Tesla founder Elon Musk has already understood: the energy of the future is gas. In its work to explore and colonize Mars, his company SpaceX has invested in the development of future rocket engines. The new rocket family Raptor are powered by methalox fuel, a mixture of liquid methane gas (gas energy) and liquid oxygen.
Certainly, methalox is a high-octane fuel with high power. But another advantage is that there is the possibility to extract methane on Mars. Future colonisation of our neighbouring planet could lead to the possibility of building gas energy stations on Mars!
The first test of the new Raptor engine with methalox was conducted in Texas in September 2016. A year later, it was announced that a smaller Raptor had been developed, and that several Raptor engines would propel the BFR rocket that is being developed.