30 replies to this topic 1 votes

[Tyler R.]

Curiosity is attempting one of the most complex and dangerous maneuvers possible: Switching out its primary on-board computer for the identical, redundant fail-safe computer. It is hoped that the swap will restore Curiosity to full operational capability. The failure is due to some corrupted flash memory.

Curiosity’s RCEs is a single-board RAD750 computer — a radiation-hardened computer made by BAE that has a PowerPC 750 (G3) CPU clocked at around 200MHz, 256MB of RAM, 2GB of flash, and 256KB of EEPROM. It runs VXworks as its OS and managed with a Linux workstation.

http://www.extremete...l-functionality

[spudtrooper]

I believe they did something similar on the earlier rovers, I always love seeing these suckers pull through! (wasn't it opportunity that had bad flash and couldn't upload pictures at first?)

[Tyler R.]

spudtrooper, on 01 March 2013 - 18:32, said:

I believe they did something similar on the earlier rovers, I always love seeing these suckers pull through! (wasn't it opportunity that had bad flash and couldn't upload pictures at first?)

If I remember right, yes. I think it's so interesting that such a complex advanced piece of machinery has about the same specs as a G3 iBook.

[nekkidtruth]

Tyler R., on 01 March 2013 - 20:11, said:

If I remember right, yes. I think it's so interesting that such a complex advanced piece of machinery has about the same specs as a G3 iBook.

Seriously. We have smartphones with higher specs than Curiosity. It's actually a little sad.

[KevinN206]

nekkidtruth, on 01 March 2013 - 20:14, said:

Seriously. We have smartphones with higher specs than Curiosity. It's actually a little sad.

Radiation is difficult to deal with since you have so many different types (Total Ionizing Dose, Single Event Upset, Proton, Neutron, etc...) that can kill electronics.

[Anaron]

nekkidtruth, on 01 March 2013 - 20:14, said:

Seriously. We have smartphones with higher specs than Curiosity. It's actually a little sad.

It isn't sad when you consider the importance of such a computer. The rover doesn't need anything high-end. It needs something that's radiation-hardened (e.g. resistant to ionizing radiation) and something that is reliable. You wouldn't put a Ferrari engine in a car you use to drive to work everyday right?

[nekkidtruth]

KevinN206, on 01 March 2013 - 20:28, said:

Radiation is difficult to deal with since you have so many different types (Total Ionizing Dose, Single Event Upset, Proton, Neutron, etc...) that can kill electronics.

Oh I know. Doesn't make it any less sad. We're making water resistant dual-core phones (Xperia Z) and the Curiosity is floating up there with nearly decade old hardware, is the point. I'm sure there are things that can be done to improve the hardware we're sending up in space. Why wouldn't a dual or quad-core processor not be able to make it through space, but a processor essentially from 5 or more years ago? It's a bit ridiculous when you think about it!

Anaron, on 01 March 2013 - 20:30, said:

It isn't sad when you consider the importance of such a computer. The rover doesn't need anything high-end. It needs something that's radiation-hardened (e.g. resistant to ionizing radiation) and something that is reliable. You wouldn't put a Ferrari engine in a car you use to drive to work everyday right?

No, of course you wouldn't. However, I'd argue this is hardly even remotely close to the same thing. We're talking about exploring space. You don't believe that hardware capable of doing 10-20 times more would be infinitely more efficient? Using your analogy if we were to go into space today, you would rather have an engine built many years ago, or something built by today's standards and technology?

[BajiRav]

Anaron, on 01 March 2013 - 20:30, said:

You wouldn't put a Ferrari engine in a car you use to drive to work everyday right?

...I would.


(sorry, somebody had to say it)

nekkidtruth, on 01 March 2013 - 20:36, said:

Oh I know. Doesn't make it any less sad. We're making water resistant dual-core phones (Xperia Z) and the Curiosity is floating up there with nearly decade old hardware, is the point. I'm sure there are things that can be done to improve the hardware we're sending up in space. Why wouldn't a dual or quad-core processor not be able to make it through space, but a processor essentially from 5 or more years ago? It's a bit ridiculous when you think about it!



No, of course you wouldn't. However, I'd argue this is hardly even remotely close to the same thing. We're talking about exploring space. You don't believe that hardware capable of doing 10-20 times more would be infinitely more efficient? Using your analogy if we were to go into space today, you would rather have an engine built many years ago, or something built by today's standards and technology?

I think the Curiosity team explained why such a slow processor on their AMA. In short, the specs get finalized years before the actual mission and when Curiosity's planning started, that's what they had available.

[Dead'Soul]

nekkidtruth, on 01 March 2013 - 20:36, said:

Oh I know. Doesn't make it any less sad. We're making water resistant dual-core phones (Xperia Z) and the Curiosity is floating up there with nearly decade old hardware, is the point. I'm sure there are things that can be done to improve the hardware we're sending up in space. Why wouldn't a dual or quad-core processor not be able to make it through space, but a processor essentially from 5 or more years ago? It's a bit ridiculous when you think about it!



No, of course you wouldn't. However, I'd argue this is hardly even remotely close to the same thing. We're talking about exploring space. You don't believe that hardware capable of doing 10-20 times more would be infinitely more efficient? Using your analogy if we were to go into space today, you would rather have an engine built many years ago, or something built by today's standards and technology?

I think there must be a technical reason to choose that old system instead of our 8 cores.

[Astra.Xtreme]

nekkidtruth, on 01 March 2013 - 20:32, said:

Oh I know. Doesn't make it any less sad. We're making water resistant dual-core phones (Xperia Z) and the Curiosity is floating up there with nearly decade old hardware, is the point. I'm sure there are things that can be done to improve the hardware we're sending up in space. Why wouldn't a dual or quad-core processor not be able to make it through space, but a processor essentially from 5 or more years ago? It's a bit ridiculous when you think about it!

Power consumption, for one. Plus, as was already said, things like this are designed for a specific processing requirement and anything more than that is wasted resources. Your phone has million more functions than Curiosity, so of course it's going to have a million times more processing power. In the electronics world, a few MHz and a few KB, goes a long long way.

[neufuse]

nekkidtruth, on 01 March 2013 - 20:14, said:

Seriously. We have smartphones with higher specs than Curiosity. It's actually a little sad.

but the reason for it is radiation hardening, way way more testing in space like conditions, etc...

[Anaron]

nekkidtruth, on 01 March 2013 - 20:36, said:

No, of course you wouldn't. However, I'd argue this is hardly even remotely close to the same thing. We're talking about exploring space. You don't believe that hardware capable of doing 10-20 times more would be infinitely more efficient? Using your analogy if we were to go into space today, you would rather have an engine built many years ago, or something built by today's standards and technology?

I understand what you're saying and I agree, it makes sense to use powerful hardware to aid in the exploration of space and planets. However, it makes even more sense to use something that's reliable and stable. A computer hardware failure would kill a mission. Also, I'm sure they'd use something more powerful if they needed it. Anything beyond that would be a waste of power.

[nekkidtruth]

In response to all of the above responses directed towards me:

Don't get me wrong, I don't think an octo-core is necessary. I also understand the issues with power consumption and wasted resources. I don't expect them to use brand-spanking new, top of the line hardware. I just find it odd that it'sas behind as it is. Personally, I think they could have done better. Maybe next time?

[Dushmany]

Anaron, on 01 March 2013 - 20:30, said:

You wouldn't put a Ferrari engine in a car you use to drive to work everyday right?

I would, I'd have the only Ferrari powered Vauxhall Omega in existence, (I think)

[DocM]

The RAD computers are designed from go to be radiation resistant, largely by using larger circuit elements on the die at lower clock speeds. This allows it to continue even if one of the CPU circuit elements takes a direct hot by a cosmic ray (usually energetic protons) because the ions that event creates are few in a much larger current flow. Higher clock speeds and smaller elements would make these radiation induced ions statistically more significant. They also use error correction to a much greater degree than other computers.

SpaceX uses newer computer bits, but compensates for each board having a bit more radiation sensitivity by using them in polled arrays; if a board takes a hit and sends a result differing from the others it gets voted off the island and the others continue. Later they can reset it to see if it's let back in the game.

Tidbit: a couple of says ago a UK micro-satellite was orbited by an Indian launcher that is to test using a Nexus One smartphone as its main computer. Should get results soon.