NASA prepares the launch of Artemis 2: four astronauts will fly around the Moon for ten days aboard the Orion capsule. But the mission remains risky and the launch window is very narrow.
After several postponements the new manned lunar mission of the program Artemis 2 it could be launched on April 1st. This was announced NASA on Thursday 12 March after the last check on the state of flight readiness. US space agency officials said they aimed to relocate the rocket SLS (Space Launch System) and the spaceship Orion to launch pad 39B by March 19 ahead of a launch attempt scheduled for the first day of next month, provided remaining work is completed.
The postponement and the new launch window
The launch was initially scheduled for earlier this month, but a helium leak from the fuel system forced technicians to return the giant rocket to the assembly hangar. The work was carried out in record time and now everything seems ready to take advantage of the new launch window – dictated by the relative position of the Moon with respect to the Earth – which will occur from 1st to 6th April. There is a lot of anticipation especially for one thing: it would be the first manned mission on the Moon after theApollo 17 from 1972. In a post on social media Xthe US Space Agency’s Office of Communications released this note: “We are targeting March 19 to move the rocket to the NASA Kennedy launch pad for a launch attempt on April 1, provided work on the pad is completed.”
The risks of the mission according to NASA
When asked how risky this mission actually is, the NASA he preferred not to make any statements but to remind us that it is necessary to proceed with every precaution, without taking risks, also because this undertaking with this rocket has never been attempted before and therefore we have to deal with a scarcity of available information.” In fact, from the NASA center in Houston they recall that “all manned space missions are risky and Artemis 2 will be only the second flight of the Artemis program and the first to carry astronauts, so there is not yet sufficient data to correctly quantify the risks involved. According to NASA there are six potential launch dates in April (1, 3-6 and 30); each window lasts 120 minutes on all these dates. This means there are only a few opportunities in a month and some of these may be canceled due to bad weather or the need to replenish materials such as rocket fuel.
Orion’s journey around the Moon
But if everything goes smoothly, Artemis 2 will take off from Kennedy Space CenterFlorida, with the Canadian astronaut on board Jeremy Hansen and the Americans Reid Wiseman, Victor Glover and Christina Koch on a journey of about 10 days around the Moon aboard the capsule Orionwhich however will not head directly to the Moon: the SLS rocket will first take Orion into high Earth orbit, where the crew and teams on the ground will carry out a series of checks to ensure that the capsule is ready for its journey. Therefore, the launch day and time must allow the rocket to position the Orion in that orbit to be correctly aligned with the Earth and the Moon at the time of the translunar maneuver which, as the name suggests, will put the spacecraft on course for our satellite. Orion will fly over the Moon following a “free return” trajectory using lunar gravity to return to Earth, without the need for any other significant engine firings.
Fuel, sunlight and returning to Earth
And fuel is precisely one of the variables to be carefully managed: the energy needs of Orion further limits the mission launch window. The trajectory must ensure that Orion does not remain in the dark for more than 90 consecutive minutes, so that the solar panels can receive and convert sunlight into electricity. So mission planners rule out launch dates that could lead to Orion entering prolonged eclipses during flight. In the last phase of the mission, during its high-speed re-entry from the Moon, the thermal protection system of Orionfive meters wide, will have to withstand very high temperatures to ensure the safety of crew members. According to probabilistic studies, there is an overall risk of failure of 1 in 30 during a crewed Artemis mission to the lunar surface and 1 in 40 during the operational phase on the Moon. A high risk compared to that of the missions of SpaceX towards the Space Stationof 1 in 200, but much smaller than that of the Apollo missions of the 1960s, of 1 in 10.
