The quasistatic electric field experiment on the ISEE-1 satellite uses spherical double probes to measure the electric field. The potential of each probe relative to the plasma potential can be controlled with a bias current, which compensates for the loss of photoelectrons from the probe. Thus, keeping a probe at plasma potential, the satellite potential is measured with reference to the probe. The dependence of the satellite potential on the ambient plasma electron flux is discussed. It is shown theoretically and found experimentally that the satellite potential is proportional to log(n//eT//e** one-half ). Examples are given of how the satellite potential varies in different regions of space penetrated by ISEE.