Apollo's Outcasts by Allen Steele

 This book reads like a pastiche or homage to several of Heinlein's juvenile works, and a couple of his novels for adult readers, too, such as Between Planets, The Moon is a Harsh Mistress, and Thet Menace from Earth, right off the top of my head. Jamie, Melissa and Jan are the children of a scientific bureaucrat within the international space agency who signed a petition to keep the Helium 3 resources out of the greedy claws of the current Vice President of the United States. When the President dies suddenly, allegedly assassinated by PSU (Chinese) agents, and the VP takes power, he realizes that he is in danger, and that his children can be used as leverage against him, so he sends them off - to the Moon - for safety.

This is a heavily disguised blessing for Jamey, who was born on the Moon, but who has lived his life on earth up to the age of sixteen in a powered mobile (read wheelchair) since his bones and muscles are not strong enough to support him on Earth unassisted. So, though it is emotionally traumatic and all very suspenseful, Jamie really blossoms...or perhaps soars is a better term, when he arrives at the lunar colony of Apollo. Jamey's best friend, Logan, is also along for the ride, as are the two children of another family of scientists, , one of whom is developmentally disabled, which turns out to be a brilliant gadget whereby Steele can do some expository work, explaining simple things about the Moon and its colony. At the last minute, before they board their shuttle to the Moon, Jamey's older sister, Jan, is replaced by Hannah "Smith", who arrives suddenly in a limousine, accompanied by Men in Black. It's all very mysterious to Jamie, but not so much to the rest of us.

After that, it's all mostly a coming of age novel, set in lunar orbit, complete with bullies, teenage angst and know-it-all atttitude, and a tale of rebellion against tyranny where boy gets girl in the end.
A good, innocent read. Steele has written so many great books over the years, and this one adds to his legacy.