Science news this week: NASA announces nuclear rocket, space reproduction proves difficult, and why weed gives people the munchies - Live Science

Science news this week: NASA announces nuclear rocket, space reproduction proves difficult, and why weed gives people the munchies  Live ScienceHuman sperm get lost in space, pioneering study finds  Scientific AmericanSimulated microgravity alters sperm navigation, fertilization and embryo development in mammals  NatureSperm Get Lost in Space and Scientists Finally Know Why  SciTechDailySperm get lost in space, Australian research into microgravity impacts suggests  The Guardian