I am currently working with a US government system for downloading public scientific data. You select some data you want to download and add it to a shopping cart. Check out, and select 'create database'. This generates your own copy of an Oracle database, with your own credentials and hostname and db name. Connect to that and construct a query against a table that has some metadata about studies you're interested in. Using the identifiers from that table, join with a LIKE against another table for s3:// URLs. (There are no primary keys and the other table's column is not exactly the same; you need to use a LIKE. This is all documented.) Those s3 URLs point to a CSV which contains another identifier which you use to download manifests which contains links to a web page created on-the-fly which contains to the s3 files to download. By the time you've done all this, your access has likely expired and you must start over from scratch.