Calhoun: The NPS Institutional Archive

Faculty and Researcher Publications Faculty and Researcher Publications

2005-07-15

NPSAT1, Spacecraft Architecture and

Technology Demonstration Satellite

Brief / July 2005

Space Systems Academic Group

Monterey, California; Naval Postgraduate School

http://hdl.handle.net/10945/34991

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NPSAT1Spacecraft Architecture and

Technology Demonstration Satellite

Space Systems Academic Group777 Dyer Rd., Code (SP/Sd)

Monterey, CA 93943http://www.sp.nps.navy.mil/npsat1

dsakoda@nps.edu(831) 656-3198

20050715

Agenda

• NPS Space Education• NPS Space Flight Experiments Background• NPSAT1 Objectives• Relevance to DoD• Program Schedule

NPS Space Education

• Two Curricula: Engineering and Operations• Broad Scope of Disciplines (interdisciplinary

education)• Master’s Thesis Requirement on Space-

Related Topic• “Capstone” Design Course• Six-Week Experience Tour• Space Cadre / Space Professional

NPS Space Flight Experiments

• “Hardware-in-the-loop education”• Space thermo-acoustic refrigerator (STAR)• Ferroelectric materials in space

– “Piggyback” experiment– APEX & DATASAT-X

• Small Satellite Design Program– Full life-cycle development– PANSAT (Discovery Shuttle, STS-95, 1998)

PANSAT Launch & Deploy (Oct. ‘98)

NPS Facilities (cont’d.)

• PANSAT ground station• EMI shielded enclosure• Solar simulator• CAD/CAE Tools• Tensile-testing• Spherical air bearing• Battery test

• Clean room* (class 100,000)• N2 -purged, component storage• Precision machining (CNC mills)• Other test instruments (RF, digital, analog)

* Soft-walled clean room within the lab capable of achieving Class 10,000

NPS Facilities

Vibration Shaker

Thermal-Vacuum

Chamber

Electronics Development & Test

NPSAT1 Objectives

• Address lessons learned with PANSAT• Develop more capable microsatellite bus• Support education and space research with

military relevance– Space system engineering and operations

officer students– NRL-sponsored experiments– NRO-sponsored experiments– Low-cost small satellite technologies

NPSAT1 Overview

• Class D spacecraft• Accepting higher risk• Minimal cost effort• Mission (STP-1) Parameters

• 560 km ± 10 km alt., circular

• 35.4° inclination• ESPA on Atlas V (medium

EELV)• Earliest launch: Sept. 2006

NPSAT1 Configuration

NPSAT1 Experiments

• Supports current DoD needs and research– Lithium ion batteries– Advanced triple-junction solar cells– Two NRL experiments

• Coherent electromagnetic radio tomography (CERTO) beacon

• Langmuir Probe

Lithium-ion Battery

Lithium-ion Battery

• Sony 18650S cell (found in camcorders)• 7 cells in series x 7 strings = 49 cells/battery• Testing on cells

– Vibration– Charge/discharge (vs. temperature & vs. charge rate)

• Prototype battery build/test in-progress– Vibration– TVAC cycling– Charge/discharge (including long-duration)

Vibe & Charge/discharge tests

• Vibration testing– 6 cells tested– Vibe spec per NASA

handbook*• Charge/discharge tests

– 11 cells tested– Characterize performance– Charge rates– Temperature

General Environmental Verification Specification for STS & ELV Payloads, Subsystems, and Components, Rev A, NASA/GSFC, June 1996

NPSAT1 Experiments

• Four NPS experiments– Configurable, Fault-Tolerant Processor

(CFTP) experiment– COTS micro-electromechanical systems

(MEMS) rate sensor – Solar cell measurement system (SMS)– COTS visible imager (digital camera)

NPSAT1 Experiments

• NRL Experiments– Coherent Electromagnetic Radio Tomography

(CERTO)• Three-frequency beacon• Ground stations measuring phase and amplitude

scintillations• Total electron content (TEC) in ionosphere in plane

of observation• Applications to radar, communications, navigation,

surveillance

Multi-Frequency Measurements of Scintillations

• Applications– Radar– Communications– Navigation– Surveillance Systems

• Clients– Naval Space

Command– USAF Space

Command– USAF Space Weather

Service

TEC Measurements

L-Band Scintillations

VHF Scintillations

NPSAT1 Experiments

• NRL Experiments (cont’d.)– Langmuir Probe

• Augments CERTO data• In-situ measurements at orbit altitude

• NPS Configurable, Fault-Tolerant Processor (CFTP) Experiment– Adaptable processor using FPGA– Non-volatile FERRO RAM for configuration memory– Add-on card within C&DH housing– Various applications (triple-modular-redundant computer,

compression algorithms)

NPSAT1 Experiments

• MEMS rate sensor– Use COTS rate sensor

• ±5°/sec range• Three sensors for 3-

axis rates• ±5 V at <80 mA each

– Gain flight experience w/ MEMS devices

– Use during acquisition (low sensitivity at orbital rates)

– Use on a power-available basis

NPSAT1 Experiments

• COTS Visible Wavelength Imager (VISIM)– PC/104 interface card &

CCD camera– PC/104 cpu board– Array: 652 x 492– Raw image: Bayer format– Optics: ~100 m per pixel

PC/104 Camera

NPSAT1 Experiments

• Solar Cell Measurement System (SMS)– Provide flight demonstration of advanced,

triple-junction solar cells– Perform current-voltage (I-V) curve

measurements• 2 experiment cells per cylinder side• Sun vector measurement

– Perform 2 measurements per orbit

NPSAT1 Experiments

• COTS Visible Wavelength Imager (VISIM) (cont’d.)– Generate data for officer students in space

curricula– Research on-orbit processing of data

(compression algorithms, etc.)– Educational outreach

• Have k-12 schools ‘task’ satellite for images• Distribute images via Internet (World Wide Web)• ‘Spark’ interest in engineering / science

System Block Diagram

Backup 3-AxisMagnetometer

3-AxisMagnetometer

Electrical Power Subsystem

Attitude Control Subsystem

Torque Rod DriverMEMS InterfaceMagnetometer Interface

80C196KD MicrocontrollerEDAC MemoryFERRO RAMReal-Time Clock

Solar Cell MeasurementSystem (SMS)

Cell MultiplexingCell Measurement CircuitSun Sensor Circuit

80C196KD MicrocontrollerEDAC MemoryFERRO RAMReal-Time Clock

RF Low Noise Amp(LNA)

Mixer + FilterLO + Filter

Power Supply(+5V DC, +15V DC)

MODEM

Configurable, Fault-TolerantProcessor Experiment

Flash Disk Storage(256 MB ATA/IDE;A/D & Digital I/O)

+28V

15 July 2005

VISIMController

NETWORKPORT

+28V

+32V

+28V

CERTO

C&DH/RF System

MEMSRate Sensors

Solar Arrays2 strings per cylinder side

12 cylinder sidescommercial ITJ cells

RF High Power Amp(HPA)

Mixer + FilterLO + Filter

Digital Serial

Interface TBD

Power

Digital CMDInterface (2-bits)

Sharp ARM 79520 !-proc16 Mbytes EDAC RAM

3 MB EPROM

+28V

X, Y, ZOutput

Analog Signal

+5V, -5V

X, Y, ZOutput

X TorquerCoil

Y TorquerCoil

Z TorquerCoil

0-25 V (+X, -X)

0-25 V (+Y, -Y)

0-25 V (+Z, -Z)+28V

LangmuirProbe (LP)

VISIMCamera

Head

RFTransferSwitch

Zenith-Pointing Antenna

Nadir-Pointing Antenna

RFTransferSwitch

Zenith-Pointing Antenna

Nadir-Pointing Antenna

Power DistributionBattery SwitchingCurrent SensorsDeployables

80C196KD MicrocontrollerEDAC MemoryFERRO RAMReal-Time ClockWDOG Timer

Li-ion Battery

7 cells x 7 strings8.75A-hr, 226Whr

3.7V/cell, 25.9V Battery

22 to 29.4 V

2 Battery Temperatures

Sun Sensors(3 Pairs)

Goodrich 13-515 SunSensing Module -15V to -5V

0 to 1mA

Legend

CERTOAntenna

LPSensor/Boom

Coaxial Cable

Deployment

4-bit Digital Control

Exp. Solar Arrays1 string per cylinder side

12 cylinder sidesExperimental ITJ cells

Analog Data (4 twisted pair)

Deployment Monitoring

22 TripleJuntion Test

Cells, 2Standard Cells

MomentumWheel

28 ± 4V

RS422

GPS Receiver

NPSAT1 Antenna Design

• Theses completed under J. Lebaric and R. Adler– Mahmut Erel (design/sim)– Ilhan Gokben (test/validation)

VPOL Measured and Calculated Transmitting Antenna Gain for Φ = 180°

NPSAT1 Design Overview: Structure

• Robust, aluminum frame & panels

• Inherited parts from excess property

• Modifications made– New solar panels &

Extension on ‘top’– Component mounting– VISIM FOV (hole)

NPSAT1 Schedule

Earliest launch: Sept. 2006NPSAT1 earliest delivery: June 2006System-level testing complete: May 2006Spacecraft Build: Feb. 2006

NPSAT1 Web Site

For more information . . .http://www.sp.nps.navy.mil/npsat1

Thesis topics:http://www.sp.nps.navy.mil/npsat1/education/educationpage.htm