NASA Memorial: 17 prior, not 10 prior?

Factual Questions
1

Several times, the media has made mention of a memorial on the grounds of the Kennedy Space Center paying homage to 17 lost astronauts. At first, I thought the media meant: 3 Apollo + 7 Challenger + 7 Columbia = 17 astronauts.

However, it was repeated again, this time saying NASA would be adding 7 more names to the 17 names for a total of 24 names. So, who are the missing 7? Test pilots for NASA? Or, could it be out of respect to lost Cosmonauts?

Anyone know the scoop on this? - Jinx

2

It includes those members of the astronaut corps that died in training accidents.

3

For example, astronauts Charles Bassett and Elliot See died when their T-38 crashed in St. Louis in 1966.

http://www.whosaliveandwhosdead.com/oeastro.htm

4

Michael Adams, Charles Bassett, Sonny Carter, Theodore Freeman, Robert Lawrence Jr., Elliot See Jr. and Clifton Williams Jr. died in aircraft crashes.