NASA believes that its giant launcher, SLS (Space Launch System) could take off from 23 August. For this inaugural Artemis I flight, it will send into orbit around the Moon an uncrewed Orion capsule with a European service module.
After years of delay and cost overruns, the American agency is finally preparing to inaugurate the Space Launch System or SLS, a launcher designed with the Moon in its sights, even if other missions remain possible.
NASA Is Capable
Last April, NASA had tried to carry out a countdown test. Due to multiple problems, the SLS returned to the VAB hangar at the Kennedy Space Center in Florida, without the teams being able to fill the hydrogen and oxygen tanks completely (respectively 2 million litres at -253°C and 741,941 litres at -183°C!).
The 98 m tall launcher returned to its launch pad LC-39B (constructed for Apollo and used for the shuttles) in June. This time, filling was complete, even if a hydrogen leak put a stop to the countdown rehearsal at H-29 seconds when H-10 seconds was the target. The American agency believes that the difference is not significant and gave the green light for the next stage … the take-off!
The NASA video above was put online on 30 June. Its title Artemis I: We Are Capable underlines the confidence of the agency which sees in Artemis I the most challenging launch of its programme to return to and on the Moon.
At the End of August, Beginning of September … or Later
Artemis I is an uncrewed mission. The SLS will send an Orion capsule to the Moon. It will orbit our natural satellite for several days before coming back to splash down on Earth.
It is, therefore a rehearsal for Artemis II which will follow the same scenario, this time with four astronauts aboard (planned for 2024). The European Space Agency (ESA) is a leading partner in the Artemis programme and, furthermore, provides NASA with the service module ESM (European Service Module) for the Orion capsule. Built by Airbus Defence and Space with Thales Alenia Space as a subcontractor, this module houses the propulsion and supplies electricity as well as oxygen. In other words, Orion cannot orbit our celestial neighbour without ESA.
At the moment, the SLS has returned to VAB to be prepared for its inaugural flight. The first possible launch window, if there are no technical problems, starts on 23 August for the following few days (local time in Florida for take-off with its Metropolitan France equivalent).
The precise launch window for a given day, the period of time during which the SLS can take off from the indicated time. Depending on the start date, the mission will be called a short one (26 to 28 days) or a long one (38 to 42 days). This means that the Orion capsule will return to Earth after this period.
If the SLS is not ready for these dates from the end of August to early September, the position of the Moon in its orbit will require awaiting another window from 20 September to 4 October (except for 29/09). Subsequently, every month has about ten days during which the SLS could take off and send the Orion-ESM duo around our natural satellite.