Measurements of the solar Lyman alpha and Ca II K from October 1981 to April 1989 show a strong correlation (r=.95) that allows estimation of the Lyman alpha flux at 1 AU from 1975 to December 1989. Our estimated Lyman alpha strength of 3.9¿1011¿.15¿1011 photons/s cm2 on 7 December 1989 is at the same maximum levels seen in Cycle 21. Relative to other UV surrogates (sunspot number, 10.7 cm radio flux, and He I 10830 line strength), Lyman alpha estimates computed from the K line track the SME measurements well from solar maximum, through solar minimum, and into Cycle 22. ¿ American Geophysical Union 1990