Amazon persuaded NASA to use S3 rather than the object store NASA invented: Open Stack SWIFT.
Instead of being able to rely on their own work, with minimal cost, now NASA is locked into a multi-year monopoly and will be paying for it for decades. I see this as just another instance of corporations sucking the government tit forever. Maybe this time, it won't be. And Lucy could let Charlie Brown finally kick that football too.
Amazon is in it for the money of course. The question is does it make sense for the country to rope in Amazon when the uses of the product will likely be long term, and no small amounts classified? Those are questions of policy that can be legitimately argued either way, but the final analysis is that government/private sector endeavors almost always seem to sour and fail. Examples are collecting student loans, where the loans are paid to the private contractor, but the principal never makes it back into Government hands. Another are prisons, where treatment of prisoners and their needs significantly decline once government is removed from direct accountability. A third is collecting fees form legal proceedings, where the debtor is invariably put into deeper and deeper holes with fees and fines, and returned to prison. Last, child support payments in states where it's contracted out to private intreats, and the debtor is arrested when the payment processor "forgets" to process the payment sent. (Turns out vindictive spouses are involved.) Predation by the private sector is easy, almost inevitable.
If there are successful partnerships, please chime in and point them out.