Heinlein, Robert A.
A young man named Don Harvey leaves his dude ranch high school on Earth to go to his scientist parents on Mars. He visits an old family friend who asks him to deliver a ring to his father, but they are both later arrested by security forces. Harvey is released and given his ring back, after it has been examined; he is told that his friend has died of "heart failure." It is only later that he realizes that all deaths can be described that way. Harvey boards a shuttle to a space station orbiting the Earth. The station doubles as a transshipment terminus and a military base, armed with missiles to keep restive nations in check. On the trip up, he befriends one of his fellow passengers, a Venusian "dragon" named Sir Isaac Newton. Sir Isaac is a renowned physicist who can speak English using a portable device. Harvey gets caught up in the Venusian war of independence when the station is captured by the colonials in a surprise raid. Most of the other travelers are sent back to Earth, while a few decide to join the rebels. Harvey is in a quandary. The spaceship to Mars has been confiscated, but he remains determined to get there, by way of Venus if necessary. Because he was born in space, with one parent from Venus and the other from Earth, he claims Venusian citizenship; more importantly, Sir Isaac vouches for him. He is allowed to tag along, which turns out to be very fortunate for Harvey. The rebels blow up the station to stir up trouble for the Earth government. When the shuttle returns to Earth with its radios disabled, the military assumes it has been booby-trapped and destroys it, killing all aboard