Elektrod & Glacier
Elektrod Elektrod
Glacier Glacier
Glacier Glacier
I’ve been mulling over how we could engineer a fault‑tolerant network that can survive extreme temperatures and radiation, like for deep‑space probes. What do you think about designing a modular redundancy protocol for that?
Elektrod Elektrod
Sounds like a solid starting point, but you’ll need to layer the redundancy more carefully than just tripling the hardware. A triple modular redundancy scheme with a majority‑voting module can survive single‑event upsets, but if all three nodes sit in the same temperature zone a hot spot could kill them all at once. Keep spare modules in a thermally isolated cage, and use asynchronous voting so the clock skew doesn’t introduce another failure mode. Don’t forget radiation‑hardened firmware—self‑checking checksums or redundancy in the control logic itself will help you avoid latch‑ups. What kind of topology were you envisioning?
Glacier Glacier
I’d lean toward a tree‑shaped topology where each leaf node is a local cluster that feeds into a higher‑level coordinator. That way, if a hot spot wipes out one cluster, the others stay operational and can re‑route traffic. The asynchronous voting you mentioned would sit between the leaves and the coordinator, ensuring each cluster’s output is verified before propagation. I’ll design the firmware to double‑check critical paths and flag any latch‑up signatures before they affect the system. The key is keeping the thermal and radiation isolation separate for each cluster while still allowing them to communicate over a low‑power, low‑latency bus. Thoughts on the bus protocol?
Elektrod Elektrod
A low‑power, low‑latency bus that can survive cosmic rays has to be both simple and redundant. SpaceWire is the industry standard for deep‑space – it’s a serial, full‑duplex link, CRC‑protected, and has built‑in support for redundant paths. You can run two SpaceWire channels in parallel, each with its own driver and receiver, and let a small arbiter decide which channel to trust based on CRC and link‑health flags. If you want something even lighter, a radiation‑hardened CAN‑FD line is another option. It’s tolerant of bit‑flips thanks to its 64‑bit CRC, and you can hard‑wire a second CAN line for dual‑modular redundancy. The key is to keep the bus topology modular: each leaf cluster plugs into a local repeater, and the repeater feeds into the higher‑level coordinator over two parallel links. That way, if one link goes down due to a latch‑up or a hot spot, the other keeps the data flowing. Remember to include a watchdog on the bus firmware that checks the link health every few milliseconds and can trigger a switchover if one side shows abnormal error rates. And don’t forget a simple heartbeat packet so every node knows the bus is still alive. In short, pick a proven space‑grade serial protocol, duplicate the links, and add a lightweight arbiter that verifies CRCs and link health before passing traffic up the tree. It’s tedious, but it keeps the network from blowing up in a radiation storm.
Glacier Glacier
Sounds solid, especially the dual‑link arbiter idea. Let’s sketch the repeater firmware next and nail down the heartbeat timing. That should keep the bus healthy even if a single link dies.
Elektrod Elektrod
Sure, let’s lock the repeater logic into a simple state machine: listen on both links, if one CRC fails or the latency spikes above the threshold, raise a flag and route the data through the healthy path. For heartbeat, 1 ms ticks are overkill; 10–20 ms keeps the bus busy without wasting power. Put a 32‑bit counter in each packet so the other side can detect missed pulses and trigger a fail‑over. That’ll keep the bus humming even if one link goes belly up.