61 points by p0u4a 4 days ago | 8 comments
dfox 5 minutes ago
> running identical software on multiple computer systems is the name of the software-architecture game

In the railway signalling industry (which for historically obvious reasons is obsessed with reliability) there even is a pattern of running different software implementing the same specification, written by different team, running on a different RTOS and different CPU architecture.

KurSix 13 minutes ago
The contrast with modern software development is striking. Today we often rely on fast iteration and patching problems in production. Spacecraft software is the opposite
somat 1 hour ago
"From the dawn of the Space Age through the present, NASA has relied on resilient software running on redundant hardware to make up for physical defects, wear and tear, sudden failures, or even the effects of cosmic rays on equipment."

An interesting case study in this domain is to compare the Saturn V Launch Vehicle Digital Computer with the Apollo Guidance Computer

Now the LVDC, that was a real flight computer, triply redundant, every stage in the processing pipeline had to be vote confirmed, the works.

https://en.wikipedia.org/wiki/Launch_Vehicle_Digital_Compute...

Compare the AGC, with no redundancy. a toy by comparison. But the AGC was much faster and lighter so they just shipped two of them(three if you count the one in the lunar module) and made sure it was really good at restarting fast.

There is a lesson to be learned here but I am not sure what it is. Worse is better? Can not fail vs fail gracefully?

KurSix 11 minutes ago
I think the lesson is that redundancy can exist at different layers
throwup238 23 minutes ago
> There is a lesson to be learned here but I am not sure what it is.

Restart your Claude Code sessions as often as possible

baud147258 1 hour ago
> Worse is better?

Maybe if you know what the tradeoffs are and are ready to deal with the deficiencies (by rebooting fast). And didn't they had issues with the lunar module Guidance Computer on the first moon landing?

thomascountz 2 hours ago
OT: I really enjoyed The Increment when it was first being released. It felt like the first software engineering practitioner's publication and introduced me to a lot of new people to follow.
throwaradfy5745 6 hours ago
How would these considerations affect Musk's space cloud ?
rogerrogerr 6 hours ago
Starlink very likely leans toward “many cheaper satellites that may fail” instead of “fewer expensive satellites that are less likely to fail”

Their advantage in the satellite-internet industry is that they can launch stuff fast and cheap; very likely this drives different tradeoff decisions than the regime this article talks about.

phanarch 28 minutes ago
The Starlink tangent misses something important about why software reliability in satellite systems is categorically different from hardware reliability.
Panzerschrek 4 hours ago
Having thousands of satellites also allows finding more software bugs, so that in the reality they can be more reliable compared to NASA-style probes (when each one has its unique software).
gostsamo 5 hours ago
The same way it will affect the incoming mission to the center of the galaxy. The space cloud is much more related to the incoming SpaceX ipo than to any phenomena of the physical or computing universes. Thermodynamics says "no".
8 hours ago
gnabgib 4 days ago
(2020)
adampunk 8 hours ago
Do not attempt to adjust your television. We control the horizontal. We control the vertical.

We know Glenn is loquacious.