Likewise, President Joe Biden’s administration should aim to target NASA’s efforts at the things [which] only it [NASA] can bring about and for which [things] there is not already a market: high-risk scientific research.
- So President Joe Biden’s administration should use NASA for those things only NASA can do.
- There are two relatives modifying things: only it can bring about is a bare relative clause (in which the relative pronoun has been omitted). This bare relative modifies things and is connected with the second relative (for which there is not already a market) by and. This implies that the second relative modifies the same noun and that the referent of the pronoun which is things.
- Breaking it in shorter sentences can make it clearer but repetitive:
Likewise, President Joe Biden’s administration should aim to target NASA’s efforts at high-risk scientific research. Only NASA can bring about such things/ research. There is not already a market for high-risk scientific research.
I would have said not yet instead of not already though.
- Modern Grammars often analyse the structure of sentences. You this particular question should be asked on ELU Meta.