Quoting from the Wikipedia entry on Gordon Cooper:

"On April 29, 2007 Cooper's ashes (along with those of Star Trek actor James Doohan and 206 others) were launched from New Mexico on a sub-orbital memorial flight by a privately owned UP Aerospace SpaceLoft XL sounding rocket. Although the capsule carrying the ashes fell back towards Earth as planned, it was lost in mountainous landscape. The search was thwarted by bad weather but after a few weeks the capsule was found and the ashes it carried were returned to the families.[6][7]

"The ashes were then launched on the Explorers orbital mission (August 3, 2008) but were lost when the Falcon 1 rocket failed two minutes into the flight.[8]"

Link here:

http://en.wikipedia.org/wiki/Gordon_Cooper

Scientific American article on the second flight loss:

http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=solar-sail-and-ashes-of-star-treks-2008-08-04