Dean, ZD8DC is currently active from Ascension Island on FO-29 and possibly also AO-51 and SO-50.
So far he has been worked in South Africa on FO-29 by ZS1LS and ZS6WB. In both cases the contact has been on a weekend morning ascending pass when he was heard calling CQ around 435.843 MHz SSB.
His activity will probably be mostly on weekends as he works during the week but he could have some good common windows on FO-29 into Africa, South America and Western Europe.
If you are in these areas watch for him especially on 23-29-30 August. He will complete his work assignment on Ascension and return to the U.S. on 02 September.