half life question

hey guys, obviously i'm a moron cuz i just started playing half life (the original)!! neway, i'm stuck on the planet XEN level after teleporting... I cant figure out how to jump from one floating rock island thing to the other!! supposedly with the new orange suit I picked up i should be able to jump much further but it doesnt seem like it... I run, hit CTRL + SPACE to get maximum distance but i come up short EVERYTIME!! please help me... thank you