# Presentation: 852405

## Space InternetWhat’s Missing?

***Space Internet******What’s Missing?***

**James Rash **
**  ****- NASA/GSFC**
**Keith Hogie**
**Ed Criscuolo**
**Ron Parise   **
** ****- Computer Sciences **
**	****Corp**

## Overview

**What is Space Internet**
**Onboard Components**
**Ground Components**
**End-to-End Protocols & Applications**
**Summary**

- SIW 3 - Space Networking - What's Missing

- June 2003

## What is Space Internet

**End-to-end network connectivity using Internet technologies from spacecraft instruments and subsystems to ground systems, scientists, and other spacecraft**
**Communication systems based on layered protocol models used in the Internet**
- Break end-to-end communication into component areas the can be designed and built independent of other components
- Allow upgrading or replacing individual components without disturbing the rest of the communication system
**Mission design, development, testing and operation using standard distributed network concepts**

- SIW 3 - Space Networking - What's Missing

- June 2003

## Why Space Networking ?

**Design**
- Simpler/faster design using widely used, well known protocols
- Simpler ICDs since basic protocol design details already done
- Less risk using technologies that have been around for years and used by millions
- New types of operations concepts enabled with Internet communication  technology
**Development**
- Cheaper to use standard technology than design custom
- Internet community pays for most design and development costs
- Protocols and applications supported by vendors in operating systems
- High-rate communication equipment readily available from vendors
**Integration & Test**
- Many hardware and software diagnostic tools available for standard network environments
- Simpler subsystem interfaces using standard network technologies
- Much earlier integration and testing, find problems while they can be corrected easily
- Virtual spacecraft testing while subsystems are still under development across the country and around the world
- Reduced risk and better management visibility into ongoing development and test activities

- SIW 3 - Space Networking - What's Missing

- June 2003

## Why Space Networking ? 

**Operation**
- Automated operations using standard distributed processing concepts
- Protocols support spacecraft intercommunication if links are available
- Distributed processing across spacecraft
- Standard cross-support and interoperations among ground stations
- Long-term interoperability (current systems will work with future ones because the Internet needs that sort of interoperability)
**Maintenance**
- Easier equipment maint & upgrade using standard technologies
- Network equipment vendors do most maint& upgrades and users only pay a minimal annual fee, users don’t need large maintenance groups
- Fixes are better analyzed and tested in the Internet world due to the millions of users
**Security**
- Leverage huge investment in security being done for Internet community
- Continual upgrades in security protocols and mechanisms from Internet
- Extensive testing of security mechanisms on Internet

- SIW 3 - Space Networking - What's Missing

- June 2003

## End-to-End Network Architecture

**Router**

**Control**
**Center**

**Router**

**Bridge/Router**
**Mobile Routing**
**Data Link Framing**
**Encryption**
**Modulation/Coding**

**Router**

**Router**

**Spacecraft/Balloon**
**Field Site**

**Tracking **
**Station**

**Control Center**
**Data Distribution**

**PI**

**Dial-up**
**Scientist**

**Onboard LAN**
**Network Interface Cards**
**Onboard Hub/Switch**
**Network Data Storage**
**Network Time System**

**Data**
**Proc**

**Tracking**
**Station**

**Scientists**

**Instruments/**
** ****Subsystems**

**Security**

- E	Ethernet	F	Frame Relay	P	PPP
- L	LAN	W	WAN	M	Modem

**Router**

**Router**

**Spacecraft Monitoring / Commanding (SNMP, CMIS/CMIP,  MMS, etc.)**
** ****Data Delivery to Control Center (e.g. Email, FTP, MDP)**
**Distributed Integration & Testing**

**Scientist Interface with Instrument**
**Instrument Prepared Data Products**
**Data Delivery to Scientist (e.g. Email, FTP, MDP)**

**Virtual Instruments**
**Constellations of Satellites**

**E**

**L**

**IP**

**HDLC**

**E**

**L**

**IP**

**E**

**L**

**IP**

**F**

**W**

**E**

**L**

**IP**

**F**

**W**

**E**

**L**

**IP**

**E**

**L**

**IP**

**E**

**L**

**IP**

**F**

**W**

**P**

**M**

**IP**

**F**

**W**

**E**

**L**

**M**

**M**

**E**

**L**

**IP**

**P**

**M**

**IP**

**E**

**L**

**IP**

**1394**

**1394**

**HDLC**

**RF**

**1394**

**1394**

**IP**

**Eth**

**L**

**IP**

**Eth**

**L**

**IP**

**Eth**

**L**

**IP**

**Software bus**
**File systems**
**Time sync/distribution**

**Mod**

**Code**

**RF**

**Mod**

**Code**

**Network Time Reference**
**Network Data Storage**

**Mass**
**Store**

**Mass**
**Store**

**File Store & Forward**
**Automated Monitoring & Control**

**Mass**
**Store**

**Mass**
**Store**

- SIW 3 - Space Networking - What's Missing

- June 2003

## Space Components

**Primary challenge is developing standard network components for the challenging space environment**
- radiation 	- some radiation hardening needed in LEO orbits, higher and polar orbits need more
- power 	- spacecraft/remote systems operating with solar or battery power have limited power
- cooling 	- devices may require redesign for conduction cooling, relates to low-power
- thermal 	- devices must operate over extended thermal ranges and 	temperature cycling
- vibration 	- range/space equipment must survive launch and operational vibration
- weight 	- launching or flying more weight costs more money
- size 	- larger size results in more weight and associated launch issues
- reliability 	- devices must be highly reliable, replacement or repair is often impossible

- SIW 3 - Space Networking - What's Missing

- June 2003

## Space System Architecture 

**Onboard LANs among systems (e.g. Ethernet, ATM, 1394)**
**Onboard WAN interface for passing data to RF/Optical link**
**Upper layer protocols & applications onboard and end-to-end**

- SIW 3 - Space Networking - What's Missing

- June 2003

## Onboard LAN Component Status

- SIW 3 - Space Networking - What's Missing

- June 2003

## Onboard WAN Component Status

- SIW 3 - Space Networking - What's Missing

- June 2003

## Ground System Architecture

**Main issues are to identify modulation, FEC coding, encryption, and framing mechanisms that are widely available, efficient, and feasible for remote systems**
**Network time and file servers may support network time access and data storage/rate-buffering **
**Standard network technologies to the rest of the world**

- SIW 3 - Space Networking - What's Missing

- June 2003

## Ground Component Status

- SIW 3 - Space Networking - What's Missing

- June 2003

## Upper Layer Protocols & Applications

**IP provides an end-to-end datagram delivery service that supports upper layer “unreliable” and “reliable” data delivery**
**User Datagram Protocol (UDP) provides “unreliable” transport identical to legacy mechanisms like TDM and CCSDS framing**
- Works over both one-way and two-way links
- Can be used to support all possible communication needs of a mission
- All missions must use UDP for worst case error modes
**Transport Control Protocol (TCP) provides “reliable” byte stream transport but has problems with some space communication links**
- one-way links don’t work (e.g. blind commanding or TDRSS return-only links)
- high link bandwidth asymmetry (TCP can’t go much beyond 50:1 asymetry)
- high link error rate (TCP will keep trying until it gets all data through, may not be possible)
- long propagation delays (TCP feedback loop limits throughput with long delays)
**Many UDP applications work well in space (e.g. MDP, NTP, CFDP)**
**TCP applications can be used under proper conditions**

- SIW 3 - Space Networking - What's Missing

- June 2003

## E2E Protocols & Applications

- SIW 3 - Space Networking - What's Missing

- June 2003

## Summary

**End-to-end IP space networking is doable today and missions are currently using it (e.g. AlSat-1, CHIPSat, CANDOS)**
**Future missions are designing and building some of the missing pieces for space networking (e.g. GPM)**
**DoD Transformational Communication project is pushing development and deployment of future space networking**
**Vendors are developing additional components for space networking **
**The benefits of end-to-end networking with standard Internet technologies are being realized and will continue to drive further development **

**http://ipinspace.gsfc.nasa.gov/**

- SIW 3 - Space Networking - What's Missing

- June 2003