time. Estimates ranged from a few to hundreds of atmospheres). Finally, it was subjected to accelerations of up to 450 g in a centrifuge. The centrifuge test caused cracking of electronic components and cable brackets, which were replaced shortly before launch. The timing for the launch was rather tight, so as not to miss the launch window — the days of the year when the path to the destination planet from Earth is energetically least demanding. The capsule could float in case of a water landing. Considering the possibility of such a landing, its designers made the lock of the capsule using sugar; it was meant to dissolve in liquid water, releasing the transmitter antennas. The capsule contained a newly developed vibration-damping system, and its parachute could resist temperatures up to . The capsule contained an altimeter, thermal control, a parachute and equipment for making atmospheric measurements. The latter included a thermometer, barometer, hydrometer, altimeter and a set of gas analysis instruments. The data were sent by two transmitters at a frequency of 922 MHz and a rate of 1 bit/s; the measurements were sent every 48 seconds. The transmitters were activated by the parachute deployment as soon as the outside pressure reached , which was thought to occur at the altitude about above the surface of the planet. The signals were received by several stations, including the Jodrell Bank Observatory. The capsule was equipped with a rechargeable battery with a capacity sufficient for 100 minutes of powering the measurement and transmitter systems. To avoid becoming discharged during the flight to Venus, the battery was kept charged using the solar panels of the carrier spacecraft. Before the launch, the entire Venera 4 station was sterilized to prevent possible biological contamination of Venus. Mission Two nominally identical 4V-1 probes were launched in June 1967. The first probe, Venera 4, was launched on 12 June by a Molniya-M carrier rocket flying from the Baikonur Cosmodrome. A course correction was performed on 29 July when it was away from Earth; otherwise, the probe would have missed Venus. Although two such corrections had been planned, the first one was accurate enough and therefore the second correction was canceled. On 18 October 1967, the spacecraft entered the Venusian atmosphere with an estimated landing place near . The second probe, Kosmos 167, was launched on 17 June but failed to depart low Earth orbit. During entry