Electric fields provide the largest part of wave-particle interactions in the important ion cyclotron frequency range at 1 AU. Hence their study is essential for understanding the turbulent solar wind. In particular, this study would be an important objective for spacecraft closer to the sun. At present, the best measurements of solar wind electric fields have been provided by the EFW experiment on Cluster [1,2]. The Cluster spacecraft are spinning. It would seem that a 3-axis oriented satellite would provide better measurements, since photoelectric effects on spinning satellites are often in the essential frequency range, and often much larger. That is why electric fields have rarely been measured. On the other hand, the 3-axis stabilized STEREO spacecraft are apparently unable to measure electric fields in this frequency range. Reasons why this is so will be discussed, as will the implications for further measurements.