WASHINGTON: Scientists have built a new sort of micro satellite known as CubeSat, which can be manoeuvred in orbit with the help of teeny tiny bursts of water vapour. The use of micro satellites and nano satellites, which are much smaller than traditional spacecraft and can be produced at a lower cost, has become more common.
It is possible that thousands of these small satellites may be sent into space to carry out a wide range of missions, including as providing high-resolution imagery and internet services, responding to natural disasters, monitoring the environment, and performing military surveillance. According to Alina Alexeenko, a professor at Purdue University in the United States, “They provide a chance for new missions, such as constellation flying and exploration that their bigger counterparts cannot affordably perform.”
CubeSats, on the other hand, need micro-propulsion devices in order to reach their full potential. These devices must be able to produce accurate low-thrust “impulse bits” for use in scientific, commercial, and military space applications. According to the experts, the new micro propulsion system utilises water that has been filtered to an extremely high standard.
The novel propulsion device, which is known as a Film-Evaporation MEMS Tunable Array (FEMTA) thruster, makes use of capillaries that are sufficiently tiny to exploit the microscopic characteristics of water. Even though the capillaries only have a width of around 10 micrometres, the surface tension of the fluid prevents it from leaking out even when the surrounding environment is completely vacuum.
By turning on the little heaters that are positioned close to the terminals of the capillaries, water vapour may be produced, which in turn generates propulsion. By using this method, the capillaries transform into valves that are responsive to the activation of the heaters. The mechanism is comparable to that of an inkjet printer, which relies on heaters to propel droplets of ink into the printing head. According to Alexeenko, “it is believed that there is ample water on the Martian moon Phobos, which would make it possibly a very large gas station in space.”
“Water is also a highly clean propellant, lowering the possibility of contamination of sensitive equipment by the backflow from thruster plumes,” he added. “This is another advantage of using water as a propellant instead of other options.” CubeSats are assembled from many components, each of which has a volume of 10 cubic centimetres. During the course of the study, a prototype of a one-unit CubeSat was constructed with four FEMTA thrusters, each of which was loaded with about a teaspoon of water and tested in a vacuum. The prototype, which weighs 2.8 kilogrammes, was equipped with electronics and a sensor for an inertial measurement unit to evaluate the functioning of the thruster system. This system spins the satellite by emitting brief bursts of water vapour.
The typical size of a satellite is comparable to that of a school bus, and they may weigh thousands of pounds and cost anywhere from tens of millions to hundreds of millions of dollars.
CubeSats may be assembled using off-the-shelf parts that are very inexpensive, in contrast to the specialised electronics that are required for traditional satellites in order for them to function well in the harsh environment of space. It is possible to deploy satellite constellations consisting of many individual spacecraft that are disposable and have low launch costs. This would reduce the effect of losing individual satellites.
Published at : 10 Aug 2022 10:52 AM (IST)