What us companies worked in Diego garcia 2002?

DG21 was the major one providing "base services."

"The principal members of DG21 LLC include DS2, a Day & Zimmermann joint venture with Lockheed Martin, First Support Services and W.S. Atkins."--See http://www.dayzim.com/company_information/news/pr_7.18.2006.htm

and

http://dg21llc.net/