The 22^nd of March, 2021 at 06:07am (UTC), GK Launch Services has launched Soyuz 2.1 rocket from Baikonur Cosmodrome.

The launcher has deployed a Fregat upper stage in space, and fired its engine several times over four hours to inject 38 small and medium-size international satellites into three different orbits.

On these 38 satellites, two of them are equipped with THERMOCOAX heating systems dedicated to activate the chemical propulsion.

One of the satellites is dedicated for space debris clean up. The other one is dedicated for imagery with electro-optical sensor in it for earth observation.

These heating systems are designed, developed and produced in our factory of Normandy, France. THERMOCOAX has 15 years heritage. Most of the application are:

• Catalyst Bed heater for chemical propulsion
• Magnetic coils and high temperature cabling for electrical propulsion
• Rod heater for payload temperature control (Mechanical Pump loop )
• Heating coils for actuators based on SMA technology (pyrotechnic free)THERMOCOAX success is based on the motivation and passion of his all employees plus of course, on the unic home made mineral insulated cable.

The cable offers small dimensions, flexibility, ability to withstand 1000°C and more with exotic material.

This technology has already demonstrated 15 years on board GEOSatcom with more than 15 000 devices.

THERMOCOAX is currently travelling on March with Curiosity for dust samples treatment and will be soon again with EXOMARS program on the landing propulsion system.

THERMOCOAX is pushing its technology on chemical propulsion to make it more efficient and proposes innovative solutions for the electrical propulsion. Some last developments are under qualification and dedicated for the thermal management of high energy intensive 100 volts plateforms.

Two satellites are equipped with catalyst bed heater systems for chemical propulsions.

Since more than 10 years, THERMOCOAX is supplying innovative heating systems for the chemical propulsion, green and hydrazine.

More than 200 catalyst bed heaters are flying currently successfully.

These propulsions are used several times per day for altitude, trajectory and orbit control.

New designs of catalyst bed heater with fast heating ramp-up are now qualified and aim debris avoidance and under demonstration for debris removal mission.

THERMOCOAX equips with magnetic coils and heating systems to make the platform more reliable and 25 years service life.

The Challenge

Space platform request magnetic coils to produce the thruster of the engine to travel to final orbit and then keep the satellite on the orbit during all his life.

The customer system was looking for component withstand high temperature and long reliability (25 years).

Heating system is used to avoid the engine to rech too low temperature. By this, the engines are fully operational at full power when activated.

These systems need to be fully proven by strict tests and qualifications program. Heavy document have to be provide for a full traceability of the components and production.

The Solution

Based on our homemade mineral insulated cable and our high level of engineering, production and quality management, we design and produce dedicated final systems ready to be mounted on the propulsion system.

Choosing electrical propulsion increases the service life of the satellite, means more value for the OEM and more service for the satellite operator.

In pratice, electrical propulsion saves 10 to 15% of volume replaced by payload used for datas that the operator sell to his customers.

You are looking to replace your pyrotechnic actuators with shape memory alloy technology for your space applications ? We have the most advanced industry-proven solutions.

Spacecrafts require variety of mechanisms to accomplish the mission. The typical functions are deployment, articulation, positioning, displacement.

Pyrotechnic separation nuts, paraffin actuators and others devices are hazardous for the satellite, regarding shocks waves generation and potential risk of contamination.

Shape Memory Alloy ( SMA ) technology equipped with inner heating element, offers smooth and slow behavour, higher cleanliness result and good vibration & shock resistance.

Thermocoax addresses this new market with miniature and powerfull heating element, same components already demonstrated on propulsion and thermal management on board satellite.

Main applications are single one time used valve, Hold Down & Relieve Mechanism (HDRM), Pin Puller, deployment Hinge.

[showhide type=”links” more_text=”To receive the entire White paper on SMA application please click here” less_text=”Hide”]

Heating coil

THERMOCOAX supports the 100 volt Satcom new generation. First European full electrical propulsion satcom produced by Airbus D&S.

On-board EUTELSAT 172,  THERMOCOAX provides the propulsion’s heating rings (attitude & orbit control) + the 100 volts heating elements mostly used during the transfer orbit.

Launching’s planned next June, from French Guiana Space Center.

Spacecraft Propulsion

Coiled cable design for :

Green propulsion : Thrusters 1 to 200N

Deorbiting operation : Thruster 400N

Thermocoax Pedigree

THERMOCOAX has been a key player worldwide for 15 years in the designing, developing and manufacturing of heating systems for the space market.

We provide solutions for:

– Ground applications:

• R&D programs with institutes
• Ground equipment

– Flying models :

• Heating management system on Satcom.
• Catalyst bed heater for chemical propulsion
• Heating solution for Hall Effect thruster

-Scientific Mission :

• Heating system on Curiosity Rover
• Heating Element on ISS for MSL
• Heating Element for pyrolysor on Cassini-Huygens Titan probe

Technical Application of Coiled Catalyst Bed Heater

The new generation of Green propulsion thrusters and deorbiting thrusters is a great opportunity to supply the market with a new generation of catalyst bed heater for better efficiency, increased reliability and greater cost-effectiveness.

Until now, the cartridge design heater has been mostly used and 2 to 4 systems are implemented on the thruster to reach 12 watts.

THERMOCOAX is able to simplify the catalyst bed heater system by offering its technology solution of a heating cable which has a diameter of only 1 mm. This cable is then coiled around the catalyst and fixed by brazing or another fixation mode.

This new design is based on long-proven cable technology that has been adopted by aircraftavionics and space missions, such as for the Prisma spacecraft. Currently, this new design is qualified to equip the 40-satellite constellations dedicated to taking 3D pictures of the Earth.

Technical Description of the Catalyst Bed Heater

We use our best mineral insulated cable.

Mineral Insulated Cable with 4 resistive wires to shape 2 heating loops

Cold part in two stages, the first stage with a diameter of 2.3mm, the second stage with 1.5mm and a heating part with a 1mm diameter

The cable is then coiled around a ring to be fixed onto the catalyst.

Example 1 :

Example 2 :

Catalyst Bed Heater :

• 2 redundant electrical loops
• Nominal Power supply: 28 volt to 55 volt
• Power version per loop :
  • 10 watt under 28Vdc
  • 100 watt under 55 volts
• Max exposed temperature :
  • 1000 °C with Inconel
  • 1600°C with Platinum

Other power available by playing on the cable geometry :

Mineral Insulated Cable :

Version exposed 1000°C :

• Inconel 600 sheath
• 4 Nickel-Chromium wires

Version exposed 1600°C

• Platinum sheath
• Platinum-rhodium wires

Lead Wires :

• 4 wires
• Color code for each loop
• AWG24 or 26
• Strength 1.4 kg

Acceptance Test Criteria of the catalyst bed heater :

• Helium Leak Test
• X-Ray of the heating cartridge
• X-Ray of the MIC/lead wires junction
• Lead attachment strength test
• Visual and mechanical examination
• Overvoltage
• Line Resistance
• Insulation Resistance under 500volts
• Burn-in test
• Dielectric 100/300/500Vac, 60Hz/60s
• Weight
• Final Manufacturing Report

Test List for Qualification Program of the Catalyst Bed Heater

• Thermocoax conducts and realises the qualification test program in accordance with our customer’s specifications.

Our engineers write the QTP for customer approval prior to test execution.

Most of the tests (thermal, humidity, electrical…) on the Catalyst Bed Heater are performed in THERMOCOAX’s testing lab facilities.

Those requiring heavy equipment (vibration, acceleration, shocks…) are subcontracted to external laboratories or supported by our customers with the complete propulsion system.

-Typical Qualification Test list on Catalyst Bed Heater :

• Vibration
• Acceleration
• Mechanical shock
• Pyrotechnic Shock
• Helium leak test
• Burn-in test
• Humidity test
• Hot Firing test
• Electrical Cycling test
• Thermal cycling test
• Lead Attachment Test
• Dielectric Test
• Destructive Physical Analysis
• X-Ray Examination

• Packaging and Cleanliness :

The Catalyst Bed Heater is shipped in a specific packaging to ensure excellent conditions during transportation and storage :

Thermocoax supplies new green propulsion programs (1, 5, 20, 200 and 400 Newton thrusters). Here are few examples :

• Prisma
• Google Constellation

THermocoax is the market leader in Catalyst Bed Heater production and is proud to participate in challenging international space programs.

THERMOCOAX focuses on high quality Catalyst Bed Heater products for the best stability and repeatability during operation. For 15 years, we have witnessed the challenges faced by our customers to manufacture spacecraft and to improve the quality of life of humanity.

New large constellation programs are taking shape, THERMOCOAX is now ready to support the market with cost-effective catalyst bed heaters.