<DOC>
<DOCNO>
143
</DOCNO>
<TITLE>
interplanetary orbits .
</TITLE>
<AUTHOR>
vertregt,m.
</AUTHOR>
<BIBLIO>
j.brit.inter.s. 16, 1958, 326.
</BIBLIO>
<TEXT>
  the basic equations under simplified
conditions for interplanetary flight are derived .
for a voyage from planet to planet an
unlimited number of orbits is possible .  in
order to give a clear survey of these possible
orbits a diagram is developed from which the
approximate energy-requirement, the duration,
and other particulars of a voyage can be
easily found .
</TEXT>
</DOC>
