And not just a vinyl record; a record player, too. After all, our future alien overlords will need a turntable if they're going to learn how to oppress us efficiently.
Actually, the plan is to send up a piece of vinyl and the record player in a balloon with a mechanism that will allow the needle to drop on the record amidst all kinds of upper-atmosphere turbulence. There are still plenty of technical details to work out.
But what vinyl will he send? Jack has always been quite the space cowboy as evidenced by his 2009 Third Man release, "A Glorious Dawn" which features lyrics by Stephen Hawking and spoken word from the late Carl Sagan. Jack is very proud of that record and wants that to be the first vinyl in space.
Note to the distinction of Jack wishing to place the first vinyl record in space. The very first records are already out there: the famous gold discs attached to the Voyageur spacecrafts.