In the category "Science" we currently track items of 34 persons. The most popular ones, by number of traded items, are:

Buzz AldrinNeil ArmstrongFelix Baumgartner
Helen SharmanCharlie DukePatrick Moore
Valentina TereshkovaGene CernanJim Lovell
Edgar MitchellDave ScottMike Bannister
Jim IrwinMichael CollinsScott Carpenter
Yuri GagarinJohn GlennJohn Young
Ed MitchellFred Haise 

You can find all people that we're currently tracking items for in the alphabetical index:
A    B    C    D    G    H    I    K    L    M    S    T    W    Y