Edmond Hamilton 
Captain Future #3: Captain Future’s Challenge [EPUB ebook] 

Striking terror on four worlds, a mysterious raider throttles interplanetary commerce—and Earth summons Curtis Newton, the Wizard of Science, and his trio of Futuremen to combat this sinister menace….
The Captain Future saga follows the super-science pulp hero Curt Newton, along with his companions, The Futuremen: Grag the giant robot, Otho the android, and Simon Wright the living brain in a box. Together, they travel the solar system in series of classic pulp adventures, many of which written by the author of The Legion of Super-Heroes, Edmond Hamilton.