This has been discussed extensively before, see Would a “Speculation” tag be useful?, and the linked questions and discussions.
The preferred tag, in the cases where the question is on topic is design-alternative. It was selected over hypothetical-invention and hypothetical-scenario. hypothetical is even more ambiguous than the two.
We don't want this tag.
The first four use structure in a different way than the last. For the first four, I think the design tag would work well, or the more specific engine-design.
For the last one, it is talking about structuring plans for an agency. I think the planning tag would be better there.
I'm not sure that this is really necessary since "Lunar Module" is a pretty well understood name here, and any future spacecraft used for that purpose will probably have different names. If it does become an issue, we can always make a change at that point, but I don't think there's a need to do anything preemptively.
Before you create that new tag, stop and consider the following:
Note: The example questions used here are intentionally basic and should not be taken as a guideline for what is appropriate to ask on the site.
1. Is this a useful way to categorize the question?
For example, if your question is "Why do rockets sometimes explode?", then rockets and rocket-...
I don't see evidence at that link that Crew Dragon is the only official name of Dragon 2, and I still see other recent SpaceX pages using "Dragon 2". The way the community had been using the two different tags was that crew-dragon was for questions regarding the spacecraft's intended use as a human spaceflight craft, whereas dragon-v2 was inclusive of its ...
To me solar-power and the proposed tag photovoltaic-cell serve different purposes. solar-power is about energy source design, specifically designs made to draw power from the sun. photovoltaic-cell is about the use of a specific technology, regardless of the context of its use. I think solar-power should remain and not be made a synonym of anything. Likewise,...
IMO - the "questionable" one is fine, but the other two should be untagged. I don't think a general "identify-this" tag is useful. That's kind of the point of most questions: to explain the phenomenon the person asked about.
Aside from the fact that you pointed out that not all separations may be considered related to staging, there is another implicit difference I see between these two terms--may not always be there but is definitely sometimes implied. "Stage separation" describes a process, whereas "separation" is a single event.
That said, I'm not clear on how we should ...
The flipside here is called burnination, where the community removes tags. It's worth reading what the overall methodology is, but you should pay attention that tags must be clear
We recently reversed a tag synonym because [neo] was potentially vague. I've seen that happen a lot, where a tag goes with an acronym or simple name, and thus you wind up with ...
Near-Earth asteroids are a perfect subset of Near-Earth objects, which means that the tag is distinct, though overlapping. Since near-earth-asteroid has more questions than neo, I think it makes sense to maintain as a separate tag, but it could use a tag excerpt as you've pointed out.
From what I can see, the current usage of the tag is:
General orbital mechanics questions.
Systems in Earth orbit.
Launches specifically dealing with reaching orbit, like sub-orbital vs. orbital comparisons.
From what I can see, only 1) is strictly unnecessary. (skimming the 18 questions, I think that's the case for 8-10 of them)
It's a nice and simple ...
In my opinion, these have some clear differences. The main one is that the CR3BP is much "nicer" than a more general three body problem. The restrictions made makes analytical solutions possible, gives certain constant parameters, etc.
Assuming CR3BP or not has major implications for how you would attack a problem.
At the very least, some re-tagging of ...
Based on the the other answer I've done the following:
I've modified the tag definitions:
Related to the fabrication of products to be used in spaceflight, or the techniques and logistics of production of spaceflight-related items.
Related to the manufacturing of products in reduced gravity ...
I generally think of biology as the deliberate study of living things. It's a scientific field. life refers more to the incidental presence of living things, such as potential extra-terrestrial organisms, or the contamination from one world to another.
I don't think too strongly on the issue, and I could be convinced of a better distinction.
life should ...