The phrase "attainable until" is correct and usable in written English.
It can be used to indicate a time limit or condition under which something can be achieved or reached.
Example: "The project goals are attainable until the end of the fiscal year, after which they will be reassessed."
Alternatives: "achievable until" or "reachable until".
By that moment, the central computer was already hard at work, tracking every watt in and out, seeking, always, the balance of zero net use over 24 hours — a goal that managers say probably won't be attainable until early next year, when the third wing of the project and a parking complex are completed.
The idea of a folding phone has been a gadget fantasy for many years, but it wasn't attainable until the development of organic light emitting diode (OLED) displays, which are flexible unlike LCD screens.
Although it is a common practice to treat the highest-voltage system as the first approximation, as we did in this study, the correcting terms needed to match the actual flowing currents in the interconnecting transformers will not be attainable until we get the necessary data associated with the lower-voltage systems.
Studies using these kinds of scene viewing paradigms could enable us to infer when adult-like episodic memory may be neurally feasible even if behavioural correlates of episodic memory may not be attainable until linguistic proficiency is achieved.
The requisite methods to produce temperatures low enough to test Einstein's prediction did not become attainable, however, until the 1990s.
I have dreamed about working at the White House for as long as I can remember, but I did not seem like a foreseeably attainable goal until I learned about the internship program.
Stop sitting around and counting the days until your hardships get lifted, or until your dreams become attainable.
But for everybody else, it just makes good moral and economic sense to lower the barrier of entry until attending college is an attainable dream for all of us.
In typical Bills fashion, this team let a very attainable win (and by attainable, I mean Buffalo waited until the last second to let victory slip away) evaporate.
Many prospective candidates spend several elections in unsuccessful seats until they are given the nod for something attainable.
A range of different magnitude inundations can be responsible for depositing a ridge until the ridge approaches a height that is attainable by wave run-ups generated by only very intense TCs.
