4 ms·

> Bus power consumption: 600w Sad to think my hacker news machine (PC) is using more power than an an intergalactic satellite.

fermienrico 8y ago
This is an absurd observation. Why is that surprising given that the satellite is in space and you have a giant powerplant connected to your PC and powering thousands of things in your city? More specifically, why is it saddening?
- craftyguy 8y ago
  Probably because they think the satellite is more capable of doing cool things than their PC, which is just displaying HN and (presumably) nothing more for them.
ptman 8y ago
is it really "between galaxies"?
- craftyguy 8y ago
  No. It'll never leave the Solar System unless it happens to surpass the escape velocity of the Solar System. Then, it'll never leave the galaxy unless it surpasses the Milky Way's escape velocity. That would require a tremendous amount of energy. IIRC the Milky Way's orbital escape velocity is something between 300-500km/s (depending on whether you leave the Solar System in a way to take advantage of its forward velocity through the Milky Way or not..)
  - bagels 8y ago
    I don't think large amounts of force is what you mean here, but energy instead. You can escape the galaxy if you apply a very small force over a very long time, or a larger force over a shorter time.
    - craftyguy 8y ago
      Ah yes, you are correct!
pier25 8y ago
Your PC is consuming 600W?
- yebyen 8y ago
  VR or bitcoin mining?
deleted 8y ago
[deleted]
Klinky 8y ago
How many watts to launch it into space? This probe needs wayyyyyyyyyy more than 600 watts to complete its mission. Most computers offer idle power savings. My quad core i5 uses like 15 watts while casually browsing the internet.
GlenTheMachine 8y ago
Spacecraft processors are many, many generations behind the desktop. A state of the art Maxwell flight rated processor runs at 800 MHz, single core, no vector acceleration, and will cost you $500,000 to $1,000,000.
- exikyut 8y ago
  Are there any functional or operational differences besides "it's going in a satellite so we get to charge you this much"? Radiation testing, maybe?
  - GlenTheMachine 8y ago
    There is virtually no functional difference between a flight qualified processor and a ground development board. The cost difference is due to the overall reliability requirement for flight parts, for one. If you lose your spacecraft processor you lose your spacecraft, which probably cost you a couple of hundred million dollars. So the yield rate for spacecraft CPUs is quite low, like single percentage low. The chips that fail the qual inspection become ground development units. In addition the manufacture, storage, and movement of each chip is very carefully managed and documented, which adds a surprising amount to the cost. This allows you to determine root causes in case of a failure, which then lets you understand whether other spacecraft using similar parts are in danger. Radiation tolerance is an important part of this, both in terms of lifetime exposure tolerance and in terms of single event upset susceptibility.
    - exikyut 8y ago
      Wow, thanks for the TIL. Suddenly I understand the fuss about the early processors (eg, the Forth ones) that went into spacecraft in the 70s and 80s. It wasn't just the architecture that was good, it was the electrical/physical design that was noteworthy (which, to excuse the terrible pun, the CPUs are still writing home about :D). Heh, I wonder how much the ground development boards cost? Probably way too much to find one affordably on eBay, say... Also - how do you figure out if a processor is going to last for ages? How do you test it?! Hmm, I get the impression some spacecraft probably have full failover capability as well. And now I wonder what systems use CPUs in lockstep _and_ have full independent failover...
axus 8y ago
Receiver-1 bitrate: 1000 bps Receiver-2 bitrate: 15.625 And that's pretty normal for command receivers.
anonytrary 8y ago
> intergalactic satellite You might mean interplanetary.
- TickleSteve 8y ago
  ...and not a satellite... except of the sun.

fermienrico 8y ago

This is an absurd observation. Why is that surprising given that the satellite is in space and you have a giant powerplant connected to your PC and powering thousands of things in your city? More specifically, why is it saddening?

craftyguy 8y ago
Probably because they think the satellite is more capable of doing cool things than their PC, which is just displaying HN and (presumably) nothing more for them.

ptman 8y ago

is it really "between galaxies"?

craftyguy 8y ago
No. It'll never leave the Solar System unless it happens to surpass the escape velocity of the Solar System. Then, it'll never leave the galaxy unless it surpasses the Milky Way's escape velocity. That would require a tremendous amount of energy. IIRC the Milky Way's orbital escape velocity is something between 300-500km/s (depending on whether you leave the Solar System in a way to take advantage of its forward velocity through the Milky Way or not..)
- bagels 8y ago
  I don't think large amounts of force is what you mean here, but energy instead. You can escape the galaxy if you apply a very small force over a very long time, or a larger force over a shorter time.
  - craftyguy 8y ago
    Ah yes, you are correct!

pier25 8y ago

Your PC is consuming 600W?

yebyen 8y ago
VR or bitcoin mining?

deleted 8y ago

[deleted]

Klinky 8y ago

How many watts to launch it into space? This probe needs wayyyyyyyyyy more than 600 watts to complete its mission. Most computers offer idle power savings. My quad core i5 uses like 15 watts while casually browsing the internet.

GlenTheMachine 8y ago

Spacecraft processors are many, many generations behind the desktop. A state of the art Maxwell flight rated processor runs at 800 MHz, single core, no vector acceleration, and will cost you $500,000 to $1,000,000.

exikyut 8y ago
Are there any functional or operational differences besides "it's going in a satellite so we get to charge you this much"? Radiation testing, maybe?
- GlenTheMachine 8y ago
  There is virtually no functional difference between a flight qualified processor and a ground development board. The cost difference is due to the overall reliability requirement for flight parts, for one. If you lose your spacecraft processor you lose your spacecraft, which probably cost you a couple of hundred million dollars. So the yield rate for spacecraft CPUs is quite low, like single percentage low. The chips that fail the qual inspection become ground development units. In addition the manufacture, storage, and movement of each chip is very carefully managed and documented, which adds a surprising amount to the cost. This allows you to determine root causes in case of a failure, which then lets you understand whether other spacecraft using similar parts are in danger. Radiation tolerance is an important part of this, both in terms of lifetime exposure tolerance and in terms of single event upset susceptibility.
  - exikyut 8y ago
    Wow, thanks for the TIL. Suddenly I understand the fuss about the early processors (eg, the Forth ones) that went into spacecraft in the 70s and 80s. It wasn't just the architecture that was good, it was the electrical/physical design that was noteworthy (which, to excuse the terrible pun, the CPUs are still writing home about :D). Heh, I wonder how much the ground development boards cost? Probably way too much to find one affordably on eBay, say... Also - how do you figure out if a processor is going to last for ages? How do you test it?! Hmm, I get the impression some spacecraft probably have full failover capability as well. And now I wonder what systems use CPUs in lockstep _and_ have full independent failover...

axus 8y ago

Receiver-1 bitrate: 1000 bps Receiver-2 bitrate: 15.625 And that's pretty normal for command receivers.

anonytrary 8y ago

> intergalactic satellite You might mean interplanetary.

TickleSteve 8y ago
...and not a satellite... except of the sun.