Calnetix Technologies Supplies Key Components for NASA’s Next-Generation CO2 Removal System

Calnetix Technologies has designed and developed a high-speed in-line blower and a dual controller for NASA’s next-generation CO2 removal system. The design and development of the Four Bed Carbon Dioxide Scrubber (4BCO2) is being led by NASA and is planned for installation on the International Space Station (ISS) after rigorous ground testing at its facilities.

Calnetix was responsible for the development of the blower assembly, which includes a compact in-line blower on magnetic bearings, called Momentum™, and an integrated hybrid dual controller, called Continuum™, to drive the blower. The magnetically levitated in-line blower is an integral component of the CO2 removal system and will drive the airflow through the entire system in a microgravity space environment.

Calnetix’s Momentum In-line Blower features an overhung permanent magnet motor, a centrally located five-axis active magnetic bearing (AMB) system, backup bearings and an overhung centrifugal impeller in a very compact package. Magnetic bearings were used instead of conventional bearings due to their low transmitted vibration, high-speed levitation, low power consumption, high reliability, oil-free operation and tolerance to particle contaminants in the air stream.

Calnetix’s Continuum Dual Controller consists of an AMB controller and a variable speed drive (VSD) motor controller in a single compact package that supports speeds up to 60,000 RPM with long-term maintenance-free operation. Calnetix’s AMBs were utilized to eliminate lubrication and rotating drag losses, which was an important aspect in meeting NASA’s stringent outgassing requirements.

In order to meet the application needs, the in-line blower system has the following features:

• Must survive launch vibrations and acceleration requirements

• Complies to electro-mechanical and power quality requirements under NASA SSP 57000

• Must be designed to have a shelf life of 15 years

• Must operate 30,000 hours without requiring maintenance

• Must operate with very low conductive and convection cooling availability

• Bearings used cannot introduce contaminants, such as lubricants or grease into the airstream

• Blower must be able to tolerate the ingestion of particles, such as particles liberated from the filter media and dust in the cabin air without incurring damage

The main design challenge was to fit the new magnetic bearing blower into the same space as the foil bearing supported heritage blower, which is currently being used on the ISS. The AMB system with position sensors and backup bearings had to be miniaturized to fit into a highly constrained space. In order to create a compact design, the bearing system was centrally placed to be used with a centrifugal impeller positioned at the air inlet and an overhung permanent magnet motor at the outlet side of the machine. The air flows through an annular passage around the internal components.

“Having passed NASA’s rigorous testing, the 4BCO2 blower system is an important validation of our patented permanent magnet motor, magnetic bearing and new controller technologies,” said Vatche Artinian, CEO of Calnetix Technologies. “The flight hardware components supplied by Calnetix met all the critical design, performance, interface and environmental requirements for a compact and robust blower system. This is the first time a commercial technology of this kind has been qualified for aerospace and flight application.”

Upon successful use of the magnetic bearing blower on the ISS, magnetic bearings could also be used in other aerospace applications, such as fluid pumps, reaction wheels and gyroscopes that challenge conventional bearing technologies.