# Presentation: 391492

## Innovative Uses for TDRSS:The South Pole TDRSS Relay (SPTR)

**Innovative Uses for TDRSS:****The South Pole TDRSS Relay ****(SPTR)**

- Technology Forum
- February 17, 1998

- Dave Israel
- Code 567.3

## SPTR Overview

- The South Pole TDRSS Relay was installed in December 1997.
- It was funded as a Proof of Concept to prove the following:
- TDRS-1 can support the South Pole
- TDRSS can provide a high speed IP connection
- TDRSS can provide a high speed file transfer capability

## TDRS-1 Visibility from the South Pole

- TDRS-1’s high inclination (>9.5 degrees) makes the satellite in view of the South Pole for over 3.5 hours.
- This time period will increase over time.
- TDRSS capabilities are much greater than the capabilities of any other satellites visible from the South Pole.

## SPTR Design Goals

- Demonstrate 50 Mbps return link
- Install a 2 - 10 Mbps file transfer capability
- Install an 1.024 Mbps bi-directional IP link
- Prove operations in South Pole environment

## SPTR Results 

- SPTR Results

- 50 Mbps KSAR from the Pole was successfully tested in December.
- S-Band IP and K-Band File Transfer services were declared operational on 1/5/98.
- Since 1/6/98
- 592 Mbytes on S-Band to the Pole
- 442 Mbytes on S-Band from the Pole
- 17 Gbytes on K-Band from the Pole

## What’s Innovative about SPTR?	

- What’s Innovative about SPTR?

- First time true IP data was transferred by TDRSS to/from the Internet.
- First time users were able to FTP their data from WSC
- User RF and data system almost entirely COTS

## SPTR IP Connection

## SPTR File Transfer Service

## SPTR Additions to White Sands

## SPTR Additions to White Sands (cont’d)

- New Internet connection into WSC (~1 Mbps)
- File Server for K-Band transfers & FTP
- Router connects local LAN to Internet and TDRSS link
- TDRSS Data Interface provides coding, scrambling, and de-scrambling
- Duplicate equipment at both White Sands Terminals

## SPTR South Pole Hardware

## SPTR South Pole Hardware (cont’d)

**K-Band System**
- File Server
- Convolutional Encoder
- BPSK Modulator
- 20W TWT
- 4 foot antenna
**S-Band System**
- Router
- Satellite Modem
- Up/Downconverter
- 10W PA
- 4 foot antenna

## SPTR South Pole Hardware (cont’d)

## Advantages of Direct IP TDRSS Link

- No additional data lines required - access through the Internet
- Any IP software can be used
- Make full use of commercial standards and new developments

## Disadvantages of Direct IP Link

- Two-way connection required
- Geosat delay effects
- Data performance better than 1e-5 BER required
- Access through the Internet

## Possible Future Users

- Remote Field Camps (Aruba Eclipse support, Antarctica)
- Balloons
- Planes
- University Explorers

## Aruba Eclipse Support

- Full solar eclipse February 26, 1998
- NASA support requested by the Exploratorium for Internet connectivity to Aruba for eclipse broadcast
- Only changes required at WSC are router updates
- Functional duplicate of SPTR S-band system put together for the Aruba side of the link

## Eclipse Support Hardware(Field Camp Scenario)

- Eclipse Support Hardware(Field Camp Scenario)

## Potential Follow-On Activities

- Assemble a permanent “Field Camp” rack
- Experiment with methods to optimize TCP/IP performance
- Minimize user system size/power for remote operations and possible flight

## Summary

- The basic infrastructure is now in WSC which will allow future tests and missions to use the Internet and Internet standards for data handling and transmissions.
- We’re looking for users/experimenters
- More information
- http://www530.gsfc.nasa.gov/SPTR/
- http://www.exploratorium.edu/eclipse
- e-mail:  dave.israel@gsfc.nasa.gov