About Tom Swift, Jr. - Boys’ series of 33 well-written, imaginative science adventure books published from 1954 through 1971. These followed the earlier 1910-41 40-volume Tom Swift series, but are NOT revisions/condensations of the earlier series. They are entirely new plots with new characters, but feature some of the family and friends of the earlier series. So the admired and groundbreaking new inventions of the Jr. series are from a much later era, inspired by the space flight advances then in the works, and in the news of the day. #21 in the series. Grosset and Dunlap. Copyright 1963. Rear cover lists to Captive Planetoid (1967), and therefore the print run is estimated at about 1967. Very nice, sturdy picture cover. Black/white space lab endpapers. No writing/markings, no tracking, minimal edgewear and corner bumping. Strong hinges. In this one, Tom uses his latest invention, a magnetic deflector, to dispel a toxic radiation defense field surrounding the asteroid Nestra, to rescue men and supplies held there by the enemy. TS21K