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By Matthew Patterson Low Earth Orbit Nanosatellite Integrated Distributed Alert System Why focus on Nanosats? –The cost and time to design, develop and complete an entire mission for typical large satellites is enormous. –Microsatellites and Nanosatellites allow quicker mission overturn. –Risk for missions are reduced –Provide a means to test new scientific technologies –Because we have the ability to complete an entire mission from concept design to launch The LEONIDAS Team •Project Director-Dr. Luke Flynn •Principal Investigator- Lloyd French Aukai Kent – Payloads Jennie Castillo – Orbits Dennis Dugay - Communications Kaipo Kent – Thermal Matt Patterson - Power Lynette Shiroma - Attitude & Control Zachary Lee-Ho - Systems Engineer Minh Evans – Command & Data Handling Mike Menendez - Structure and Mechanical Devices What have we accomplished? •Learned the basic concepts in mission design and development •Developed a mission concept report for the LEONIDAS BUS •Prepared proposal for Air Force Office of Scientific Research University Nanosatellite Competition •Presented our mission design to Jet Propulsion Laboratory and Ames Mission Objectives – We will send a microsatellite into a LEO, sun-synchronous, polar orbit – The microsatellite will serve as a platform for demonstrating scientific technologies – Data attained through the operations of the scientific technology payloads will be transmitted to the ground station – The development, manufacturing and launching of the satellite will serve as an educational tool for aiding the development of students at the University of Hawaii at Manoa Plug and Play Bus Mission Requirements • Satellite must accurately point and orient itself to take a picture of Hawaii • Satellite shall be robust and reliable – This will be accomplished through: • Minimizing the use of mechanical devices • The use of COTS components and interfaces • Operation of payloads or communication with ground station will be accomplished within the 14 minute viewing window of each orbit. • Cost of components must not exceed ~ $500k – Cost estimation does not reflect the cost for structure and sublimation thrusters • All scientific demonstrations will be performed within the projected mission lifetime of six months • The shall be sufficient amount of battery power to operate the satellite for a duration of 12 hours, in the event the photovoltaics should fail. Power Regulation and Distribution Power Management and Distribution • Objective: – To provide, store, distribute, and control the satellites power at Beginning of Life (BOL) and End of Life (EOL). • Key Requirements: – To provide a continuous source of power to loads and subsystems through out the mission life (6 months – 1 year). – Support and distribute different voltages (3, 5, +-12, 28V) to variety of loads. – Provide enough power to support peak electrical load and provide enough power at total loss of solar cells for 12 hrs. – Protect against failures in the System. – Fit volume and weight budget: 20x27x11[cm3], 4.1 kg Space Shunts PV Batteries TT&C Sun Thermal PV PRU PDU ACS Earth Payloads C&DH Batteries PV Shunts Space PV: Ultra Triple Junction Cells GaInP/GaAs/Ge (Gallium Indium diphosphate/Gallium Arsenide/Germanium) • Bare Cells – Weight = 76.608 mg – Dimensions = .5 x .22 (m) – Thickness = ~ 0.140 mm • Operating Temperature range = (0˚C – 75 ˚C) – For every degree off, degrades by .5% • UTJ – – – • BOL – Power @28.3%x1,367 W/m2(average solar illumination intensity) = 386.86 W/m2 – Power of Sat : 386 W/m2 x .114 m2 = 44 W per panel – Peak Power output of solar panels (ideal 3 panels) = 106.225 W EOL (5 year lifetime) – Power @24.3% = 332.181 W/m2 – Power of Sat = 37.9 W per panel – Peak Power output of solar panels = 91.499 W • (Ultra Triple Junction) Solar Cell BOL average efficiency = 28.3% EOL average efficiency = 24.3% Degrades .8% per year Rechargeable Lithium-ion Battery • Characteristics – Height = .065 m – Width = .060 m – Thickness = .0196 m – Weight = .153 kg – Energy = 26 Wh – Life = 500 cycles – Charge Temp range = (-20˚C – 75 ˚C) – Charge rate = 2 to 3 hrs @ 6.8 A • # of batteries = ? – In order to meet last for 12 hrs at total failure of Solar Cells # of batteries needed to operate = 16 Power Regulation Unit HESC 104 High Efficiency and Smart Charging Vehicle Power Supply • Characteristics – Length = .09525 m – Width = .09017 m – Height = .01524 m – Weight = .186 kg – Temp range = (-40˚C – 85 ˚C) – Charge Current = 0 to 4 A – Charge Voltage = 9.5 to 19.5 V – Input Voltage = 6 to 40 V • Provides for 3, 5, +-12 V Analysis of Requirements • • Given: – WBol, avg = 106.225 W – WEol, avg = 91.499 W Need: – Wpeak, bus = 76 W x 30% = 99 W – Wellipse, bus = 40 W x 30% = 52 W • Weight < 4.1 kg .186 kg (PRU) 76.608 mg (Bare Cells) +.153 kg x 10 (batteries) 1.716 kg +casing for solar cells, extra batteries, more PRU’s if needed, wires, resistors) < 4.1 kg • Volume: < 20x27x11 cm – PRU = 9.5 x 9.0 x 1.5 cm – Battery = 6.5 x 6.0 x 1.96 cm Plenty of room because the batteries may be in their own side compartment. • Temperature, to satisfy all = (0˚C – 75 ˚C) • Life – Ideally we can last for 2 yrs. If everything doesn’t degrade faster than expected and still needing the same power. What’s left? • Everything!!!! • Cost • Integrating – My parts – Sats parts • Case for solar panels meeting mass budget • Team analysis on subsystems needs • More calculations!!! Gantt Chart Sept AFOSR Oct Nov Dec Jan Feb Mar Done JPL PDR Team Chart Done JPL CDR POWER Sept Find Item Oct Nov Dec Jan Waiting on companies Done My Chart Cost Integrating Research Feb Mar Thank You!! Till the next time!!! Happy Thanksgiving Everyone!!!