@misc{indiciae35029e6874bb,
  title = {Europa exploration: challenges and solutions},
  author = {Johnson, Torrence V. and Clark, Karla and Greeley, Ron and Pappalardo, Robert},
  year = {2002},
  url = {https://ntrs.nasa.gov/citations/20060044207},
  note = {Source identifier: 20060044207}
}