ESA Demos MEMs Rocket Thruster That’s as Small as a Coin

With the continued miniaturization of electronics and growing accessibility of orbital launch capability, small satellites have been experiencing quick progress. Nevertheless, it’s not simply the electronics that should shrink.

Thruster and different stabilization gear should additionally drop proportionally in measurement. Whereas particular function satellites maintain getting smaller, key parts, similar to thrusters haven’t saved tempo with downsizing.

Conventional thrusters use hydrazine rocket gasoline, which requires tankage along with the engine and management techniques. Newer ion and electrical propulsion techniques have been launched or are beneath improvement, however they’re nonetheless too giant to be an efficient answer for the smallest two satellite tv for pc classes: Nano satellites, that are between 1 and 10 kg (2.2 to 22 lbs.) and Pico satellites, which weigh between 0.1 kg and 1 kg (0.22 to 2.2 lbs.).


ICE-Cube thruster designed for nano satellites.

ICE-Dice thruster designed for nano satellites. Picture courtesy of ESA


The ESA (European Area Company) has now tested a micro rocket thruster geared toward Nano and Pico satellite tv for pc purposes. It was designed by a staff at The Imperial School of London. The brand new thruster, dubbed ICE-Dice (Iridium Catalysed Electrolysis CubeSat Thruster), makes use of electrolysis to separate hydrogen and oxygen out of water.

It then recombines the gasses in a combustion chamber lower than 1 mm in size. So small, the truth is, that it requires use of a MEMs fabrication process. The thruster has been demonstrated, in laboratory exams, to ship 1.25 millinewtons thrust at a particular impulse of 185 seconds sustained.


The Small Satellite tv for pc Race

Nano satellites are a comparatively new however quick rising class of area car. Simply 25 have been launched in 2012. A decade later, 334 have been launched in 2022 and almost double that quantity have been introduced for launch in 2023.


Nano satellite.

Nano satellite tv for pc. Picture courtesy of NASA


These satellites have little room to spare. The necessities for tankage of typical poisonous and corrosive propellants, similar to Hydrazine shortly turn out to be impractical. Different small scale types of propulsion like ion, compressed air or steam will not be as vitality environment friendly as a hydrogen + oxygen combustion system. Many don’t give ample lifetime when restricted to Nano satellite tv for pc measurement.


Recombining Hydrogen and Oxygen for Thrust Era

Storing the propellant within the type of water ice is safer and less expensive than holding it as gaseous or liquid gasoline kind. The electrolysis course of makes use of simply 20 Watts that may be generated by way of photo voltaic cells and or storage batteries. In a way, the machine converts photo voltaic vitality into thrust by means of ice.


ICE thruster in action.

ICE thruster in motion. Picture courtesy of Imperial College of London


Unconventional Manufacturing

The gadgets are fabricated in-house within the faculty’s Imperial Plasma Propulsion Laboratory with a MEMs course of they developed. They use reactive ion etching with a refractory metallic to create the form of the machine. The subsequent step sputter-deposits an iridium layer which each acts as an ignition catalyst and creates an oxidation protecting layer to the machine partitions.

The thruster would work equally properly with a tanked gaseous hydrogen and oxygen provide system. Nevertheless, that may take up extra space, be weak to leaks and explosions and would require extra regulation {hardware}. By using ice, significantly fewer parts are required and the gasoline/oxidized mixture is secure and protected.

It may appear inefficient to separate the 2 parts, solely to recombine them an instantaneous later. Nevertheless, with solar energy used for the electrolysis, no onboard assets are required and minimal {hardware} parts are wanted to assist the entire system.

When each gasses are combined within the combustion chamber, the indium catalyst begins the burn which produces thrust. Whereas the online energy used is greater than gained by combustion, extra energy is produced than could be with different electrical and ion primarily based thruster techniques.

The school lab has developed two micro thrusters, The ICE-200 with closing design thrust of 1 – 2 N (Newtons) and the ICE-Dice, talked about above, with 5 mN design thrust.