Nanosat 01
| Company type | Nanosatellite |
|---|---|
| Industry | Aerospace |
| Founded | December 18, 2004 |
| Founder | Instituto Nacional de Técnica Aeroespacial (INTA) |
| Fate | Mission ended in 2009, replaced by Nanosat-1B |
| Headquarters | Torrejón de Ardoz , Spain |
| Products | Nanosatellite for communication and technology demonstration |
The Nanosat 01 was a nanosatellite created by Spain's Instituto Nacional de Técnica Aeroespacial (INTA) and launched on 18 December 2004. Weighing less than 20 kg, its chief objective was to enable communication between isolated sites such as the Juan Carlos I Antarctic Base and mainland Spain by utilizing a polar orbit at roughly 650 km altitude. Information gathered in Antarctica was transmitted during overhead passes and received when the satellite flew over the Iberian Peninsula.
Following the conclusion of its mission in 2009, it was replaced by the Nanosat-1B, another project developed by INTA.
Mission
Nanosat 01 functioned as an affordable technology demonstration satellite aimed at enhancing INTA’s capabilities in nanosatellite technology. It incorporated innovative magnetic and solar sensors, store-and-forward communication systems, and navigation instruments intended for space qualification in compliance with ASIC standards.
While in orbit, the satellite carried out four principal experiments:
- Verification of the Attitude Control Subsystem (ACS).
- Measurement of Earth’s magnetic field through a Sol–Gel nanosensor.
- Evaluation of solar sensors alongside power generation panels.
- Enabling worldwide communication using OWLS (Optical Wireless Links for intra-Satellite).
Body
The satellite’s structure consisted of a prismatic shape split into two hemispheres, each featuring a hexagonal base with six trapezoidal faces, collectively forming an approximate spherical form. Its dimensions spanned 600 mm from one base to the other, with a maximum radius of 540 mm. Almost the entire exterior was clad with GaAs/Ge solar panels mounted on aluminum panels affixed to the frame, producing an average power output of 17 W (peaking at 20 W). Lithium-ion batteries supplying 4.8 Ah allowed operation during periods without sunlight.
Access inside was achieved by detaching the two hemispheres, which were connected through a central hexagonal bus housing all subsystems. Essential elements included the OBDH (On-Board Data Handling) system responsible for spacecraft control and data processing, based on a DragonBall MC68332 microcontroller featuring 4 MB of storage, 8 kB PROM, 512 kB EEPROM, and 768 kB protected RAM; the PDU (Power Distribution Unit); RF communications components; and the ACS (Attitude Control Subsystem), which utilized solar cells and a magnetometer for attitude sensing and spin stabilization.
To minimize weight, INTA partnered with the ESA to develop OWLS, an optical infrared array designed to replace conventional electrical wiring for data transfer between modules. The final mass of the satellite was around 19 kg, with an expected operational lifespan of three years, although many subsystems functioned for four years.
RF communications
The RF communication system employed four omnidirectional antennas positioned on the top surface. Two different digital modems were evaluated: one based on a DSP chip and another utilizing an ASIC design. Communication operated via store-and-forward methods over the UHF band (387.1 MHz downlink, 400 MHz uplink) using GMSK modulation combined with Viterbi error correction. Ground stations accessed the satellite through a TDMA protocol incorporating Slotted Aloha, achieving data download rates up to 24 kbit/s. The system also featured capabilities for remote software updates.
Launch
On 18 December 2004, Nanosat 01 was deployed aboard an Ariane-5 G+ launcher from the Guiana Space Centre. It traveled as a secondary payload alongside the Helios-IIA satellite for DGA, four Essaim microsatellites, and the PARASOL mission.
The satellite was inserted into a Sun-synchronous orbit with an average altitude of 656.5 km, inclined at 98.1º, completing each orbit in approximately 97.7 minutes. Its radar cross-section was recorded at 0.2736 m2. Throughout its operational period, INTA conducted tracking and monitoring from its headquarters in Torrejón de Ardoz.
Attitude Control Subsystem
Given the satellite's configuration, which demanded limited precise attitude control—owing to omnidirectional antennas and solar panels covering the surface—the Attitude Control Subsystem (ACS) was designed to be straightforward. The ACS comprised six solar cells, a trio of electric motors equipped with magneto-coils, and an innovative compact sensor array built from Commercial Off-The-Shelf (COTS) components to reduce mass.
This sensor array incorporated two biaxial Anisotropic Magnetic Resistor (AMR) units mounted on redundant radiation-hardened printed circuit boards, complemented by photoelectric sensors. It provided moderate sensitivity near 3 mV/V/G and high resolution at 3 μG, functioning effectively within geomagnetic field strengths ranging from 0.1 mT down to 1 nT. The AMR setup utilized four Honeywell HMC1201 sensors arranged in a cubic formation, delivering a resolution of 1 mG while consuming less than 2 W and weighing only 0.22 kg.
During its mission, the ACS maintained the satellite’s spin axis perpendicular to the orbital plane with an anti-clockwise rotation at a controlled spin rate between 3 and 6 revolutions per minute. Weekly adjustments ensured position corrections to prolong operational lifespan.
Earth magnetic nanosensor
INTA engineered a magneto-optical compass leveraging the Faraday effect for precise measurement of Earth's magnetic field. At its core was a Sol–Gel Faraday rotor composed of rods containing γ-Fe2O3 nanoparticles smaller than 15 nm dispersed within an amorphous silica matrix. These rods were arranged inside a polarimetric dome featuring multiple polarizer layers that channeled LED light longitudinally through them. The magnetic influence on the nanoparticles caused rotation of the polarizers, modifying light intensity detected by photodiodes positioned at each rod’s end. The onboard data processing unit (OBDH) utilized this information to deliver highly accurate readings—down to 10 nT—of both satellite orientation and geomagnetic field strength.
The silica/γ-Fe2O3 composite was chosen for its combination of mechanical durability, excellent transparency, elevated Verdet constant, and superparamagnetic properties that prevent residual magnetism while enhancing optical measurement accuracy.
The sensor included compensation coils to adjust for variations in the Verdet constant caused by temperature fluctuations or wavelength shifts, along with a stabilized LED power supply; both features supported mid-mission recalibration. Measuring 20 mm in diameter and less than 5 mm thick, the device weighed approximately 200 g and consumed under 2 W.
This innovation resulted from more than seven years of joint development between the Instituto de Ciencia de Materiales de Madrid (ICMM, CSIC) and INTA. It represented the first application of Sol–Gel technology within aerospace manufacturing and contributed significantly to advancements in satellite miniaturization.
Solar sensors
Two distinct sets of photosensors—silicon-based solar cells and compact AsGa/Ge cells—were installed to assess their suitability for upcoming missions and to deliver accurate solar position information for spin stabilization purposes. The voltage output, ranging from 0 to 10 volts, from these sensors was directly proportional to the angle of sunlight incidence. Positioned in pairs of three along the satellite’s perimeter, their signals were analyzed to pinpoint the Sun’s location with an angular error margin of 5º due to nutation.
Although both sensor types shared the same input/output pathways and could not function simultaneously, an automated selection mechanism dynamically chose the most effective cells during operation.
Optical Wireless Links for intra-Satellite
Referred to as OWLS, this internal communication framework was created in collaboration with ESA to experiment with diffuse infrared data transfer and Bit Error Rate (BER) assessment in orbital conditions. Its core objectives included demonstrating wireless link functionality in space and investigating how environmental factors influence system reliability, representing the inaugural application of this technology beyond Earth. The system incorporated extensively adapted commercial hardware and concentrated on two principal experiments:
First Experiment
The initial test, OWLS-HNWLL, sought to establish a dependable connection between the On-Board Data Handling (OBDH) unit and the Attitude Control System (ACS), particularly targeting Honeywell magnetic sensors. It integrated infrared wireless communication alongside a backup wired line to cross-verify sensor outputs processed by the control unit. This arrangement also facilitated measurement of Single Event Transients (SETs)—brief voltage disturbances triggered by ionizing particles striking optical detectors.
The wireless network employed a Wavelength Division Multiple Access (WDMA) design, featuring a photodiode receiver with sensitivity at 700 nW/cm2, an active area of 25 mm2, and a bandwidth of 1.5 MHz. The optical emitter provided a peak power output of 15 mW.
Sensor data were converted via Voltage-Frequency (V/F) modules into pulse sequences transmitted over fixed time frames, where pulse counts represented signal intensity. An additional simulated zero-output line was used to distinguish authentic sensor signals from SET-induced noise, thereby enhancing comprehension of ionizing radiation impacts and improving noise filtering techniques.
Second Experiment
Termed OWLS-BER, the second trial evaluated a closed-loop optical link on the On-Board Computer’s SPI bus. Data pulses emitted optically were diffused off the satellite’s internal surfaces and captured by a receiver. The OBC then compared received information against computed BER metrics.
This test utilized an independent FDMA channel operating at 4 MHz with ASK modulation, enabling ground stations to monitor performance and partially filter interference at transmission speeds of 100 kbit/s and 100 kbit/s.