up every few months if one dies.
If you're sending a billion bucks to Mars for 10 years, I think you might want something a bit better.
Cosmic rays actually interact very little either with the Earth's magnetosphere, atmosphere, or sillicon chips. They're going so fast that they don't hang around long enough to interact with atomic nuclei unless they score a direct hit. There really isn't much difference in cosmic ray exposure between the ground and, say, the surface of the Moon. The real problem is solar weather. The Sun regularly spits out particle blasts that would fry anything made of semiconductors. Those blasts are what power the aurorae. But those charged particles aren't going so fast so they're deflected by the magnetosphere (which is what protects the ISS) and they're also more readily absorbed by the atmosphere, which is why radiation levels at sea level are lower than they are in Denver. If you could get your iPhone and tablet safely out of the solar system, they would probably work fine on a generation starship.
Brackets contain world's first nanosig, highly magnified:[.]
Well you have to factor in the shipping cost...
"The Adobe Updater must update itself before it can check for updates. Would you like to update the Adobe Updater now?"
Indeed, I kept laughing at the MHz / GHz wars in the smartphone arena the last 18 months and couldn't help but nearly choke when I looked at solid integer / floating point performance and saw most of this wiz-bang 1 GHz Dual core stuff still getting stomped by stuff in the PII-450 / PIII-600 range (as I recall Atom started as more or less a process shrunk and trimmed down PIII with some of the Core series improvements and modularity grafted in).
It's a little weird to consider how much I wish there was a popular Atom x86 based Android in the US. Seriously, running Android and doing ARM emulation, they still stomp the ARM stuff. I wish Intel marketing would have some of their late 90's spirit and push themselves into the US smartphone industry with slogans like, "faster than ARM... at running ARM." Mind you, I actually mostly hate Intel. Nothing to inspire hatred like their GPU driver mess on Windows and Linux.
(From a year back) http://www.anandtech.com/show/5365/intels-medfield-atom-z2460-arrive-for-smartphones
I think you mean Opportunity, the twin of the Spirit rover that stopped working a while back. They were solar-powered versus the nuclear-powered Curiosity.
Here I am, brain the size of a mars rover, and they tell me to text 'OMG grl, wassup'....
---
The reason is that integer performance isn't worth wasting the silicone on in a mobile processor. It is already well beyond "good enough". What does count is power consumption, where ARM is still in another league to x86, and in floating point operations. ARM has NEON SIMD instructions for that and they are pretty good for audio/video processing and games. In addition a lot of stuff is handed off to the GPU now anyway (transform and lighting, video decoding) which is always going to be far more efficient.
There is a reason there are not many x86 mobile devices. Atom is more expensive and hard to get good battery life from. Raw performance is good but having four low power cores and a good GPU is better for providing a smooth user experience and mobile games.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Indeed, I kept laughing at the MHz / GHz wars in the smartphone arena the last 18 months and couldn't help but nearly choke when I looked at solid integer / floating point performance and saw most of this wiz-bang 1 GHz Dual core stuff still getting stomped by stuff in the PII-450 / PIII-600 range (as I recall Atom started as more or less a process shrunk and trimmed down PIII with some of the Core series improvements and modularity grafted in).
Atom is not a PIII. It is closer to the original P54C (Pentium), but not very close (Larrabee is far closer, but still heavily modified). The main argument for this is that the PIII, as a descendent of the Pentium Pro, was out of order. All released Atoms so far are in-order, but they are on the other hand both wider, far more well-cached and better at branch prediction than the original Pentium. Basically, they do a lot to bring down the latencies that can arise from an in-order architecture.
Mars rover: lasts for years. iPhone barely makes it through the day.
Or how about speed? Mars rover several meters a day. iPhone, just sits there.
User upgrades in the field? Mars rover: zero. iPhone: zero.
Yeah yeah, you have more computing power in your pocket then in NASA machine. That was a fun stat for voyager news briefings. A decade ago. It is not funny anymore, it is just sad and a sign the reporter in question has no idea about tech. This stuff is for morning tv.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
The A6 and A6X are in the same speed range as the high-end G5's and low end CoreSolos (and a few CoreDuos) from 6 years ago. And yes, it is very impressive, especially when you consider the power, heat, size, cooling, and price differences between them. It also makes you wonder about the future, in 6 years will we have Sandy Bridge i5 level performance in our phones?
It's truly phenomenal. And then you realize that this power, heat, size, price, cooling savings also includes an impressive GPU as well.
Sure, there are various sorts of things to consider beyond benchmarks and such, but it's quite impressive no matter how you look at it. And even if the specific details for the story in question, PPC 750 (I'm assuming that because you are referencing it, that's what's in Curiosity), vs an A6 SoC isn't a fair fight, I do think most people (including most Slashdot nerds) would either be surprised, or at least find it an interesting tidbit, that the processing power of the solar system's most advanced robot is dwarfed by an everyday consumer phone used by millions. Even those of us who understand the process through which technology is tested, selected, hardened, and programmed for, how reliability and consistency is preferred over raw performance, how embedded processors aren't taxed in the same way desktop, or even mobile, systems are taxed, etc., how even we can see the unique and notable dynamic here.
The impressive part isn't the speed, it's the fact the A6 in the iPhone 5 is running with the same 3.7v 1400mah battery in the original 412mhz iPhone. That's like throwing the supercharged V8 in your car but still getting 50mpg Prius numbers.
my karma will be here long after I'm gone