Researchers, led by a former NASA chief technologist, hope to launch a satellite that runs on water as a fuel source. The Cornell University group and Mason Peck want their device to be the first CubeSats (these are small satellites the size of a shoebox) to orbit the Moon while demonstrating the potential of water as a fuel source for a spacecraft. This safe and stable substance is quite common even in space and could find even more widespread use on Earth, since we are looking for an alternative to fossil fuels.
Until we develop a warp drive or some other futuristic propulsion system, our space travel is likely to rely heavily on rockets using the same fuel that is common today. They work by burning gas in the back of the apparatus and due to this, thanks to the laws of physics, they are pushed forward. Such propulsion systems for satellites must be lightweight and carry a lot of energy in a small space (have a high energy density) in order to continuously maintain the apparatus for many years or even decades in orbit.
The first concern is safety. The packaging of energy in small volume and mass in the form of fuel means that even the slightest problem will lead to disastrous consequences like what we saw with the recent explosion of SpaceX's rocket. Putting satellites into orbit with any form of unstable fuel on board could spell disaster for expensive equipment, and maybe even worse for human life.
Water can help us get around this problem, as it is essentially a carrier of energy, not fuel. The Cornell University group has no plans to use water as fuel, but rather use electricity from solar panels to split water into hydrogen and oxygen and use them as fuel. These two gases combine and become an explosive mixture, allowing to realize the energy expended in splitting water. The combustion of these gases can be used to move the satellite forward, accelerate it, or change its position in orbit, depending on the destination.
Solar cells are highly reliable and have no moving parts, making them ideal for microgravity and extreme space environments to generate current from sunlight. Traditionally, this energy is stored in batteries, but Cornell scientists want to use it to break down water on board.
The proposed process - known as electrolysis - involves passing current through water, usually containing some soluble electrolyte. The current breaks water into oxygen and hydrogen, which are released separately at two electrodes - at the anode and cathode. On Earth, gravity then separates these gases and they can be used. But in zero gravity, the satellite will need centrifugal forces from rotation to separate gases from solution.
Electrolysis has already been used in space in the past to provide oxygen to manned space missions and not take up high-pressure oxygen tanks, for example, on the International Space Station. But instead of sending water into space as a cargo on a rocket, we could just mine it one day on the moon or on asteroids. If this new approach to using hydrogen and oxygen for satellite fuel proves to be successful, we could have a ready-made source of it in space. This approach could be applied to the power supply of the spacecraft of the future.
As is often the case, developments in space technology give rise to ideas that can be applied on Earth, especially in solving significant energy problems. Electricity is really difficult to store, and as the demand for electricity increases, we need breakthroughs. Wind and solar farms are not the most efficient forms of renewable energy, not because of problems with energy production, but because we often cannot do anything useful with this energy. Electricity grids fail during periods of high generation and low energy demand.
Promotional video:
Perhaps it will help us to use excess electricity to split water into hydrogen and oxygen. Then you can make stocks of hydrogen, and, if necessary, combine it with oxygen from the atmosphere.
ILYA KHEL