UNISAT SATELLITES F. Graziani, F. Santoni, F. Piergentili, FUNDAMENTAL PHYSICS IN SPACE WITH SMALL PAYLOADS (FPS-06) Laboratori Nazionali di Frascati dell’INFN March 21-23, 2006 UNISAT SATELLITES F. Graziani, F. Santoni, F. Piergentili, M. Agostinelli, M. L. Battagliere, F. Bulgarelli, M. Ronzitti, M. Sgubini SCUOLA DI INGEGNERIA AEROSPAZIALE UNIVERSITA’ DI ROMA “LA SAPIENZA” Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza” Contents The UNISAT program aims Spacecraft design, manufacturing, testing, launch, operations Results of UNISAT-3 at 21 months from launch UNISAT- 4 scheduled for launch in June 2006 Examples of technological and scientific payloads Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

Small Satellites for Space Education Practical Training of Whole Cycle of Space Development – Mission conceptualization, satellite design, fabrication, ground test, modification launch and operation – Know what is important and what is not. Importance for Engineering Education – Synthesis (Not Analysis) of an effective system – Feedbacks from the real world to evaluate design, test, etc. Education of Project Management – Four Managements: time, human resources, cost and risk – Team work, conflict resolution – Effective discussion, documentation – International cooperation, negotiation, mutual understanding Department of Aeronautics and Astronautics University of Tokyo Shinichi Nakasuka

Small Satellites for Space Research Reduction of space mission cost using Commercial Off The Shelf (COTS) components Reduction of time from space mission concept to launch (typical time required: 2 years) Technology: test in orbit of state of the art technology Science: small scientific payloads

UNISAT program microsatellites Unisat September 26, 2000 Unisat-2 December 20, 2002 Unisat-3 June 29, 2004 Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza” UNISAT-3 - Sheet Mission  Microsatellite Weight 10 kg Circular Orbit (Sunsynchronous , 750 km height) Structure  Geometry: octagonal prism (150mm side; 250mm height) Materials: Al + Al-Al sandwich Attitude  Passive magnetic Power  - Si and triple-junction solar cells - NiCd Batteries TLC  VHF (145 MHz) uplink; UHF (436 MHz) downlink; 9600 bps; Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

Passive magnetic attitude stabilization A permanent magnet installed on the satellite follows the Earth magnetic field lines Accuracy on the order of 10° Low cost No software development

UNISAT-3 block diagram Antenna MODEM+HDLC Protocol RS-232 Communication Antenna MODEM+HDLC Protocol RS-232 9600 bps Transmitter UHF Telemetry CPU Tone Decoder Receiver VHF Payloads

UNISAT-3 electronic boards

UNISAT - 3 Terrestrial Si Solar Arrays Terrestrial Si solar cell Lateral solar panels Upper solar panel

Low Grade 3J (21%) and Space Qualified Si (15%) Solar Arrays Si Solar Array manufactured by Kiev Polytechnic Institute Triple junction Solar Array

Vibration Test (OCI, Roma)

Vibration test (Dnepropetrovsk)

Separation test (Dnepropetrovsk)

Integration on the DNEPR launcher (Baikonour) UNISAT-3 launch team

Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza” UNISAT-3 Launch Launched from Baikonour using DNEPR LV on 29th June 2004 Sunsynchronous Orbit Inclination: 98° Altitude: 710-780 km Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

DNEPR LV Launch site

San Pietro in Vincoli (SPIV) Ground Station

Ground Station Operation Automation UNISAT-3 operation required one operator at the ground station 2hr/day at fixed times (sat in view) Remote operation Internet connection by authorized users (2hr/day in remote location) Full automatic operation, as programmed by the operator, about 10 min/week Gruppo di Astrodinamica dell’Università degli Studi “la Sapienza”

UNISAT-3 Real time Telemetry 3 solar array currents 3 solar array voltages 3 solar array temperatures 3-axes magnetometer measures Load and Battery currents Battery Voltage

UNISAT-3 Telemetry Data (2 July 2004) Temperature Data Voltage Data Magnetometer Data Current Data

UNISAT-3 Solar array test results (1)

UNISAT-3 Solar array test results (2)

UNISAT-3 Solar array test results (3)

UNISAT-4 UNISAT-3 Mission  Microsatellite Weight 10 kg Circular Orbit (Sunsynchronous , 750 km height) Structure  Geometry: octagonal prism (150mm side; 250mm height) Materials: Al + Al-Al sandwich Attitude  Passive magnetic Power  - Si and GaAs triple-junction solar cells - NiCd Batteries TLC  VHF (145 MHz) uplink; UHF (436 MHz) downlink; 9600 bps; UNISAT-3 Payloads  Langmuir Probe (CNR, IFSI)  2 COTS Camera with different resolution  Navigation experiment (GPS)  SIRDARIA (Spacecraft Integrated Re-entry Device Aero-Resistant, Increasing Area)  MPPT (maximum Peak Power Tracking)  COTS Magnetometers  GAUSS integrated Triple Junction Solar arrays

TPS: Triple Probe System Ionized particles densities are evaluated by voltages and currents among three electrodes exposed to the space plasma Probes Circuit

2 COTS cameras with different resolution Industrial applications camera Differrent resolution by appropriate COTS optics User programmable by simple “High level” visual programming block diagram environment 6x6 cm size 50g weight 1.5W power FOV and approximate ground resolution at 500 km height F 2,5 mm: FOV 84.6° image size 1000km resolution 1.4 km F 6 mm: FOV 36,8° image size 300km resolution 0.5 km

GPS receiver Channels 12 Position accuracy 5m Velocity accuracy 0.05m/s Cold Start 120sec (typ) Serial Interface 19200 bps Temperature -30° / 70°C Size 46x71x13 mm Weight 22g Power 0.5W NMEA or binary output format

SIRDARIA Spacecraft Integrated Re-entry Device Aero-Resistant, Increasing Area

COTS Fluxgate magnetometer Temperature -25 : 70 °C Weight 50 g Power 200mW Size 12x2.5 cm Serial interface Accuracy 5nT Alignment 0.2°

MPPT (Maximum Peak Power Point Tracking) Efficiency between 80% and 90% , depending on the working voltage Can recover damages of one or more solar cells in the solar array