Something random I was told about. http://mars.nasa.gov/participate/send-your-name/insight/
The basic gist is
Enter your name.
Nasa engraves your info onto a Microchip.
They put it onto the Insight spacecraft sending it to Mars to do its mission.
(No idea past that though)
Try it if you're interested. "Last Day to Register: September 8, 2015 (11:59 p.m. ET)" It ends in about 3 hours, 40 mins from this post, so it's quite last second. I hope everyone that is interested makes it in time.