During its lifetime IUE greatly surpassed the expectations of the original science goals set to justify the mission:

• To obtain high-resolution spectra of stars of all spectral types to determine their physical characteristics


• To study gas streams in and around binary star system


• To observe faint stars, galaxies and quasars at low resolution, interpreting these spectra by reference to high-resolution spectra
  
• To observe the spectra of planets and comets


• To make repeated observations of objects with variable spectra


• To study the modification of starlight caused by interstellar dust and gas