Pratham
IITB Student Satellite Project
Saptarshi Bandyopadhyay
Project Manager and System Engineer
Pratham, IIT Bombay
15th May, 2011
Student satellite – The Idea!
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Aim - To develop a satellite in
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a time frame of 2-3 years
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be of low cost
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low mass (< 10kgs)
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launch it into orbit
COTS instruments to reduce costs
Success of mission attached to
process of learning, not just final
output
Satellites are test-beds for new
technology that need space
qualification
1.
2.
3.
4.
5.
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8.
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12.
MINI – SPUTNIK
ASUSAT
NCUBE
SSETI
AAU Cubesat
SNOE
ICARUS
CATSAT
DTUSAT
MEROPE
COMPASS
SEEDS
Mission Statement for Pratham

Create a learning experience of working on a real life multi-disciplinary
complex
system.
Learning
enhancement
through
CDIO (Conceive, Design, Integrate and Operate). http://www.cdio.org/
Acquiring knowledge in Satellite
and Space Technology.
Have the Satellite entirely designed
by the student body of IIT Bombay.
Have the Satellite launched;
measure TEC of the Ionosphere
above IITB.
Involve students from other
universities in our Satellite project.
Description
Mission
Success
Flight Model ready
85%
Beacon Signal received
90%
TEC measurements at
IITB
Satellite functional for 4
months
95%
100%
Information about Pratham
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Weight: ~10 kgs
Size: 260mm X 260mm X
260mm
Payload: Measuring TEC
Orbit: 10:30 polar
sun-synchronous, 817km
altitude
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Downlink at 2 frequencies
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Uplink used as kill switch
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4 months mission life
Student Team Size: 7
(usually 25)
Departments:
Aerospace
Chemical
Civil
Computer Science
Electrical
Physics
Mechanical
PRATHAM
Core Group
(10 members)
Quality Team
Comm.
Power
Structure
Payload
Integration Team
OBC
Control
Thermal
Social Goal
Technical Mentors
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Prof K. Sudhakar (Aero)
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Prof R. K. Pant (Aero)
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Prof P. M. Mujumdar (Aero)
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Prof K. K. Isaac (IIST)
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Prof H. Arya (Aero)
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Prof U. N. Gaitonde (Mech)
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Prof H. B. Hablani (Aero)
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Prof R. K. Shevgaonkar (PU)
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Prof S. P. Bhat (Aero)
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Prof R. N. Banavar (Syscon)
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Prof K. Chatterjee (Elec)
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Prof B. G. Fernandes (Elec)
Prof D. K. Sharma (Elec)
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Prof R. P. Shimpi (Aero)
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Prof Girish Kumar (Elec)
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Prof Kavi Arya (CS)
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Prof B Bandyopadhyay (Syscon)
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Prof C. Amarnath (Mech)
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Prof K. N. Iyer (Mech)
Dr K P Ray (SAMEER)
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Prof Madhu N. Belur (Elec)
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Prof Krithi Ramamritham (CS)
Documentation and Reviews
Work done
by Pratham
Team
Once every week
Reviewed by the Team
Once every month
Reviewed by the IITB Faculty
Once every 2-3 months
Reviewed by the ISAC Engineers
End of Design Phase
Once every 6-10 months
Rigorous reviews by the IITB
Faculty Mentors & ISAC
Engineers
IITB Faculty Mentors: 30
Departments:
Aerospace
Computer Science
Electrical
Mechanical
Systems and Controls
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Major emphasis on documentation since “We want to preserve our knowledge”
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All our documents are available on our website www.aero.iitb.ac.in/pratham/
Timeline
Team Size = 30
Two stage selection process
Quiz & Presentation
Launch
End of 2011
Detailed
Design Phase
Aug 2010
25
Apr 11
Mar 10
Signed MoU
with ISRO
Sept 2009
Sept 09
20
Preliminary Design
Phase finished
Dec 2009
Sept 08
Oct 07
Requirements Capture
Phase finished
Apr 2008
Conceptual
Concept
Design Phase
feasibility
finished
proved to IITB
Aug 2008
Aug 2007
20
Continuity Plan
Documentation
Payload Sub-System
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Measure Total Electron Count of
the Ionosphere over India and
France
Expected TEC value is 25±5
TECU (resolution of 0.1 TECU,
SNR of 500)
2 polarized radio signals are
transmitted parallely
Faraday rotation changes their
angle of polarization
The difference in their
polarization angles is measured
at the ground station
IONOSPHERE
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F2 Region
F1 Region
E Region
D Region
Communication
Sub-System
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Low bit rate Beacon (145.980
MHz)
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High bit rate (1.2kbps)
Monopole for downlink of data
(437.455 MHz)
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CW transmitter, 0.6 Watt power
Resonant Helical/Non-resonant
Monopole of 18 cm
FSK transmitter, 0.6 Watt power
Resonant Monopole of 17 cm
NO telecommand
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Kill Switch (Uplink) added to
satisfy IARU’s constraint for
getting license
Resonant Monopole of 17 cm
Beacon
Rotor
Crossed Yagi
Base Station
OBC, ADCS and Power
SENSORS
SunSensor
(LEOS)
Solar Panels
On 4 sides
(ISAC)
OBC Circuit
Magnetometer
(Honeywell)
GPS
(ACCORD)
Power Circuit
ACTUATOR
Magnetorquer
Battery (ISAC)
ATTITUDE CONTROL
Systems Engineering
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System and Sub-System
Requirements
Mission Design
Weight Budget
Configuration Layout
Connectivity Diagram
Integration Sequence
Mechanical Subsystems
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Structural simulation of the
satellite under launch loads
Thermal design of the satellite
Integration with IBL230V2 LVI
Testing and Quality Assurance
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Electrical Quality ~0.98
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Mechanical QA ~1
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Validated by testing
Level 1 testing done by
individual Subsystems
On Board Computer In Loop
Simulations (OILS)
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From quality calculations, at the
end of mission life
Level 2 testing of Power, OBC,
Controls, and Communication
Clean Room built (100,000 class)
Interaction with students from
other universities
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National Ground station
workshops
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11 participating universities
building Ground Station for
Pratham
MHRD Virtual
Experiments
2 papers published at the
International
Astronautical Congress
2010 in Prague
Collaboration with IPGP
and Paris Diderot
Organizations Supporting Pratham
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ISRO
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ISAC
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VSSC
IIT Bombay
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IRCC
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CDEEP
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AEA
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SAMEER
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TIFR
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Boeing