Ariane 6 Completes Its Maiden Flight with Help from IDQ
On July 9th, Ariane 6 successfully embarked on its maiden flight from the Guiana Space Center. ID Quantique (IDQ) is very proud to be a part of this revolutionary project, which marks the first full industrial application of IDQ’s SNSPDs.
Ariane 6 incorporates revolutionary opto-pyrotechnics to achieve higher performance and substantial cost savings. This system includes IDQ’s ID281 SNSPD, Time Controller Series electronics, and Picosecond Pulsed Laser source. IDQ also provides ultra-high accuracy automatic ground test equipment to monitor the integrity and performance of the Ariane 6 fiber optic control system network.
IDQ’s Involvement in the Ariane 6 Program
In 2014 the Ariane 6 development program was launched in response to SpaceX’s aggressive commercial strategy with the objective for the European Space Agency to maintain a leadership position that was suddenly challenged. A cost saving target of 50% on every flight compared to Ariane 5 was set for Ariane 6. This should be achieved thanks to a restructured organization and several key innovations. One of the important technical innovations is the use of opto-pyrotechnics for the control of key phases of the launch.
IDQ has been involved in the program since 2017 to develop custom and high performance ground test equipment capable to perform integrity and performance monitoring of the entire fiber optic network of Ariane 6 control system’s associated with the opto-pyrotechnic system.
The Opto-Pyrotechnic System
The pyrotechnic control system onboard Ariane 6 is a technological breakthrough. The unique all-optical, fiber-optic-based, opto-pyrotechnic control and command system provides higher performance and significant cost-savings.
In space, pyrotechnic techniques are utilized in both launchers and satellites and are traditionally based on electro-pyrotechnic devices with primary explosives. Such devices are used to trigger the different phases of a flight, from ignition to booster and stage separation, and all the way to passivation and even mission neutralization.
The all-optical, opto-pyrotechnic system onboard Ariane 6 offers significant cost reductions in terms of integration and procurement, as well as a safer working environment on the assembly sites and launch pad. It uses high-power laser diodes connected to low-energy optical detonators via a fiber optic network. The devices are also relatively simple, very light, and compact, thus saving significant weight and costs, whilst providing highly reliable, near-instantaneous response with very little input energy. It is the first time opto-pyrotechnics has been successfully integrated and used on a European space launcher.
Fiber optics brings other important advantages. Optical fibers can be easily tested, for example their transmission performance can be accurately measured. And, they are totally immune to electro-magnetic perturbations.
One of the challenges encountered on Ariane 5 and previous programs is that the use of conventional electro-pyrotechnics requires very strict and complex safety measures, making the launcher assembly and testing phases hazardous, lengthy, and eventually very costly. The immunity of optical fibers to electro-magnetic perturbations greatly reduces the incident risk level, with fewer constraints regarding the access to sites.
The complex opto-pyro fiber optic network, several tens of lines with multiple connectors, needs be tested and verified, from the assembly of the rocket until the final tests on the launchpad a few days before the flight. This should be done automatically and possibly without human intervention.
Optical time domain reflectometry (OTDR) is an attractive technique for such test & measurement, as it provides integrity information, and insertion and back-reflection loss profiles, with high spatial resolution and event/failure localization.
The advantages of the Opto-Pyro Technique include:
- Reduced acquisition cost (fiber optic cables versus copper wires)
- Reduced total mass and volume
- Simple to handle and faster to install
- Immunity to electromagnetic interference (EMI) and electrostatic discharge (ESD)
- Safer, non-hazardous testing possibilities
But the measurement performance requirements imposed by the opto-pyro application are impossible to meet with conventional OTDR systems: centimeter scale spatial resolution, presence of multiple lossy connectors, free space optical safety barrier, quasi real-time measurement and strict limitation on laser power due to optical detonators at the end of each line. Sensitivity requirements are about two orders of magnitude higher than what commercially available OTDR systems can achieve.
And this is where IDQ got involved.
IDQ’s solution: Ultra-high resolution and autonomous OTDR-based integrity monitoring system
Since its inception ID Quantique (IDQ) has been involved in the development and application of single-photon detection and photon counting technologies and applications. Thanks to this unique expertise and know-how, IDQ was contracted by ArianeGroup in 2017 to develop custom and dedicated ground test equipment for integrity and performance monitoring of the Ariane 6 fiber optic control system network, based on a photon counting OTDR technique — the only option meeting ESA high performance requirements.
For this project, IDQ teams used IDQ’s ID281 SNSPD (Superconducting Nanowire Single-Photon Detector) as the foundation of the photon-counting OTDR system. The technology of IDQ’s Time Controller Series electronics and Picosecond Pulsed Laser source were integrated in the system to achieve the required sensitivity and spatial resolution, together with a multiple channel switch to automatically scan all the channels of the complex opto-pyro fiber optic network in a few seconds per channel. Control and analytical software was specially developed to both control the measurement and perform an analysis of the recorded, back-scattered profiles with respect to preset channel configuration, including attenuation thresholds by segment and back-reflection. The software enables automatic detection and localization of any abnormal loss, fiber attenuation, or back-reflection, documented in an automatically generated test report.
A complete multi-channel turnkey solution with control software features:
- Ultra-fast semiconductor pulsed laser
- Ultra low power laser requirement – 100 ps pulse width
- No risk of impacting opto-pyro system
- ID281 Superconducting Nanowire Single-Photon detection (SNSPD)
- Cryogenic SNSPD solution – 0.8 K detector operation
- High quantum efficiency and polarization insensitive
- Low noise (low dark count)
- Fast recovery time (limited to no dead zone)
- Photon counting and timing electronics
- Real-time control of the measurements
- Guaranteeing spatial accuracy of +/- 1 cm along all fiber optic sections
- Dedicated control software
- Automatic tests with performance analysis
- Self-generated test report
- Alarming of detected abnormal fiber conditions
The turn-key solution guarantees:
- End-to-end validation of the entire optical pyro-lines
- Quasi real-time measurement
- Automatic testing and performance analysis with no human intervention
- Ultra-high resolution (centimeter scale spatial resolution) and unrivalled dynamic range (>70 dB)
- Completely safe operation (zero risk with optical detonators)
- Real-time identification of integrity problems and system performance
- Fully compliant with drastic launch pad safety requirements
What were the requirements?
A turnkey solution with a measurement accuracy unachievable by traditional means (centimeter spatial resolution), integrating ultra-fast detection of integrity issues. The monitoring solution needed to be designed for automated tests with minimum to no human intervention and to provide automatically generated test report (pass/fail) with problem identification and localization.
What are the advantages of Single-photon technologies?
Single-photon detection, and here more specifically SNSPD, is the essential enabling technology for such high-performance OTDR as it provides the ultimate light detection sensitivity, high timing accuracy, short dead time, and a high dynamic range.
Where is the solution used?
The IDQ ground test equipment is used in Kourou, as well as in the different Ariane 6 assembly sites in Europe.
To request more information or a quotation for any ID Quantique products, contact IL Photonics.