3u satellite

Space Inventor’s 3U satellite is configured from our modular subsystems, which provides the opportunity for buyers to tailor the satellite exactly to their needs. Our highly iterative development process secures an easy and safe integration procedure and provides the opportunity for module interchangeability. This procedure, which is seen across all Space Inventor platforms, relies on thorough analysis as well as subsystems that are updated at least once a year. The 3U satellite is built with shielded hi-reliability subsystems where each system has its own radiation shielding, EMI Shielding, thermal conduction path, and mechanical support.

The 3U satellite platform has deployable solar panels which provides power for the whole platform. The attitude determination and control system is capable of optimizing the satellite’s attitude for maximum sun power input while maintaining accurate payload pointing direction.

The 3U satellite platform has deployable solar panels, which enable missions with high power requirements.

All Space Inventor satellite platforms has a minimum lifetime of 5 years.

Applications of Space Inventor’s satellite platform:

  • Educational missions
  • BIU missions
  • In-orbit demonstration missions
  • Scientific missions
  • IoT missions
Payload Mass
1.5 - 2 kg
Payload Volume
1.5 - 2 unit
Payload power
100 W
Data downlink
2x S/X band 4 - 200 Mbps
1x gas or ion
Flight Heritage

Subsystems in Space Inventor’s 3U satellite


The satellite platform is designed by using the high reliable subsystems made by Space Inventor providing high performance, low EMI and very easy integration.  The basic avionics consists of four basic elements, the power plant for power generation, conditioning and distribution, on-board data handling, communication to ground segment and the attitude determination and control system.

The satellite platform is designed with reliability and performance as the primary design drivers. It uses the shielded hi-rel subsystems: Batteries, power conditioning and distribution, communication and attitude control. Each system has its own radiation shielding, EMI shielding, thermal conduction path, and mechanical support. The satellite is designed not only for extreme ruggedness but also ease of integration. Any side panel can easily be removed and are then free with no cables attached.

Power Plant


The complete Space Inventor power systems suite consisting of the MPPT-P3, BAT-P3, PCDU-P3 is providing an agile and effective solution. The power systems provide all functionalities needed from maximizing power input from the photovoltaic cells, storing power and providing regulated output channels to individual subsystems. On the output side an unregulated V-bat is also available. On Space Inventor’s 3U satellite solar cells are typically laid down on a flex PCB substrate designed to each particular mission with the number of cells needed. Space Inventor uses a minimum harness approach where the power harness is integrated into the structure and the solar panels can be disassembled from the structure without disconnecting power harness. Power is routed through the DISE system mounted on the side panels through the bottom plate to the MPPT.

  • Solar panels – deployable and/or body mounted
  • Maximum power point tracking (MPPT-P3)
  • Battery pack (BAT-P3)
  • Power conditioning and distribution unit (PCDU-P3)


The MPPT-P3 is a 7-channel maximum power point tracker and battery charger module, designed to condition the power delivery from satellite solar panels to the battery in order to achieve maximum efficiency. The system consists of six variable frequency DC-DC buck converters and a single variable frequency boost-converter, that ensure optimal operating voltage for each solar cell array at all temperatures and irradiance levels. After conversion, the channels are combined through ideal diodes to minimize loss, and connected to the battery output.

A configurable end-of-charge setting will stop charging at a certain voltage level in order to prolong battery life. When components reach end-of-life, a pass-through mechanism will route the solar output directly to the battery bus, whereby functionality is not entirely lost. Likewise, if the on-board MCU is disabled, each MPPT channel has a fixed voltage fallback. Housekeeping data for all channels are available through CSP telemetry. Appreciating that the solar panels are often combined with external sun and temperature sensors, each solar panel connector are equipped with a protected battery supply and CAN bus interface.

The MPPT-P3 is built for durable, simple and robust satellite integration


  • Maximum power point tracker for satellite solar panels
  • Integrated battery change management
  • 7 solar cell string input channels w. Up to 2 x 12 cells per channel
  • Ruggedized enclosure for maximum thermal performance, radiation shielding and EMI reduction
  • Suitable for microsatellites and CubeSats
  • Measurements: (L, W, H) 91.14 x 94 x 11 mm // 150 g


The BAT100-P3 is an 8 cell Lithium-Ion battery system designed for high battery life-time, easy integration, and safety. The battery configuration can either be 4s2p or 8s1p providing 92 Wh in nominal capacity. The BAT100-P3 is both flexible enough and sufficiently powerful for most nano- and small-satellite missions. The automatic balancing circuit maximizes cell lifetime, and the automatic heater keeps the cells operational at low temperatures. Short-circuit and over/under voltage circuits protects the cells from damage.

To accommodate different launch vehicle requirements, each module has connectors for both soft and hard inhibits. The BAT100-P3 comes in a rugged and modular 1.5 mm Al enclosure, which both acts as on-orbit radiation mitigation as well as a practical short-circuit protection during satellite assembly. An always-on ultra-low-power Real Time Clock provides timer-continuity during satellite shutdown.


BAT100-P3 features

  • Integrated battery module for satellites
  • 8 LiIon cells configurable for 14.4 or 28.8V at 92 Whr
  • Cell balancing and heater
  • input/output current limiting
  • Ruggedized enclosure for maximum thermal performance, radiation shielding and EMI reduction
  • Suitable for microsatellites and cubesats
  • Measurements: (L, W, H) 91.14 x 94 x 41.2 mm // 655 g


The PCDU-P3 is a twelve-channel power conditioning and distribution unit in a rugged, compact and modular enclosure. The system features six independent and customizable step-down converters and one boost converter, that can be connected to output channels as required. The PCDU-P3 architecture allows designers to allocate one subsystem per power channel, whereby many of the EMI issues experienced on shared power busses are eliminated. This makes the PCDU-P3 ideal for missions with demanding payloads and sensitive receivers.

To minimize thermal stresses and mitigate radiation, the PCDU-P3 is enclosed in 1.5 mm (min.) Al. The PCB is top-side only and mounted flush with the bottom of the enclosure, which reduces thermal resistance to the satellite body. With a standing height of only 12 mm and PC104 compatible mounting holes, the PCDU-P3 easily integrates with existing busses, without occupying excess stack space. All outputs have independent power monitoring and latch-up protection. Monitoring and configuration is enabled through the CSP protocol and onboard MCU. For convenience all connectors are CAN enabled.


PCDU-P3 features

  • Power conditioning and distribution unit for satellites
  • 12 power output channels with protection and monitoring
  • 6 buck converters and 1 boost converter with configurable voltages and routing
  • Power metering, latch-up protection, battery discharge management and protection, programmable on/off timers
  • Ruggedized enclosure for maximum thermal performance, radiation shielding and EMI reduction
  • Suitable for microsatellites and CubeSats
  • Measurements: (L, W, H) 91.14 x 94 x 13 mm // 138 g

Attitude Determination and control system


Space Inventor’s attitude and orbit determination and control solutions are comprised by our wide range of high-performance, rugged and modular AOCS avionics products. The range of modules spans from very small cubesat reaction wheels to large reaction wheels for satellites up to several hundred kilograms. Furthermore, we manufacture a best-in-class star tracker, integrated fine sun sensors, magnetorquers, GPS modules, ADCS computers and software which we use to configure tailored ADCS and AOCS solutions for both simple cubesats and highly advanced science satellites.The ADCS system can provide Nadir or Ground Target tracking mode and can be tailored to the specific orbit and mission.

  • Includes fully featured ADCS software
  • Pointing modes include: Nadir, sun tracking, ground spot tracking, inertial pointing, dual target (e.g. nadir while sun tracking)
  • Actuators: 4 reaction wheels, redundant magnetorquer rods
  • Sensors: 5 fine sun sensors, 5 gyroscopes, 5 magnetometers
  • Performance: 1 degree pointing accuracy
  • The software runs on the redundant OBC-P3

Momentum Wheels

Space Inventor’s 3U satellite uses a fully integrated reaction wheel unit for high performance satellite attitude control with mission lifetime of 5 years (minimum). The WHL-10 wheel is an integrated 3-phase outrunner Permanent magnet synchronous motor (PMSM) with 8 rare-earth magnet poles in the rotor and 6 teeth in the stator. Material for the body is Al-7075-T6, rotor is made of ferritic stainless steel while the magnets are Neodymium.

The rotor is axially suspended between two hybrid ceramic high precision bearings chosen for long life and low friction in vacuum conditions. The wheel is commutated by its own internal microcontroller, which runs the control loop to control speed and acceleration upon commands from the ADCS computer.


Wheel-10 Features

  • Compact, integrated reaction wheel unit for 1-3 kg CubeSats
  • Momentum storage of 10 mNms @ 20.000 RPM
  • Torque 2 mNm
  • Control: Momentum, torque, speed or motor voltage
  • 3-phase Permanent magnet synchronous motor (PMSM)
  • Can bus interface with CSP
  • Rotor inertia: 5 x 10-6 kg mm2
  • Measurements: 30 x 30 x 21 mm // 59 g


The highly integrated Fine Sun Sensor (FSS-1G2), integrated in an advanced 1U satellite, uses four photodiodes to estimate the sun direction vector with a precision of 1 degree. The module has a built-in micro controller which enables connectivity to a CSP network via CAN bus and readily integrate with an attitude determination and control system such as e.g. ADCS-P3 and ADCS-R3. In addition to the sun sensor functionality, the module includes a 2-axis gyroscope and 3-axis magnetometer making it a versatile attitude sensing component. The 1G2 variant is an upgraded version of the previous 1G model which has flight heritage. 1G2 is expected to be launched in Q1 2022.


FSS-1-G2 Features

  • 2-axis sun direction sensor based on quad photo diode array
  • 1 degree precision
  • 55 degree half-cone FoV
  • Integrated 3-axis magnetometer
  • 0.25mG per LSB resolution
  • 0.4mG total RMS noise
  • Magnetic field direction accuracy 1º
  • Integrated 2-axis Gyro
  • Ultralow noise: 0.004°/s/√Hz
  • 5-28V unregulated power input
  • Data interface: CAN bus with CSP2.0
  • Measurements (L, W, H): 40x20x10 mm



The communication system consists of a VHF/UHF TT&C radio for telemetry and commanding the spacecraft. The radio system can be configured to different operating frequencies according to the frequency license obtained from ITU for space operation. A high data-rate radio in S-band (STTC-P3) can also be included in the configuration with a patch antenna mounted on face pointing Nadir.


  • UHF/VHF radio (TTC-P3)
  • UHF/VHF antenna (DMA)
  • S and X-band transmitter (STTC-P3)


The TTC-P3 is a hot-redundant satellite telemetry, tracking and command (TT&C) radio with two half-duplex VHF/UHF transceiver designed to enable robust and reliable satellite communication. The TTC-P3 is intended to be used in an antenna diversity scheme, where each channel is connected to orthogonal and cross-polarized antennas. Hereby a good omnidirectional gain pattern can be achieved, which makes signal reception nearly independent of satellite attitude. Careful receiver design provides a noise figure below 2 dB, which, combined with concatenated convolutional and Reed-Solomon decoding, ensure excellent sensitivity. Realizing that interference have proved problematic over certain regions, the TTC-P3 also features a 60 dB out-of-band rejection filter.

TTC-P3 features

  • 2 Half-Duplex VHF/UHF Transceivers
  • Data-rate: 4800 – 38400 kbps nominal (up to 115.200 available upon request)
  • Frequency bands: 130-140,140-150, 400-410 and/or 430-440 MHz
  • 30 dBm output power at > 50% PA efficiency
  • Noise Figure: <2 dB
  • Modulation: GMSK
  • FEC: Convolutional Coding (K=7, r=½) and Reed Solomon (RS-223,255)
  • Measurements: (L, W, H) 91.14 x 94 x 11 mm // 143 g


The STTCX-P3 is a software defined satellite transceiver offering a versatile S/X-band transceiver module for high-speed communication and ranging solution for both LEO and GEO missions. The transceiver is designed to work with the latest CCSDS Cat A recommendations for high data rate transmissions and high spectral efficiency. Using constant envelope GMSK or low crest factor SRRC filtered OQPSK modulation for higher power amplifier efficiency and lower linearity requirements.

The ranging functionality supported is transparent pseudo noise ranging according to CCSDS 414.0-G2 standard where the transceiver frequency-translates the uplink ranging signal to the downlink without code acquisition (i.e., non-regenerative ranging or turnaround ranging) – Eventually active regenerative ranging system will be supported The SDR is based on a powerful Xilinx Zync-7030 SoC and high-performance Analog Devices SDR front-end, the AD9361.


 STTCX-P3 features

  • Channels: 2 receive, 2 transmit
  • 2 x S-band uplink : 2025 – 2110 MHz
  • 1 x S-band downlink: 2200 – 2290 MHz
  • 1 x X-band downlink: 8025 – 8400 MHz
  • Tx power up to 2 Watt
  • Rx noise figure: 5 dB (TBD)
  • Full duplex
  • Tx amplifier bypass function
  • CCSDS compliant (401.0-B-30)
  • GMSK or OQPSK – 9600 bps to 20 Mbps
  • FEC: Convolutional Coding (K=7, r=1⁄2) and Reed Solomon (RS-223,255)