System Outline of Small Standard Bus and ASNARO Spacecraft
System outline of small standard bus and ASNARO spacecraft
August 11th, 2009 NEC Corporation, USEF, NEDO Toshiaki Ogawa, Kenichi Saito, Keita Miyazaki, and Osamu Ito Outline
1. Introduction 2. ASNARO spacecraft system outline 3. Standard bus system 4. Optical Mission 5. Conclusions
1 1. Introduction
2 NEC Space heritage(1/3) NEC 1st and recent satellites
OHSUMI DAICHI (ALOS) Japan’s 1st sat. Earth Observation Launched： Launched：2006 1970 Mass：4000kg Mass：24kg
KAGUYA KIZUNA (WINDS) (SELENE) Communication Luna Observation Launched：2008 Launched：2007 Mass：2700kg Mass：2900kg (On-Orbit)
Courtesy JAXA
3 NEC Space heritage(2/3) NEC Small Satellites
HAYABUSA TSUBASA (MDS-1) (MUSES-C) Engineering Test Observation of Launched：2002 Asteroid ITOKAWA Mass：480kg Launched：2003 Mass：510kg
KIRARI (OICETS) Planet-C Optical Venus Observation Communication Launched：2010 Launched：2005 (Planned) Mass：570kg Mass：500kg
(C)Akihiro.Ikeshita Courtesy JAXA
4 NEC Space heritage(3/3) NEC Optical Sensors
PRISM (ALOS) Resolution:2.5m Launched:2006 MESSR (MOS-1) Resolution:50m Launched:1987
ASTER/VNIR (Terra) NASA/courtesy of nasaimages.org Hyper Spectral Sensor Resolution:15m Resolution:30m Launched:1999 Under developing
5 Background
ASNARO ： Advanced Satellite with New system ARchitecture for Observation What’s this ? Light • Small Satellite for Optical Earth Weight Observation with high resolution optical sensor from LEO by precise 3-axes pointing control. High Low Cost Performance Characteristics of ASNARO • High Performance – High Resolution Fast – High Agility Delivery – High Data Rate Transmission • Adopt Standard Bus concept – Lower Cost – Lighter Weight – Faster Delivery *developed by NEC Co. and Institute for Unmanned Space Experiment Free Flyer (USEF) under the contract with New Energy and Industrial Technology Development Organization (NEDO).
6 2. ASNARO spacecraft system outline
7 ASNARO spacecraft system outline
GPS Antenna S-band Antenna X-band Antenna Baffle Imager Payload Camera
Star Tracker Bus Payload Equipment
Thruster
Solar Array Panel
On-orbit Configuration
8 Observation Mode
Observation Mode a. Snap Shot mode acquire the nominal 10 x 10 km area’s image. This mode is basic observation mode.
b. Wide View mode acquire wide area’s images which are consisted of a few sets of neighboring snap shot images.
(a) Snap Shot mode (b) Wide View mode c. 3D mode acquire the stereo image of the observing area. In this mode, the observations are performed two different orbital positions to obtain 3 dimensional information of the concerned area.
d. Strip Map mode acquire zonal image which is up to 850 km of continuous image by 10 km width. The maximum observable time is continuous 120 seconds. (c) 3D mode (d) Strip Map mode
9 3. Standard bus system
10 Standard bus Concept
• Standardized payload interface – Mechanical interface – Thermal interface – Electrical interface – RF interface • Minimized interface lines between payload and bus – SpaceWire 1m – Timing Signals – Power lines – Temperature control lines. • Compatible with various rockets – JAXA new solid rocket 1m 1m – H-IIA – DNEPR – … External figure of Standard bus system • Various options for user requirements – Solar array power – Solar array type (fixed or rotate) – Number of STT (1 or 2) – Number of Payload Heater/EED lines – Single bus or partial redundant bus
11 Applications
Under Developing Under Developing
Optical Sensor Scientific Telescope (JAXA/ISAS)
Planned
SAR Sensor Hyper Spectral Sensor Infrared Sensor
12 SpaceWire SpaceWire network technology
What’s this ? • One of the protocol for network in spacecraft, established by ECSS (promoted by JAXA/ISAS in Japan).
Advantage of SpaceWire • Standardized physical interface and network protocol. • Communicate in high speed. • Plug and Play • The system configuration and the performance ASNARO system network diagram are flexible. • The number of the harness can be decreased.
13 Small On-board Computer
Versatile Computer
¾ Desk top PC size & light weight ¾ New 64bit space MPU (HR5000) developed by JAXA ¾ Applying Network technology → Flexible configuration corresponding to mission requirement
Conventional design New architecture
16bit HR5000 Memory & 175mm Memory MPU (64bit) Auxiliary circuit
Auxiliary circuit router
Function A B C 220mm Function Function Function A B C 70mm
14 SpaceWire Router
SpaceWire Router
¾ A6 size footprint & light weight ¾ 14 ports or 28 ports (14 ports x 2 in one unit) ¾ Applying Network technology → Plug & play architecture can be applied
Conventional design New architecture
14 ports Router Network Bus Host Computer (Development model) controller
UNIT SpW A router 1553B UNIT B UNIT UNIT UNIT A B C UNIT C
15 SpaceWire -Flexibility of mission-
Optical sensor mission DH Computer
Router
Mission Payload I/F Optical Computer Unit Sensor
Mission change
SAR sensor mission DH Computer
Router
Mission Payload I/F SAR Sensor Computer Unit
SpaceWire exclusive line
16 SpaceWire - High-reliability of bus system -
DH Computer Single Bus Configuration
Router
TMTC EPS RF Processor
High-reliability
redundancy
DH Computer DH Computer
redundancy Router TMTC RF Processor
TMTC EPS RF Processor
SpaceWire TMTC：Telemetry and command exclusive line
17 4. Optical mission
18 Optical Payload Specifications
Item Specification Observation Method Push-Bloom Scan Observation Bands Panchromatic Band Multi-spectral：6 Bands Grand Sample Distance Panchromatic: < 0.5m (GSD) Multi-spectral: < 2.0m Swath Width > 10km
19 OPS View
20 Silicon Carbide Mirror
New Technology SiC （NTSIC) Material ~ Developed by NTSpace / Toshiba
General Features of SiC ¾ Comparing with glass material, 9 Excellent specific stiffness (stiffness / density) 4 times larger than glass 9 Low thermal distortion 9Excellent thermal conductivity Advantages of NTSIC ¾2 times higher strength than usual SiC ¾ Suitable for visible optics 9NT-SiC surface has no pores. 9 Usable without surface coating
ASNARO Flight Mirror
21 5. Conclusions
22 Conclusions
• ASNARO system is expected to be a pioneer of next-generation.
– By using our new small standard bus, ASNARO is developed at lighter weight, lower cost and fast delivery.
– By adopting SpaceWire technology, it is possible to reduce not only the design works, but also the satellite integration and test activities.
• ASNARO is expected to be launched in 2011 JFY. Now, manufacturing of ASNARO flight model has been already started.
23 Toshiaki Ogawa [email protected] Thank you for your attention !!
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