S035S is a special callsign celebrating the 35th anniversary of amateur radio in the R.A.S.D. (Western Sahara). More details including operating period to follow. It appears LoTW will not be used. 

*Picture below is of S0RASD team from 1987. You can find out more about that activity here

SØRASD 1987 Team – OH2BH Marti – S01AH Man, S01A Naama and EA2JG Arseli.