A Fortran rocket from 1987. It reaches nearly 10km in about a minute before falling to earth, simulating the mass, propellant, air resistance, and gravity. The output is a set of data files which were fed to a printer which used pens moving around on an x-y axis, but it was adapted to use gnuplot.
bburns/rocket.f77
An old Fortran program for an aerospace class - simulating a rocket launch with an ODE solver
FORTRAN