Resolution Criteria
The earliest launch window for Artemis II opens on February 5–11, 2026 with the mission planned to launch no earlier than February 6, 2026. This market resolves to the calendar date on which Artemis II actually launches. Resolution will be determined by official NASA announcements and confirmed by NASA's official mission status page at https://www.nasa.gov/mission/artemis-ii/. A dress rehearsal of the countdown is planned for early February, and NASA Administrator Jared Isaacman has stated that an actual launch date will only be confirmed after that is complete.
Background
The 10-day mission will carry NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, on a free-return trajectory around the Moon and back to Earth. On January 18, 2026, the SLS rocket, Orion capsule, and launch tower were rolled out from the Vehicle Assembly Building to Launch Complex 39B. A wet dress rehearsal is targeted for no later than Feb. 2, during which the team will load the rocket with cryogenic propellants, run through the countdown, and practice safely draining the propellants from the rocket.
Considerations
Because Artemis II is the first crewed flight test of the Artemis campaign, running into a few issues that could cause delays is probable. The uncrewed Artemis I mission, for example, was delayed three times – twice for technical issues and another time due to bad weather – before launching in November 2022.
1,000Referencing ECMWF (9km 1-hr for the temperature constraints) and the 0.25 deg public one for the ensembles to get spreads for various variables) the most serious constraint for the first possible upcoming wet dress rehearsal is the 24h average temperature:
(Quoting https://www.nasa.gov/artemis-ii-weather-criteria/):
"Do not initiate tanking if the 24-hour average temperature at both 132.5 feet and 257.5 feet is less than 41.4 degrees Fahrenheit."
By my best guess for the first wet dress rehearsal (WDR) the tanking should start around 2026-02-02 17:00:00 (possibly being delayed up to 1-3 hours I'd guess) but the 24 hour average temps should be below, violating this constraint (the spread for the ensemble is fairly small when its not far out (95% CI of ~ +- 1 C) and so I have fairly good confidence given the 2m IFS temps temps are for 17Z to 19Z (for the rolling 24 hour average prior 4C or below) (the temps at the heights mentioned will be slightly colder)
The next 2 possible WDRs don't seem to have a temperature constraint issue. None of the WDRs or launches seem to have a wind issue near the surface. Unfortunately so far out (~ 10-11 days) is too far to predict the jetstream location, and that might be an issue with respect to vertical wind shear at the higher levels. The det. model indicates ~100 kt VWS (200-850mb, gradual mostly in the same direction as you would expect) on Feb 10, and ~50 kt on the Feb. 11 window. The ensemble also shows a similar pattern with Feb. 11 being slightly more favorable. However this can only be said with low confidence so far out. That it seems like it will most llkely be gradual doesn't seem to indicate Feb. 10 is ruled out despite it being fairly high... (it depends within a specific layer I assume which won't be known until a short time beforehand).
With the first launch window excluded due to the first WDR being likely ruled out as mentioned above, that leaves the other two (10th and 11th). The temps for the launches should likely have no problems. Same for low-level winds.
Clouds are always going to be an unknown but the pattern in the ensembles suggest the 10th is slightly more favorable than the 11th.
Per the det. models lightning does not seem to be an issue as CAPE is essentially 0 for the entire period of interest so this should satisfy the 20% lightning constraint (Same is confirmed with ECMWF's lightning density product for its ensembles). So weather I'd roughly estimate is >95% favorable for the remaining WDRs, and for the launches >90% with low confidence (VWS being the limiting factor as a known-unknown). Overall subjectively I expect the weather then having >85% of being favorable for the other two launch windows.
With weather discussed, that only leaves priors for launches. As I am less interested in this, I leave the estimation of the probability for some non-weather related issue to impede the WDR / launches to chatgpt (which gives it conditionally 55-75% of it launching). Conditioning on this with my rough subjective estimate of 85% of favorable weather leaves the chances of a launch on one of the remaining two days to 0.65*0.85 ~= 55%. As mentioned the wind shear is worse on Feb. 10 then 11, but the 11th may be a bit more cloudy perhaps. The VWS seems a more serious issue so I will favor the 11th slightly.
I note that NASA has now provided a detailed timeline for their first WDR…
https://www.nasa.gov/blogs/missions/2026/01/31/countdown-begins-for-artemis-ii-wet-dress-rehearsal/
The go/no go for tanking is around 14Z (a few hours ahead of my estimate but should actually make it more difficult to the go ahead)… I’m a bit surprised they went ahead with this given the schedule.. Maybe they have a different forecast but this still seems unlikely. I assumed they would postpone the wet dress rehearsal a day so they could do the tanking…. I don’t know what happens if they can’t as far as another rehearsal (but another one seems unlikely). Given thus the tightness in the schedule I’m going increase the bet in Other assuming that they won’t be able to do the full WDR.