# Presentation: 116799

## SNAP Mission OperationsWBS 3.1

**Dr. Manfred Bester**
**Space Sciences Laboratory**
**University of California at Berkeley**
**July 2002**

## Ground Data System Requirements

**Communicate with Spacecraft**
**Maintain Reliable Link Margin on Forward and Return Link**
**Monitor Spacecraft Health and Safety**
**Housekeeping Functions, Data Trending**
**Provide Spacecraft Command Loads**
**Schedule Attitude Maneuvers, Observations and Data Dumps**
**Maintain Instruments, Spacecraft Bus and Flight Software**
**Retrieve and Archive Science Data (3.5 Tbits / Orbit)**
**Process Data and Provide Access to Science Community**
**Alert Operations Personnel in Case of Anomalies**
**Support Reliable, Autonomous Operations**

## Mission Operations Tasks

**SNAP Mission Operations Tasks**
**Maneuver Planning and Execution During L&EO**
**State-of-health Monitoring and Data Trending**
**Control of Science Instruments**
**Doppler Tracking **
**Orbit Determination**
**Generation of Mission Planning Products**
**Ground Contact Scheduling**
**Command Load Generation**
**Target Acquisition and Attitude Control**
**Support of Daily Low-rate Telemetry and Command Passes**
**Recovery of High-rate Science Data Once Every 3 Days**

## Mission Operations Concept

**Launch and Mission Orbit**
**Launch by Boeing Delta IV**
**Orbit 153,000 x 10,000 km at 26.5° Inclination**
**Coplanar with Lunar Orbit to Minimize Perturbations**
**3-Day Period**
**Operations Centers**
**Mission Operations Center at UCB/SSL**
**Science Operations Center at LBNL**
**Telemetry and Command**
**Berkeley Ground Station as Prime Facility**
**NASA/DSN as Back-up**
**S-Band for Command and Engineering Telemetry**
**Ka-Band for High-Rate Science Telemetry **

## SNAP Mission Orbit

## SNAP Ground Data System

## Special Network Interfaces

**Special Network Interfaces**
**Secure Control Network**
**Dedicated Workstations on Isolated Subnet**
**Secure Link to NASA/DSN for Back-up Commanding**
**Firewall Protection**
**High-rate Interface**
**Fiber-optic Link Between SSL and LBNL for High-rate Data Transfer**

## Infrastructure and Heritage at SSL

**Existing Infrastructure at SSL**
**Joint Mission and Science Operations Center**
**11-m S-Band Ground Station for Tracking, Telemetry and Commanding**
**Active Flight Operations**
**Missions Supported at SSL**
**EUVE****	****	****MOC, SOC (Mission Ended in 2002)**
**FAST****	****	****MOC, SOC, TDA & CMD (On Orbit)**
**RHESSI****	****	****MOC, SOC, TDA & CMD (On Orbit)**
**IMAGE****	****	****TDA (On Orbit)**
**CHIPSAT****	****	****MOC, SOC, TDA & CMD (To Be Launched)**

## UCB Mission Operations Center

- BGS Antenna, Equipment Racks and FOT Workstations at the UCB Mission Operations Center

## Berkeley Ground Station

**Technical Highlights**
**Antenna**
- 	**Model 300 Pedestal (L-3 Com, EMP Systems)**
**	****11-m Parabolic Reflector with Prime Focus Feed**
**	****Three Axis Drive System:**
**	****Azimuth / Elevation / Cross-Elevation**
**	****Autotracking with Conical Scan System**
**RF Systems**
- 	**S-Band Telemetry and Command Capabilities**
**	****Receive Polarization Diversity **
**	****Figure of Merit (G/T) > 24.5 dB/K at 5**** ****o Elevation**
**	****Transmit Power 100 W, EIRP > 63 dBW**
**Data Processing**
- 	**Dual CCSDS Frontend Processors Up to 10 Mbps**
**	****Telemetry Data Routing by Virtual Channel IDs**
**	****Command Forwarding**
**Construction**
**	****Total Construction Time 18 Months in 1998/1999**
**	****Costs Including Site Development  $2.5M**

## UCB Mission Operations Center

## UCB Mission Operations Environment

**Mission Operations Functions Performed at UCB**
**Flight Dynamics**
**Mission Planning**
**Spacecraft Command and Control**
**Ground Station Operations**
**Archiving of Engineering Data**
**SNAP Operations Based on FAST and RHESSI Heritage**
**SNAP Work Space Will Follow FAST and RHESSI Model**
**Identical Software Tools: SatTrack, ITOS, MPS, SERS**
**Software Development Required for Interfacing with SOC at LBNL**
**High Degree of Integration and Automation**
**SNAP Will Benefit from Previous Integration Work**
**GDS Concept Tested Extensively with FAST, RHESSI & Missions of Opportunity**

## Typical ITOS Display Pages

**Typical ITOS Display Pages**

## SNAP BGS Pass Coverage

**Station Access:**
- Available Pass Duration
- 5.0 h @ Range < 60,000 km
- Once Every 3 Days
**Required Access:**
- 3.3 h @ 300 Mbps
- Once Every 3 Days
**Link Margin:**
- Telemetry:    4.5 dB  (Ka-Band)
- Command:  13.5 dB  (S-Band)
**Station Mask:**
- Terrain, Vegetation and
- Buildings
- Trace represents a typical perigee pass with link margin larger than 6 dB (blue).

- Downlink schedules will be based on dynamic link access rather than pure line-of-sight geometry.

## Spacecraft Telecom System

**S-Band:**
**STDN Transponder (2)**
**5W RF Output**
**Omni Antennas**
**Ka-Band:**
**High-rate Telemetry Transmitter (2)**
**5W RF Output**
**Articulated Dish Antennas (3)**
** **

## High-Rate Telemetry Link Budget

| Spacecraft |  |
| --- | --- |
|     Frequency (Ka-Band) | 32,000 MHz |
|     Spacecraft Transmit Power  | 5 W |
|     Spacecraft Antenna Gain (50-cm Aperture) | 42.6 dB |
|     Spacecraft EIRP | 47.5 dBW |
| Transmission Medium |  |
|     Range | 60,000 km |
|     Atmospheric, Pointing & Polarization Losses | 4.2 dB |
| Ground Station |  |
|     System Temperature | 713.0 K |
|     Receiver G/T (10-m Aperture) | 40.0 dB/K  |
| Data Rates and Modulation |  |
|     Data Rate | 300,000 kbps |
|     Modulation | QPSK |
|     Coding | Reed-Solomon |
|     Bit Error Rate | 1.0e-6 |
|     Predicted Eb/No | 12.1 dB |
| Link Margin |  |
|     Predicted Link Margin | 4.5 dB |

## Low-Rate Telemetry Link Budget

| Spacecraft |  |
| --- | --- |
|     Frequency (S-Band) | 2,250 MHz |
|     Spacecraft Transmit Power  | 5 W |
|     Spacecraft Antenna Gain (Omni Antenna) | 0 dB |
|     Spacecraft EIRP | 5.0 dBW |
| Transmission Medium |  |
|     Range | 165,000 km |
|     Atmospheric, Pointing & Polarization Losses | 1.2 dB |
| Ground Station |  |
|     System Temperature | 200.0 K |
|     Receiver G/T (10-m Aperture) | 22.5 dB/K  |
| Data Rates and Modulation |  |
|     Data Rate | 10 kbps |
|     Modulation | BPSK |
|     Coding | Reed-Solomon |
|     Bit Error Rate | 1.0e-6 |
|     Predicted Eb/No | 11.5 dB |
| Link Margin |  |
|     Predicted Link Margin | 3.9 dB |

## Command Link Budget

| Ground Station |  |
| --- | --- |
|     Frequency (S-Band) | 2,040 MHz |
|     Ground Transmit Power  | 200 W |
|     Ground Antenna Gain (10-m Aperture) | 0 dB |
|     Ground EIRP | 65.2 dBW |
| Transmission Medium |  |
|     Range | 165,000 km |
|     Atmospheric, Pointing & Polarization Losses | 0.5 dB |
| Spacecraft |  |
|     System Temperature | 1330.0 K |
|     Receiver G/T (Omni Antenna) | -34.2 dB/K  |
| Data Rates and Modulation |  |
|     Data Rate | 2 kbps |
|     Modulation (16 kHz Subcarrier) | BPSK/PM |
|     Coding | None |
|     Bit Error Rate | 1.0e-7 |
|     Predicted Eb/No | 23.2 dB |
| Link Margin |  |
|     Predicted Link Margin | 7.7 dB |

## Ka-Band Technology

**Current State-of-the-Art**
**Push to Higher Frequencies Since Bandwidth Limited at S/X-Band**
**Advanced Communications Technology Satellite (ACTS) on Orbit**
**Test Bed for Ka-Band Links**
**New TDRSS H/I/J Have Ka-Band Links Up To 300 Mbps**
**High-bandwidth Links Already Exist at Ku-Band for TV/Video**
**Bit Synchronizers and CCSDS Processors Exist for 520 Mbps**
**Future Systems**
**High-rate Ka-Band Transmitters Under Development**
**Wideband Gapfiller Satellite Constellation (WGS) (DoD/Boeing)**
**Upgrade Plans for Corresponding Ground Systems in Progress**

## NASA/DSN Roadmap

- Reference: NASA’s Deep Space Telecommunications Roadmap, http://tmod.jpl.nasa.gov/technology

## Ka-Band Transponder

- Small Deep Space Transponder (General Dynamics)
- 5 W, Up to 8 Mbps at Ka-Band

- State-of-the-Art Ka-Band Technology

## Ka-Band Ground Antennas

- 12-m Prototype Antenna for NRAO’s 64-Element Atacama Large Millimeter Array (ALMA) Presently Installed at VLA Site in New Mexico

**Manufacturer:**
**VertexRSI, Santa Clara, CA**
**Costs for Prototype:  $6.2M**
**Aperture Diameter:  12 m**
**Surface Accuracy:     25 ****μ****m r.m.s.**
**Max. Frequency:       600 GHz**
**Pointing Accuracy:    0.6 arcsec**

## Costs and Schedule

**Operations Costs**
**Based on EUVE / FAST / RHESSI Model**
**Cost Effective Approach**
**Mission Operations, Ground Station and Flight Dynamics Integrated Into One Coherent, Highly Automated Facility**
**Phase-in Operations Team Gradually**
**Operations Schedule**
**Develop SNAP MOC**
**Workspace Configuration & Procedure Development**
**End-to-end Testing**
**FOT Training**

## Risk Mitigation

**Operational Redundancy**
**Dual Strings in Equipment Where Practical, Back-up Power**
**Multiple Workstations for Telemetry and Command Support**
**Conduct Interface Tests at Various Stages**
**RF and Data Compatibility Tests**
**End-to-end Data Flows**
**Begin FOT Training Early in the Program**
**Participate as Test Conductors**
**Remote ITOS Displays at Spacecraft Contractor Site**
**Tie In Subsystem Engineers for Anomaly Resolution**

## Summary

**Heritage Exists at SSL for Mission Operations, Including Tracking, Data Acquisition and Flight Dynamics**
**EUVE, FAST, RHESSI, IMAGE**
**Study Hardware Upgrades Needed to Meet SNAP Mission Requirements**
**Ka-Band Capability**
**Support of High Data Rate**
**Study and Develop Data Flow Interface with LBNL**
**Forwarding of Telemetry Data**
**Ingest and Processing of Observation Schedules**