During the first telemetry session, it was found that Venera 1 failed to enter the constant solar orientation mode, which led to a shortage of electrical power on board. While unfortunate, this was expected and in such a case the station had to conduct a rough orientation to the Sun and turn off non-vital systems. However, the radio transmitters had not been adequately designed and communication was shortly lost. The signal was regained on 17 February but it was still unable to lock onto the Sun properly and again went into protective mode and turned off the transmitter. Three successful telemetry sessions were conducted, gathering solar-wind and cosmic-ray data near Earth, at the Earth's magnetopause, and on February 19 at a distance of 1,900,000 km (1,200,000 mi). After discovering the solar wind with Luna 2, Venera 1 provided the first verification that this plasma was uniformly present in deep space. Seven days later, the next scheduled telemetry session failed to occur. On May 19, 1961, Venera 1 passed within 100,000 km (62,000 mi) of Venus. With the help of the British radio telescope at Jodrell Bank, some weak signals from Venera 1 may have been detected in June. Soviet engineers believed that Venera 1 failed due to the overheating of a solar-direction sensor.