Astro

Astro is an open-source Go library implementing CCSDS and ECSS space communication standards — the international protocols used by NASA, ESA, JAXA, and other space agencies for spacecraft communication and data systems.

Installation

Library

go get github.com/ravisuhag/astro

CLI

go install github.com/ravisuhag/astro@latest

Requires Go 1.26 or later.

CLI

The astro CLI provides commands for encoding, decoding, inspecting, and validating CCSDS data directly from the terminal.

# Encode a telemetry Space Packet
astro spp encode --apid 100 --type tm --data 68656c6c6f

# Inspect a packet with annotated hex dump
astro spp encode --apid 100 --type tm --data 68656c6c6f | astro spp inspect --input hex

# Validate a packet with CRC verification
astro spp encode --apid 100 --type tm --data a1b2c3d4 --crc | astro spp validate --input hex --crc

Command	Description	Docs
astro spp	Space Packet Protocol — encode, decode, inspect, validate, stream, gen	Reference
astro epp	Encapsulation Packet Protocol — encode, decode, inspect, validate, stream, gen	Reference
astro time	CCSDS Time Code Formats — encode, decode, inspect, now	Reference
astro tm	TM Transfer Frames — encode, decode, inspect, gaps, demux, gen	Reference
astro tc	TC Transfer Frames — encode, decode, inspect, gen	Reference
astro cadu	Channel Access Data Units — wrap, unwrap, inspect, sync, gen	Reference
astro cltu	Command Link Transmission Units — wrap, unwrap, inspect, gen	Reference
astro usdl	USLP Transfer Frames — encode, decode, inspect, gen	Reference
astro aos	AOS Transfer Frames — encode, decode, inspect, gen	Reference

Library Usage

import (
	"github.com/ravisuhag/astro/pkg/crc"
	"github.com/ravisuhag/astro/pkg/spp"
	"github.com/ravisuhag/astro/pkg/tmdl"
	"github.com/ravisuhag/astro/pkg/tmsc"
)

// Create and encode a telemetry packet
packet, _ := spp.NewTMPacket(123, []byte("temperature=22.5"))
encoded, _ := packet.Encode()

// Frame the packet with TM Data Link
frame, _ := tmdl.NewTMTransferFrame(0x1A, 1, encoded, nil, nil)
frameBytes, _ := frame.Encode()

// Wrap the frame as a Channel Access Data Unit (CADU)
cadu, _ := tmsc.NewCADU(frameBytes)
caduBytes, _ := cadu.Encode()

// Compute CRC for error detection
checksum := crc.CRC16CCITT(caduBytes)

Protocols

Protocol	Standard	Package	Docs
Space Packet and Transport
Space Packet Protocol	CCSDS 133.0-B-2	pkg/spp	Guide | CLI | PICS
Encapsulation Packet Protocol	CCSDS 133.1-B-3	pkg/epp	Reference | CLI | PICS
CCSDS File Delivery Protocol	CCSDS 727.0-B-5	pkg/cfdp	Guide | PICS
Licklider Transmission Protocol	CCSDS 734.1-B-1	pkg/ltp	Guide | PICS
Bundle Protocol	CCSDS 734.2-B-1	pkg/bp	Guide | PICS
Space Data Link
TM Space Data Link Protocol	CCSDS 132.0-B-3	pkg/tmdl	Guide | CLI | PICS
Proximity-1 Data Link Layer	CCSDS 211.0-B-6	pkg/pxdl	Guide | PICS
TC Space Data Link Protocol	CCSDS 232.0-B-4	pkg/tcdl	Guide | CLI | PICS
Communications Operation Procedure-1	CCSDS 232.1-B-2	pkg/cop	Guide | PICS
Space Data Link Security	CCSDS 355.0-B-2	pkg/sdls	Guide | PICS
AOS Space Data Link Protocol	CCSDS 732.0-B-4	pkg/aos	Guide | CLI | PICS
Unified Space Data Link Protocol	CCSDS 732.1-B-2	pkg/usdl	Guide | CLI | PICS
Synchronization and Channel Coding
TM Synchronization and Channel Coding	CCSDS 131.0-B-5	pkg/tmsc	Guide | CLI | PICS
Optical Communications Coding and Sync	CCSDS 142.0-B-1	pkg/ocsc	Guide | PICS
Proximity-1 Coding and Sync	CCSDS 211.2-B-3	pkg/pxsc	Guide | PICS
TC Synchronization and Channel Coding	CCSDS 231.0-B-4	pkg/tcsc	Guide | CLI | PICS
Space Link Extension
SLE Return All Frames	CCSDS 911.1-B-5	pkg/sle	Guide | PICS
SLE Return Channel Frames	CCSDS 911.2-B-4	pkg/sle	Guide | PICS
SLE Return Operational Control Fields	CCSDS 911.5-B-4	pkg/sle	Guide | PICS
SLE Forward CLTU	CCSDS 912.1-B-5	pkg/sle	Guide | PICS
SLE Internet Protocol for Transfer Services	CCSDS 913.1-B-2	pkg/sle	Guide | PICS
Data Compression
Lossless Data Compression	CCSDS 121.0-B-3	pkg/ldc	Guide | PICS
Image Data Compression	CCSDS 122.0-B-2
Spectral Preprocessing Transform	CCSDS 122.1-B-1
Low-Complexity Lossless Image Compression	CCSDS 123.0-B-2
Robust Compression of Housekeeping Data	CCSDS 124.0-B-1	pkg/rhc	Guide | PICS
Time
Time Code Formats	CCSDS 301.0-B-4	pkg/tcf	Guide
Packet Utilization
Packet Utilization Standard	ECSS-E-ST-70-41C	pkg/pus	Guide | PICS
Test and Operations Procedure Language	ECSS-E-ST-70-32C
Space Data Links — Telemetry Transfer Frame Protocol	ECSS-E-ST-50-03C	pkg/tmdl	Conformance
Mission Database
XML Telemetric and Command Exchange	XTCE 1.2 / CCSDS 660.1-G-2	pkg/xtce	Guide | Coverage
Shared Utilities
CRC-16-CCITT	CCSDS 130.0-G-3	pkg/crc

Contributing

Contributions are welcome. Each protocol listed above without a package is open for implementation. To get started:

1. Read the relevant CCSDS Blue Book or ECSS standard (linked in the table above).
2. Look at pkg/spp, pkg/tmdl, pkg/tmsc, or pkg/crc for the established patterns — struct design, encode/decode, validation, options, and tests.
3. Open an issue to discuss your approach before submitting a PR.

License

This project is licensed under the Apache 2.0 License.