Parsimoni’s pure-OCaml CCSDS protocol stack, Borealis, booted on DPhi Space’s ClusterGate-2 in April 2026 with post-quantum OTAR and end-to-end encryption.
Key Takeaways
Borealis runs on an Arm Cortex-A53 SoC (4 GB RAM) as a FROM-scratch Docker image (5-10 MB), treating DPhi’s filesystem API as a delay-tolerant DTN network via BPv7 bundles.
BPSec wraps every bundle: one extension block encrypts payload, one authenticates it; sequence numbers block replays, keeping the satellite operator blind to content.
Post-quantum ML-DSA-65 signing keys rotate via OTAR without reflashing; this is claimed as the first public in-orbit demo of post-quantum OTAR, mandated by NASA-STD-1006A for long missions.
OxCaml’s exclave_ stack_ annotations drop p99.9 dispatch latency from 29 ns to 9 ns and eliminate GC pressure entirely (394 minor GCs to zero over 25 million packets).
The master key has no rotation path once in orbit; if lost, the stack is unreachable – the acknowledged failure mode for hardware lacking a TPM or secure element.
Hacker News Comment Review
Commenters debated whether CCSDS’s complexity forces too much from-scratch work; the author concedes TLS would be preferable but argues no good open-source full CCSDS/SDLS stack exists, making transition hard.
The GC-with-opt-out pattern drew broad interest: parallels were drawn to .NET Span/Memory and Java HFT heap pre-allocation, with the key insight that OxCaml’s type system enforces stack-boundedness at compile time rather than relying on discipline.
KC Sivaramakrishnan (kcsrk, referenced in the article) noted that LLM agents produce surprisingly correct OxCaml code despite sparse training data, suggesting OxCaml’s strong types act as testable oracles for AI-generated code.
Notable Comments
@rho_soul_kg_m3: Claims OCaml was first flown in LEO in 2016 on GHGSat-D with symmetric-key encryption of payload data; a reply confirms GHGSat’s constellation is now 16 satellites, still mostly OCaml.
@noelwelsh: Frames OxCaml as a direct alternative to Rust and Zig: “safety and ergonomics together,” pointing to a personal introduction post.
