By Ivan Kesic
The launch of the Nahid-2 satellite marks a significant milestone in the advancement of Iran’s national space, satellite, and telecommunications technology, as well as the deepening of space cooperation between Tehran and Moscow.
On Friday, the domestically built research and telecommunications satellite was successfully launched into a 500 km orbit aboard a Soyuz-2 rocket from Russia’s Vostochny Cosmodrom.
Nahid-2 was developed by the Iranian Space Research Institute, whose head recently announced the satellite’s readiness for launch.
The project aligns with Iran’s broader space program, which includes the upcoming Pars 2 satellite and the Pazhoohesh satellite series.
The successful deployment of Nahid-2 enhances Iran’s telecommunications infrastructure and demonstrates its growing technological self-reliance despite international restrictions.
It also reflects a strategic partnership with Russia, which has provided launch services and technical support, particularly as Iran faces US sanctions that limit its access to Western space technology.
The Soyuz-2 rocket, a reliable workhorse of the Russian space program, carried Nahid-2 alongside other payloads, reflecting growing Russo-Iranian space collaboration.
This follows previous successful launches of Iranian satellites via Russian rockets, such as the Kowsar and Hodhod satellites in November 2024.
On the same day it was launched, the Iranian Space Agency (ISA) announced that it had received the first telemetry data from the Nahid-2 satellite.
What are the technical characteristics of Nahid-2?
The Nahid-2 satellite is a telecommunications microsatellite designed for telecommunication missions in low Earth orbit (LEO), generally defined as an altitude between 160 and 2,000 kilometers.
It serves as a platform for developing and testing sensitive subsystem technologies that could be applied to future geostationary orbit (GEO) telecommunication satellites, at an altitude of approximately 35,786 kilometers.
The satellite is cube-shaped, with an edge length of 64 centimeters, and is powered by solar arrays mounted on its body, ensuring sustainable energy in space.
The cross-shaped structure, optimized for a high strength-to-weight ratio, incorporates an isolator to minimize vibrational loads. This innovative design has significantly reduced the satellite’s overall structural weight, even though its components are high-density.
Furthermore, a custom-built trolley with specialized features, including rotation around coordinate axes and an integrated isolator to mitigate transportation-induced loads, has been developed specifically for this satellite.
The thermal control subsystem of the Nahid-2 satellite comprises multi-layer insulation, colored coatings, heaters, sensors, washers, liners, and a thermal control board.
Given the risks posed by extreme temperature fluctuations in chemical propellants, such as freezing or overheating, this subsystem plays a critical role in ensuring satellite safety.
Strategically placed heaters maintain optimal temperatures for both the propellant and pressurant tanks. Additionally, thruster zones experience substantial heat buildup, which is managed through dedicated heat shields.
The satellite’s power subsystem integrates gallium arsenide solar cells with a lithium-ion battery to deliver an average power output of approximately 35 watts. Its solar arrays consist of four body-mounted panels constructed on honeycomb substrates.
All power electronics, including charger boards, power switch boards, power relay boards, main and auxiliary converters, and power distribution boards, are consolidated within a dedicated power electronics box, ensuring efficient and reliable operation.
As one of Nahid-2’s missions is to demonstrate chemical propulsion technology and execute orbital maneuvers, the satellite has been equipped with a dedicated propulsion subsystem capable of performing an orbital transfer from 500 kilometers to 550 kilometers altitude.
The system utilizes chemical propulsion with a thrust level of 1 Newton, incorporating four active thrusters and four redundant backups.
The development and structural integration of this single-component chemical propulsion system mark a pioneering achievement in the nation’s satellite manufacturing capabilities.
To study the space radiation environment, the satellite carries a dedicated dosimeter payload designed for LEO operations. This instrument will measure radiation exposure levels at approximately 500 kilometers altitude over a three-year period.
The collected data will provide valuable information about radiation intensity and type, helping engineers design more robust satellites for future missions.
The Nahid-2 satellite has two primary mission objectives: demonstrating orbital transfer capabilities using mono-propellant propulsion technology and validating a two-year operational lifespan in low Earth orbit.
These core technology developments are complemented by several secondary experimental objectives, including GPS-independent radio positioning tests, attitude control verification using store-and-forward telecommunication propulsion, in-orbit radiation dosimetry measurements, and simultaneous multi-channel telephone communication experiments.
This mission architecture combines critical space technology validation with valuable secondary payload operations to advance domestic satellite capabilities.
What are the satellite’s command and control areas?
Nahid-2 satellite employs a robust communication architecture utilizing multiple frequency bands. Its primary telemetry and telecommand operations are handled through dual S-band links (main and auxiliary).
For positioning data transmission, the satellite uses a VHF-band link that additionally serves as a secondary telemetry downlink. The communication suite also includes an S-band ranging signal transmitter for precise radio positioning.
Complementing these systems, the UHF-band uplink dedicated to the store-and-forward payload functions as a secondary telecommand channel, ensuring redundant command capabilities.
The Attitude and Orbit Control Subsystem (AOCS) represents one of Nahid-2’s most critical systems, delivering three-axis stabilization with exceptional 1-3° RMS pointing accuracy in all axes.
This sophisticated system combines multiple sensor technologies, including sun sensors, magnetometers, and rate gyros for precise attitude determination, with magnetic torquers and reaction wheels for active control.
Custom-developed control algorithms optimize these components to achieve maximum pointing accuracy for the satellite’s mission requirements.
Prior to deployment, the subsystem successfully completed all verification phases, including Software-in-the-Loop (SIL), Processor-in-the-Loop (PIL), and Hardware-in-the-Loop (HIL) testing, validating its operational readiness for the Nahid-2 mission.
Nahid-2’s command and data handling (C&DH) architecture features redundant onboard computer (OBC) boards (primary and backup) along with a dedicated supervisor board, all housed within the satellite’s electrical enclosure.
The subsystem’s core processing capability is built around Microsemi’s radiation-hardened SmartFusion2 FPGA, which offers several critical advantages, like flash-based fabric architecture providing inherent single-event upset (SEU) immunity.
Furthermore, it provides additional memory protection through error detection and correction (EDAC) and triple modular redundancy (TMR) techniques.
For redundancy management, the supervisor board utilizes Microsemi’s ProASIC3 chip, selected for its exceptional combination of ultra-low power operation and high reliability – essential characteristics for mission-critical spacecraft systems.
The telephone signal relay telecommunications payload serves a dual-purpose strategic function. Its primary operational objective is to enable direct communication links between ground stations within mutual visibility using Ku-band frequencies.
This capability represents a critical first step in Iran’s space technology roadmap, establishing the fundamental infrastructure and expertise necessary for future development of geostationary telecommunications satellites.
By demonstrating successful signal relay operations in low Earth orbit, the mission provides both technical validation and operational experience that will directly support the nation’s ambitions for more advanced GEO communications systems.
The store-and-forward payload enables satellite-mediated UHF-band communications for a network of 254 ground users. This system implements an innovative communication protocol that represents a world-first technological achievement in satellite communications.
By utilizing this novel approach, the payload establishes a unique relay capability that significantly enhances connectivity options for ground users while demonstrating cutting-edge advancements in satellite communication architectures.
The Nahid-2 satellite’s multiple communication links require an extensive network of ground stations to maintain reliable operations.
The system includes six fixed-location stations, one mobile station, and portable units, all capable of operating across KU, S, X, VHF, and UHF frequency bands. This distributed network ensures continuous communication support for the satellite’s various functions.
