I will consider 2024 probable when these three things happen, though not necessarily in this order 1. Starship launched to orbit on Super Heavy and booster recovered. Probably in 2021 maybe Q32. Orion launched on SLS for Artemis 1 with no major issues discovered. Probably Q1 20223. Successful in Space fuel transfer between Starships I don't include landing Starship from orbit because even without tanker reuse it's still economical if not paradigm changing.
The way I see it, there are 2 long poles in the SpaceX Lunar Starship HLS. Neither of them having to do with actually landing on the Moon. The actual landing operation will have a lot of commonality with things they've already done and thus have experience with and data from. Namely the hopper flights; SN6, SN5, Starhopper, and to a lesser extent the 'Grasshopper' flights.The two long poles are:1) Starship in orbit refueling and Tanker development/implementation. Getting this in place is vital for the ability to perform the mission as described in their bid and it is the one thing that there is no existing body of operational knowledge available from which to draw. (Rapid turn around, while nice, is not quite as critical, as SpaceX has already proven the ability to construct multiple iterations of its vehicles rapidly and could have several boosters and tankers on standby for the initial attempts.)2) Large scale ECLSS. Here, there is knowledge available from things like the ISS systems, and their hands on experience with Dragon will be useful, but the scale of the pressurized volume is a potential issue, being as it is a single system the size of the ISS.If I had to narrow it down to one single critical path item, it would be the refueling tanker. Luckily, since it is not a item singly dedicated to LSS, it is something that SpaceX can continue to work on even with the contract freeze in place pending GAO decision. (I also personally think that this is the portion of the contract that all along was more heavily weighted toward internal SpaceX funding anyway due to its critical nature for their other plans.) If they can perform a demonstration of this before the end of next year, then I believe the rest can fall into place for 2024, possibly with time to spare.
New Artemis update from NASA's Office of Inspector General: https://oig.nasa.gov/docs/IG-21-018.pdf. It states, that "landing by 2024 is highly unlikely". (End of Quote) Well, let's hope for the best.
SLS is not the pacing item for a Lunar landing. That would be the lander itself.
Refueling ops is unlikely to be the long pole for the crewed landing demo because it's on the critical path for the uncrewed landing demo. It's the stuff they only need for the crewed mission that's most likely to be deferred and become the long pole for Artemis 3. Particularly the requirements that don't have to be met for DearMoon.
Quote from: StarshipSLS on 05/06/2021 06:31 pmNew Artemis update from NASA's Office of Inspector General: https://oig.nasa.gov/docs/IG-21-018.pdf. It states, that "landing by 2024 is highly unlikely". (End of Quote) Well, let's hope for the best.I didn't find this report very convincing. It says that Artemis I will likely be delayed by a few months and they then assume that this delay of a few months will cascade onto Artemis II and III. They then say that since Artemis III is already planned for the end of 2024, the 2024 timeline is therefore unlikely...
Landing by 2024 will not happen.
Quote from: butters on 05/06/2021 06:47 pmRefueling ops is unlikely to be the long pole for the crewed landing demo because it's on the critical path for the uncrewed landing demo. It's the stuff they only need for the crewed mission that's most likely to be deferred and become the long pole for Artemis 3. Particularly the requirements that don't have to be met for DearMoon.The bolded comment makes absolutely no sense as it completely contradicts itself. As the uncrewed demo must come first, any delay there potentially delays the whole program. The only people with any 'in space refueling' practical experience are the Russians and I highly doubt they are willing to share with SpaceX. Of all the things that have to be done, in space refueling is the single critical item with the most development to be done with the least amount of data on how to do it successfully.'Long Pole' means required items that require the most lead time to get done by the scheduled date. You cannot divorce refueling from the LSS work that needs to be done because without it, there is no LSS landing. Saying it is resolved for the demo mission and thus not important for the manned mission is like saying you're sitting down to eat in an hour, but you haven't gone grocery shopping for the ingredients yet.
Quote from: butters on 05/06/2021 06:47 pmRefueling ops is unlikely to be the long pole for the crewed landing demo because it's on the critical path for the uncrewed landing demo. It's the stuff they only need for the crewed mission that's most likely to be deferred and become the long pole for Artemis 3. Particularly the requirements that don't have to be met for DearMoon.The bolded comment makes absolutely no sense as it completely contradicts itself. As the uncrewed demo must come first, any delay there potentially delays the whole program.