Nancy N. Rue 
Sophie Under Pressure [EPUB ebook] 

Sophie and her friends are all part of an elite expedition. In order to save the world (and their science grades) they are called upon to build an elaborate space station in Fiona’s backyard, and are soon lost in the world of telescopes and zero-gravity. Sophie, however, realizes building that space station is only a small solution to a much bigger dilemma when her friends and fellow astronauts begin to fight. Will she be able to complete her mission and save the Flakes’ friendship before her whole world falls apart?