NPSAT1 Spacecraft Architecture and Technology Demonstration Satellite Brief to SS3011 Space Technolo

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NPSAT1Spacecraft Architecture and Technology
Demonstration SatelliteBrief to SS3011 Space
Technologyand Applications

• Presented by
• Dan Sakoda
• Space Systems Academic Group
• 777 Dyer Rd., Bldg. 233
• Code (SP/Sd), Rm. 125
• Monterey, CA 93943
• [phone]

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Introduction

• Space Systems Education at NPS
• Small Satellite Design Studies Background
• NPS Facilities
• NPSAT1
• Mission Overview
• Bus Architecture
• Experiment Platform

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NPS Space Program

• Space Systems Operations
• Space Systems Engineering
• Space-Related Research
• Spacecraft Technology
• Space Environmental Effects on Semiconductors
• Spacecraft Design

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NPS Space Curricula

• Two Curricula Engineering and Operations
• Broad Scope of Disciplines (interdisciplinary
  education)
• Masters Thesis Requirement on Space-Related
  Topic
• Capstone Design Course
• Six-Week Experience Tour

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Space Systems Operations

• Space Systems Operations
• Master of Science in Systems Technology
• Eight-quarter program
• Broad Technical Overview
• Space sciences / engineering
• Information technology
• Operations analysis
• Acquisition management

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Space Systems Engineering

• Master of Science in one of five science or
  engineering disciplines
• Nine-quarter program
• Matrix of core technical courses
• Specialization sequence for concentration in
  selected discipline

Astronautical Engineering Computer
Science Electrical Engineering Mechanical
Engineering Physics
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NPS Smallsat Program Background

• Hardware-in-the-loop education
• Space-flight experiments
• Space thermo-acoustic refrigerator (STAR)
• Ferroelectric materials in space
• Piggyback experiment
• APEX DATASAT-X

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NPS Smallsat Program Background

• Complete spacecraft development
• Full life-cycle development
• Design, development, integration test
• Launch and on-orbit operation
• PANSAT (Discovery Shuttle, STS-95, 1998)
• Microsatellite (digital communications)
• Still operating (beyond 2-year design life)

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PANSAT Launch Deploy (Oct. 98)
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NPS Facilities
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NPS Facilities (contd.)

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

• Clean room (class 10,000)
• N2 -purged, component storage
• Precision machining (CNC mills)
• Other test instruments (RF, digital, analog)

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NPSAT1 Mission Overview

• Objectives
• Educational tool
• Demonstrate low-cost, COTS architecture
• PC-compatible command data handling (CDH)
  subsystem
• POSIX-compliant operating system (Linux)
• Demonstrate COTS technology for smallsats
• FERRO RAM
• Li-ion polymer batteries

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NPSAT1 Mission Overview

• Mission Requirements
• 2-year mission life (min.)
• 550 km-800 km, circular
• 30-80 inclination
• Secondary payload on a number of launch carriers
• 3-Axis ACS (10 each axis)
• NPS command ground station

• MLV-05 Parameters
• 560 km 10 km altitude, circular
• 35.3 inclination
• ESPA on Delta IV (medium EELV)
• Lightband separation system

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NPSAT1 Mission Overview

• Objectives (contd.)
• Experiment platform
• Two NRL experiments
• Coherent electromagnetic radio tomography (CERTO)
  beacon
• Langmuir Probe
• Three NPS experiments
• Configurable processor experiment (CPE)
• COTS micro-electromechanical systems (MEMS) rate
  sensor
• COTS visible imager (digital camera)

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NPSAT1 Experiments

• NRL Experiments
• Coherent Electromagnetic Radio Tomography (CERTO)
• Two-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

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NPSAT1 Experiments

• NRL Experiments (contd.)
• Langmuir Probe
• Augments CERTO data
• In-situ measurements at orbit altitude
• NPS Configurable Processor Experiment
• Adaptable processor using FPGA
• Non-volatile FERRO RAM for configuration memory
• Add-on card within CDH housing
• Various applications (triple-modular-redundant
  computer, compression algorithms)

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NPSAT1 Experiments

• MEMS rate sensor
• Use COTS rate sensor
• 5/sec range
• Three sensors for 3-axis rates
• 5 V at
• Gain flight experience w/ MEMS devices
• Use during acquisition (low sensitivity at
  orbital rates)
• Use on a power-available basis

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NPSAT1 Experiments

• COTS Visual Imager (VISIM)
• PC/104 interface card CCD camera
• PC/104 cpu board
• Array 652 x 492
• Raw image Bayer format
• Custom optics for

PC/104 Camera
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NPSAT1 Experiments

• COTS Visual Imager (VISIM) (contd.)
• 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

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NPSAT1 Design Objectives

• Low-cost design (
• Utilizing existing hardware (structure solar
  cells)
• Power mgmt. duty cycle electronics
• Subsystems
• Experiment payloads
• Single-string design

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NPSAT1 Configuration

• Overall dimensions 75.4 cm (29.7 in.) height x
  50 cm (20 in.) diam.
• CERTO deployable antenna
• Deployable Langmuir probe
• Deployable tip mass on GG boom
• 1.07-inch (height) launch vehicle interface
  (Lightband)

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NPSAT1 Configuration
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System Block Diagram
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NPSAT1 Design Overview CDH

• CDH
• X86 processor (Intel386EX)
• Error-detection-and-correction (EDAC) RAM
• PC/104 bus interface
• IDE disk storage
• Serial test interface via PPP

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NPSAT1 Design Overview Software
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NPSAT1 Design Overview ACS

• ACS
• 10 pointing accuracy
• 0.66/sec max. rates
• Similar control electronics as EPS
• Actuators magnetorquers
• Sensors 3-axis magnetometer and solar panel
  currents
• On-board orbit propagator

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ACS Block Diagram
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NPSAT1 Design Overview EPS

• Rad-hard parts micro-controllers RAM in both
  EPS ACS
• Electrical Power Subsystem (EPS)
• 28V bus
• Silicon solar cells / Li-ion polymer batteries
• DC/DC conversion at the subsystem
• Watchdog timer for resetting CDH

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NPSAT1 Design Overview Communications

• Communications Subsystem
• GMSK modulation
• Full Duplex
• 100 kbps data rate
• Uplink at 1.767 GHz
• Downlink at 2.207 GHz

Modem Development System
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NPSAT1 Design Overview Structure

• Mechanical Structure
• Robust, aluminum frame panels
• Inherited parts from excess property
• Necessary modifications
• Launch vehicle interface
• New solar panels
• Extension on top
• Component mounting
• VISIM FOV

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NPSAT1 Design Overview Structure
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NPSAT1 Design Overview Thermal

• Thermal
• Li-ion polymer batteries 0 to 45 C
• Electronics -25 to 85C (industrial grade)
• Preliminary analysis cold environment
• Average spacecraft power 31.5 W
• Batteries requiring thermal isolation heaters

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SDRC I-DEAS Thermal Model

• Orbital Parameters
• 550 km, circular orbit
• Beta angle (angle between orbit plane and sun) of
  zero
• Heat Input
• Constant heat input of 31.5 W
• Distributed over three lower equipment plates (8
  W on upper-mid, 10 W on lower-mid, 13.5 W on base
  plate)
• Transient Analysis
• Duration 1/2 day
• Results Output 120 sec

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I-DEAS Thermal Results
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(/- X)-Facing Panels
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(X)-Facing Panel Temperatures
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(X) Panels Single Orbit
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Solar Panel Thermal Analysis Results

• Overall range of temperatures 30C to -22C
• /- X Panels showing extreme temperatures
• Max. Temperature
• Min. Temperature -22C
• Leading edge (X) panels slightly warmer than
  (-X) trailing edge panels
• No appreciable difference between positive Y
  panels and negative Y panels
• Max. Temperature
• Min. Temperature -19C

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NPSAT1 Design Overview

• Experiments
• Must be able to duty-cycle (power off)
• Can use telemetry command (TC)
• On-board memory storage available
• Can use real-time clock

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NPSAT1 Web Site
For more information . . . http//www.sp.nps.navy.
mil/npsat1