US space agency Nasa will put its latest <a href="https://www.thenationalnews.com/uae/2021/11/22/worlds-most-powerful-rocket-will-soon-take-astronauts-to-the-moon/" target="_blank">Moon rocket</a> to the test this week before it blasts off on an unmanned flight in May, ushering in the next era of lunar exploration. On Friday, the Space Launch System rocket, along with the <a href="https://www.thenationalnews.com/uae/science/artemis-missions-nasa-to-conduct-ground-test-of-moon-rocket-on-thursday-1.1186735" target="_blank">Orion</a> spacecraft, will be at the launch site at Kennedy Space Centre in Florida for a process referred to as a wet dress rehearsal. The term describes a practice run during which liquid propellants such as oxygen or hydrogen are loaded. In this case, the 101-metre Space Launch System – the most powerful rocket Nasa has built so far – will take on more than three million litres of super-cold propellants. Flight engineers will also run through a launch countdown that will end before ignition time. The rehearsal is to ensure the 2,608-tonne rocket is ready for its test flight scheduled for May. It is the first of many missions planned for the Artemis programme, which is intended to establish a human presence on the Moon. “Everybody at the Kennedy Space Centre is really excited about where we're at right now,” said Tom Whitmeyer, associate administrator for exploration systems development at Nasa’s headquarters in Washington. Friday is a milestone moment for the vehicle, he said, and “to be here for a new generation of a super heavy lift exploration class vehicle is going to be a day to remember.” “I think it's a tremendous day for the country, aerospace community and our national partners that will be part of this journey,” Mr Whitmeyer said. The process was delayed from February 12 to allow engineers more time to complete the assembly process. At 1am, UAE time, the rocket will complete a 6.2-kilometre journey to reach the launch pad from the assembly building, weather permitting. Artemis launch director Charlie Blackwell-Thompson said the rehearsal would be postponed if there is a greater than 10 per cent chance of lightning within 20 nautical miles. There are also hail, wind and temperature restrictions. “We do have some potentially inclement weather on Wednesday, but right now the forecast looks really nice for roll-out on Thursday,” she said. Artemis 1 involves a four-to-six-week mission to the Moon, starting with 3,991 tonnes of thrust when the rocket lifts off. Once Orion separates from the rocket and leaves Earth’s orbit, a service module provided by the European Space Agency will help supply propulsion and power to the spacecraft to make its journey to the Moon possible. Orion will spend about six days in the Moon’s orbit to collect data, so mission control can assess its performance. The launch of Artemis 2 is planned for 2024 and includes a crewed mission that will orbit the Moon. Artemis 3, the first <a href="https://www.thenationalnews.com/uae/science/moon-grab-nation-states-and-billionaires-compete-in-new-space-race-1.887602">human lunar mission</a> under the programme, has been delayed until 2025.