This spacecraft was the second in the series of micrometeoroid satellites orbited by NASA. Its purpose was to obtain data on the near-earth meteoroid environment, thus providing an accurate estimate of the probability of penetration in spacecraft structures by meteoroids and allowing a more confident definition of the relationship between penetration flux and material thickness to be derived.
The spacecraft operated satisfactorily during its 7-month life (December 16, 1962, to July 1963), and all mission objectives were accomplished.