v0.2.0

Astro v0.2.0

This release completes the bidirectional CCSDS space communication stack — adding TC (telecommand) uplink protocols alongside the existing TM (telemetry) downlink, plus comprehensive documentation and conformance statements across all packages.

New Packages

• pkg/tcdl — TC Space Data Link Protocol (CCSDS 232.0-B-4)

  • TC Transfer Frames with variable length (up to 1024 bytes)
  • MAP sublayer with packet segmentation and reassembly
  • 64 Virtual Channels, Master Channel multiplexing, Physical Channel
  • Type-A (sequence-controlled) and Type-B (bypass/expedited) frame support
  • Frame Sequence Number N(S) for COP-1 integration

• pkg/cop — Communications Operation Procedure-1 (CCSDS 232.1-B-2)

  • FOP-1 (ground side): sliding window frame transmission with retransmission
  • FARM-1 (spacecraft side): window-based frame acceptance with lockout detection
  • CLCW encode/decode for return-link status reporting via TM OCF

• pkg/sdl — Shared Data Link Primitives

  • Generic channel buffers, multiplexers, and service interfaces
  • Eliminates code duplication between TM and TC implementations

• pkg/tcf — Time Code Formats (CCSDS 301.0-B-4)

  • CUC, CDS, CCS, and ASCII time code formats
  • CCSDS reference epoch (1958-01-01 TAI) with configurable custom epochs
  • Full encode/decode with Go time.Time integration

Enhancements

• pkg/tmsc — Reed-Solomon error correction

  • RS(255,223) and RS(255,239) codes over GF(2^8)
  • Berlekamp-Massey, Chien search, and Forney algorithm for full decode pipeline
  • Symbol interleaving at depths 1, 2, 3, 4, 5, and 8

• pkg/tmdl — TM Data Link improvements

  • Native multi-packet packing with FHP-based reassembly and loss resync
  • PhysicalChannel with weighted round-robin MC multiplexing
  • Frame gap detection via MC/VC count tracking
  • Thread safety, input validation, and robustness improvements

• pkg/spp — Space Packet Protocol improvements

  • Service type with Packet and Octet String services over io.ReadWriter
  • Per-APID sequence counting
  • CRC validation on decode and auto-compute on encode

Documentation

Every implemented package now has three documentation tiers:

Package	Guide	Reference	PICS Proforma
spp	Guide	Reference	PICS
tmdl	Guide	Reference	PICS
tmsc	Guide	Reference	PICS
tcdl	Guide	Reference	PICS
cop	Guide	Reference	PICS
tcf	Guide

Examples

• examples/downlink — TM downlink simulation (spacecraft to ground)
• examples/lossy-link — Packet transmission with frame loss and FHP-based recovery

Other Changes

• Refactored TMDL and TCDL to use shared sdl generic primitives
• Reorganized package files to align with protocol components
• Resolved all golangci-lint issues (errcheck, staticcheck, unused)
• Upgraded CI to golangci-lint v2.1

Full Changelog

v0.1.0...v0.2.0

v0.1.0

Astro v0.1.0

Initial release of Astro — a Go library for CCSDS space communication standards.

Packages

• pkg/spp — Space Packet Protocol (CCSDS 133.0-B-2)
  • SpacePacket struct with Encode() / Decode() round-trip support
  • Primary Header with APID, version, sequence flags, and packet length
  • Optional Secondary Header with SecondaryHeaderFlag
  • Packet Assembly and Extraction per CCSDS 4.2/4.3
  • Maximum packet length enforcement
  • TM and TC packet type support

Full Changelog

https://github.com/ravisuhag/astro/commits/v0.1.0