RS-25 engines powering NASA's SLS (Space Launch System) rocket use liquid oxygen and liquid hydrogen as propellants – the same elements that combine to create water (H2O). For an RS-25 engine test, liquid hydrogen and liquid oxygen are mixed in the engine combustion chamber and ignited, which results in extremely high-temperature exhaust (up to 6,000 degrees F) exiting the nozzle into the flame deflector at a very high rate and pressure. Hundreds of thousands of gallons of water also are flowing

348K views · 4.3K shares | Are you ready to rumble? Our Space Launch System is. SLS, which will be the most powerful rocket ever build, the Orion spacecraft and grounds systems are needed to launch astronauts to destinations far into the solar system. Watch some of the progress being made on our #JourneyToMars. | NASA - National Aeronautics and Space Administration | Facebook

Jo looks at the strengths and weaknesses of Cameron, Miliband and Clegg. On-air, DP is talking to Damian McBride, who used to work for Gordon Brown, and Malcolm Gooderham, who was press secretary to Michael Portillo. | BBC Politics