At this posting there are less than 60 days left to get your name and a message added to the MAVEN (Mars Atmosphere and Volatile Evolution) mission. According to the MAVEN web site everybody on the planet is welcome to participate. Your name will be written to a DVD and sent into Mars orbit on the spacecraft.
The Mars Atmosphere and Volatile Evolution Mission (MAVEN), set to launch this year, will explore the planet’s upper atmosphere, ionosphere and interactions with the sun and solar wind. Scientists will use MAVEN data to determine the role that loss of volatile compounds, such as CO2, N2, and H2O, from the Mars atmosphere to space has played over time, giving insight into the history of Mars atmosphere and climate, liquid water, and planetary habitability.