you can read the novella Drive online: http://www.syfy.com/theexpanse/drive/prequel.php http://www.syfy.com/theexpanse/drive/prequel.php where it appears to be

you can read the novella Drive online: http://www.syfy.com/theexpanse/drive/prequel.php http://www.syfy.com/theexpanse/drive/prequel.php where it appears to be some sort of issue that occurs to his failing fusion drive, so definitely a more efficient fusion drive.