validate

Since the Apollo 17 mission, in December 1972, humans have not returned to the Moon. It’s been 53 years since that last manned trip to the satellite, but that could soon change with Artemis II. Of course, it will not be a return to plant a flag and walk on the surface, as Eugene A. Cernan and Harrison H. “Jack” Schmitt did. To set foot on the Moon again (if the program continues as planned) We will still have to wait for Artemis III. What Artemis II proposes is something else: a manned lunar flybya large-scale validation mission and a return to Earth after testing a long list of critical systems. Technology has changed since the 1970s, and that makes this mission something special: not only because of what it represents on a symbolic level, but because of what it implies on a technical level. Artemis II is, in practice, the final exam before the moon landing. And hence the inevitable question: when is it released? As is often the case in the space sector, it is not enough to set a date on the calendar. The window depends on a combination of operational, logistical and meteorological factors, and the room for maneuver is more limited than it seems. Artemis II plays everything in very specific windows The first concept that should be clear is that of the launch window: the time interval during which a specific mission can take off. In the case of Artemis II, NASA has already published a calendar with 16 opportunities distributed between February and April. The first starts on Friday, February 6 at 9:41 p.m. (Eastern time in the United States), which in peninsular Spain is translated as Saturday the 7th at 03:41 in the morning. Artemis II release window schedule for early 2026 And those dates are not set at random. Artemis II requires millimeter orbital choreography: a lunar flyby trajectory, a translunar injection with narrow margins, a free return taking advantage of the satellite’s gravity, and a reentry profile that prioritizes safety and fault tolerance. With such a level of demand, it would be strange to have a broad and flexible calendar. In practice, these missions always move within fairly limited launch opportunities. Artemis II technical calendar: opening of each window, local and UTC times, and duration of each launch opportunity But the orbital schedule is not the only bottleneck. The launch complex itself imposes relevant restrictions. At 39B, the same one from which the Saturn Vthe spherical tanks used to store cryogenic propellant allow a limited number of attempts. Liquid oxygen and liquid hydrogen are loaded into the core stage and upper stage on the same day of launch. And if the takeoff is canceled, you cannot try it again the next day as if nothing had happened: you have to wait. at least 48 hourss to try the process again. Jeremy Hansen, Victor Glover, Reid Wiseman and Christina Hammock Koch, next to the Orion capsule at the Kennedy Space Center (August 8, 2023) If today there is talk of a near launch it is because the mission has already been closing important milestones. The SLS rocket and the Orion capsule are already on the launch pad. They arrived last January 17 after a slow transfer, of about 12 hours, from the Vehicle Assembly Building. From there, the teams began the tasks of connection and integration with the terrestrial facilities, a job that was as inconspicuous as it was decisive so that the next steps could progress smoothly. The big dot marked in red on the calendar is the “Wet Dress Rehearsal (WDR)“, the general fuel loading rehearsal. It is, basically, a complete simulation of the launch day. The team positions itself as if it were the real takeoff and executes the filling procedure with the same level of detail: some 2.7 million liters of cryogenic propellantsbetween liquid oxygen and liquid hydrogen, following the schedule that will be used in the final launch. Of course, the RS-25 engines will not start: the test will stop before that phase. NASA’s Vehicle Assembly Building (VAB) at Kennedy Space Center, Florida NASA has explained in a recent statement who plans to take this test on Saturday, January 31. He also assures that the preparations are going as expected and that they have even managed to advance some tasks. But here experience weighs: the WDR of Artemis I, initially planned for April 2022ran into difficulties and was not completed successfully until June. That delay ended up directly affecting the launch schedule, and is a reminder that, at this point, every detail counts. Therefore, at this point, the scenario still allows for several twists. If any problems appear during WDR, NASA could choose to postpone it, repeat it, or even organize additional rehearsals. There is also a possibility that, after completing the test, it will decide to move the SLS and Orion back to the Vehicle Assembly Building to perform additional work before returning to the ramp. If the WDR is completed successfully, the next step will be a flight readiness review in early February. At that meeting, the management team will evaluate the availability of all systems involved: flight hardware, ground infrastructure, and launch, flight, and recovery equipment. Only after passing that review will an official date be announced. With all this on the table, the first slot on February 6 (already February 7 on the peninsula due to the time difference) appears as the first real great opportunity. QBut just because it exists doesn’t mean it will be used.. Even with everything aligned, NASA could decide to jump directly into one of the next planned gaps in the schedule. The good news is that once the WDR is run, we will have a much clearer map of what can happen. And there is still the factor that has broken perfect plans the most times: time. In a launch of this type, the weather is not a nuance, it is a filter. The rules … Read more