There is nothing like a 'official download' of the blockchain^{(and it is a bad idea)}, but if you already have one node, you could copy its blocks directory to the other node's SSD and then start it up. Bitcoin Core detects that the directory changed and starts indexing it without redownloading everything. Keep in mind that on many such small board computers you spend more time verifying (computationally intensive) than downloading, as evidenced by a usually much slower IBD speed than what your internet connection offers.