October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20061
Systems Engineering in Venus Satellite
How to benefit from system engineeringprocess in designing a microsatellite
Jacob HerscovitzVenus Project Manager
RAFAEL - Israel
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20062
Presentation Contents
Presentation goal:• To demonstrate the applicability of SEP and
Conceptual design (preliminary design) in context of spacecraft and space mission engineering.
• Introduction of the Venus program• Description of the synthesis step of the Systems
Engineering Process (SEP)• Example of synthesis in Venus Program:
– Solar panels and Thrusters configuration • Conclusions
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20063
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20064
Venμs ProgramVegetation and Environment New μSatellite
• A Joint Israeli (ISA Via IAI and RAFAEL) French (CNES) Program • Dual missions:
– Scientific Mission: A research demonstrator mission for the GMES program (Global Monitoring for Environment and Security), dedicated to monitoring vegetation and water quality – using a Multi-Spectral camera
– Technological Mission: Validation of the Israeli Hall Effect Thruster (IHET) and demonstration of its mission enhancement capabilities:
• Orbit maintenance, • LEO to LEO orbit transfer• Enabling imaging mission in a high drag environment.
• Venus platform based on IMPS design of IAI• Estimated launch weight: 230 kg• Launch in 2009• Planned lifetime of 4¼ years
Ben Gurion University
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20065
Venus MissionVM1
IOTVM1a
VM1b
IHET
VM1aT
IHET
VM1aS
IMAGING Oct. 15
Nov. 14
VM2
(Orbit Transfer)
Launch
VM3VM3a
VM3b
IHET
VM3aT
IHET
VM3aS
IMAGING Oct. 15
Nov. 14DisposalImagingmission
IHETmission
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 20066
VM1 Mission Characteristics
• Orbit: near polar, sun-synchronous, earth repeating • Altitude: 720 km• Inclination: 98.27°• Revisit time: two days (29 revolutions)• Equator crossing time: 10:30 AM, descending mode• Mission start & duration: June 2009, for ~4.25 years• Imaging:
– Swath: 27.56 km– Spatial resolution: 5.3 m– Number of spectral bands: 12 (VIS-NIR)– Tilting capability: +/-30° across and along track – Radiometric resolution: 10 bits
7
Monitoring of Temporal DynamicsMonitoring of Temporal Dynamics
21 March 23 April 15 May 14 June 20 July
14 August 14 September
6 October 27 October
22 November
After compositing procedures for eliminating clouds, VENµS will provide images with improved spectral information every 10 days
Crop evolution as seen by the SPOT constellation every month 2000 m
8
Coastal Zone ApplicationsCoastal Zone Applications
9
Pollution Dispersion – 11 – 25, June 2001Pollution Dispersion – 11 – 25, June 2001
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200610
VM1 Imaging Access
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200611
IHET- 300W
Isp @ 300W : >1300s Thrust @ 300W: ≥15mN Total Impulse: >50 KNs
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200612
Thruster operating principles
• Xe gas directed through distribution channel (Anode)
• Electrons emitted from cathode, collide with Xe atoms, and ionizing them.
• Induced magnet field, spiral ions movement in the thruster channel.
• Electric field accelerates ions out of the channel.
• Ions neutralization at exit by electrons from the cathode.
PlasmaJet
B
B
Anode\Gas-Distributor
Electron Hall current
Hollow Cathode
Ions
E
B
Electrons
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200613
VM3 Combined Scientificand Technological MissionsImaging orbits in Yellow, IHET orbits in blue
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200614
Venus Launch
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200615
Venμs – System of Systems• Space segment – Venus satellite:
• Venus platform (IAI & Rafael, Israel)• Venus Super Spectral Camera (ELOP, Israel)• Israeli Hall Effect Thruster- IHET (Rafael, Israel)
• Launch segment – DNEPR (Kosmotras, Russia & Ukraine)
• Ground segment:• Command and control center (MBT, Israel)• X-band receiving station (Kiruna, Sweden)• Image processing center (CNES Toulouse, France)• Technological Mission Center (Rafael, Israel)
• Orbits and Missions• Scientific mission: Multispectral imaging for
agriculture, vegetation and water quality• Technological mission: Validation of IHET and
mission enhancement demonstration• Orbits: Initial orbit (720km), LEO to LEO transfer and
Final orbit (410km)
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200616
Tier n
Tier 2: Sub-System
Tier 1: System
SEP (Systems Engineering Process) Performed in System Tiers
SEP
Tier 0: System of Systems
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200617
Example of synthesis in Venus Program:
Solar Panels and IHET Architecture for Venus Satellite
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200618
Define the Design Problems:
Define Solar Panels and IHET geometric placement architecture on the Venus satellite (orientation of panels to IHET and satellite platform).
Main Functional Requirements:• Provide power:
– 350W for IHET – 150W for platform,
for maximum duration (Required: > 20 mins, Desired: ~60 mins)• Provide maneuverability in orbit• Provide propulsion redundancy• Provide camera protection from ATOX
Constraints:• Venus orbits: Sun-Synchronous, descending node @ 10:30• Restricted maneuvers of “ROLL” about thrust vector.
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200619
Possible Solutions to Solar Panels Problem
IAI-MBT “Ofeq” Lockheed Martin “Ikonos”
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200620
Possible Solutions to IHET Problem
ESA “Smart1” NASA & JPL “Deep Space 1”
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200621
Panels & IHET configuration
IHET Location
Solar Panels
A1 A2 B1 B2 B3
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200622
The 5 Concepts
A1 A2
B1 B2 B3
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200623
Basic Solar Panel and IHET Architecture Alternatives
Thrust
Panel
“Normal”
Thrust
Panel
“Parallel”
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200624
Alternatives “Normal”
Thrust
Sun
“Normal”
A2
B1
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200625
Alternatives “Parallel”
Thrust
Panel
“Parallel”
A1
B2 B3
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200626
Power Generation Analysis for Solar Panels – IHET Architecture “Normal”
Thrust
Panel
0 1000 2000 3000 4000 5000 6000
2
4
6
8
10
12
14
16
18
20E.P. (Sun Tracking Mode) - Minimum Power Minutes [watts]
Orbit Number
Min
utes
450500550
VM1 (720km)
0 1000 2000 3000 4000 5000 60000
2
4
6
8
10
12
14
16
18
20E.P. (Sun Tracking Mode) - Minimum Power Minutes [watts]
Orbit Number
Min
utes
450500
VM3 (410km)Number of orbit minuteswith minimum power
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200627
Power Generation Analysis for Solar Panels – IHET Architecture “Parallel”
Thrust
Panel
0 1000 2000 3000 4000 5000 60000
5
10
15
20
25
30
35E.P. (Sun Tracking Mode) - Minimum Power Minutes [watts]
Orbit Number
Min
utes
450500550
VM1 (720km) VM3 (410km)Number of orbit minuteswith minimum power
0 200 400 600 800 1000 1200 1400 1600 18000
5
10
15
20
25E.P. (Sun Tracking Mode) - Minimum Power Minutes [watts]
Orbit Number
Min
utes
450500
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200628
Drag Consideration
Imaging Operation
IHET Operation
1.463.51.463.5
1.463.51.463.5
1.463.50.42
1
Concept
13.5Area [m2]
0.420.42Drag [mN]11Area [m2]
0.421.46Drag [mN]
• Computations for VM3 @ Altitude: 410 km• Satellite mass: 150 kg • Panels area: 2.5 m2
• Satellite body area: 1 m2
• Assume Solar-Max conditions (*) (year 2010)
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200629
Drag Results Analysis
• Drag impulse of one orbit (Altitude = 410km, Orbit period = 92 min): – For concepts A1, B2, B3 (A = 3.5m2): 8.1 Ns– For concepts A2, B1, (A = 1m2): 2.3 Ns
• Typical IHET impulse (13mN for 20 min.) operation: 15.6 Ns
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200630
Evaluation Criteria
• IHET operation minutes / orbit (for 500W consumption in 720km and 410km orbits)
• Need for Camera Cover• ΔV flexibility – Capability of ± ΔV for orbit maneuvering• Heritage – usage of legacy components• Integration complexity – IHET and satellite integration
effort due to modularity and coupling
• VM1 (2 years) specific:– N/A
• VM3 (3rd year) specific:– Drag during Imaging and IHET operation– Enough IHET power during orbits for orbit maintenance
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200631
Concepts Evaluation
A1 A2 B1 B2 B3Imaging 0.42 0.42 1.46 1.46 1.46IHET 1.46 0.42 0.42 1.46 1.46
15 - 22 11 11 15 - 22 15 - 22Must Optional Must Optional Optional
-ΔV @ dawn+ΔV @ dusk ±ΔV @ noon ±ΔV @ noon
-ΔV @ dawn+ΔV @ dusk
±ΔV @ dawn±ΔV @ dusk
New New Tecsar (3) Tecsar (3) Tecsar (3)
Low Moderate Low Moderate Mederate
Concept
Criteria
ΔV flexibility
Drag (1) [mN]
500W minutes / orbit (2)
Camera Cover
HeritageIntegration Complexity (4)
Existing ExistingExisting
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200632
Criteria Weight A1 A2 B1 B2 B3Drag Considerations 10 1 0 -2 -2Power Production Capability 25 -2 -2 0 0Camera Risk (Need for camera cover) 20 3 0 3 3ΔV flexibility (maneuverability) 25 -2 -2 0 3Heritage Design (Solar Panels) 15 0 2 2 2IHET Integration Complexity 5 -2 0 -2 -2Total 100 0 -40 -70 60 135
DATUM
Concept Selection
Pairs Comparison GradeMuch better than datum 3Better than datum 2Slightly better than datum 1Same as datum 0Slightly worse than datum -1Worse than datum -2Much worse than datum -3
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200633
Design Improvements
Minimum Minutes of power at VM3 (IHET maneuver)
010203040506070
0 10 20 30 40 50 60 70 80 90
Thruster-Panel angle [deg]
Min
utes
Minutes @ 550W Minutes @ 600W
Minimum Minutes of power at VM1 (IHET maneuver)
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60 70 80 90
Thruster-Panel angle [deg]
Min
utes
Minutes @ 550W Minutes @ 600W
ATOX
0
2
4
6
8
10
0 10 20 30 40
Tilt Angle [deg]
10e2
0 A
TOX/
cm2/
year
Camera Tolerance:7.3 1020 ATOX/m2/Y
Optimal power
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200634
Final IHET Configuration
25º
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200635
Conclusions
• System of systems design process can benefit from applying the SEP starting from the initial conceptual design phase
• SEP and synthesis tools are easily applicable to the first tiers of system engineering, as they are to the detailed design tiers
• The applicability of SEP and Conceptual design (preliminary design) was demonstrated in the context of spacecraft and space mission engineering
• Using quantitative synthesis methods can produce a reasonable and rational design
October 24th, 2006J. Herscovitz - 9th Annual Systems Engineering Conference, NDIA 200636
Thank You
Contributed to work presented in this presentation:• Dr. Hezi Atir - Chief Scientist, Space Systems Directorate, Rafael• Danna Linn-Barnett – Mission Analyst, Space Systems Directorate, Rafael• David Reiner – Propulsion Section Head, Rafael• Yoram Yaniv & Meidad Porat Pariente – Program Management & System
Engineering, MBT-IAI• Prof. Arnon Karnieli - The Remote Sensing Laboratory, Ben-Gurion University of the
Negev
Jacob HerscovitzSpace systems [email protected]
Top Related