@misc{indiciae29acf1e2489d,
  title = {Heliogyro solar sailer Summary report},
  author = {Hedgepeth, J. M. and Mac Neal, R. H. and Schuerch, H. U.},
  year = {1969},
  url = {https://ntrs.nasa.gov/citations/19690019483},
  note = {Source identifier: 19690019483}
}