Many spacecraft are cruising in space, observing Saturn, the sun, asteroids and comets. The Deep Space Network (DSN) communicates with nearly all spacecraft flying throughout our solar system. While Curiosity is roving on the planet, it is communicating with the Mars Reconnaissance Orbiter via its UHF antenna and to the DSN on Earth by way of its high-gain antenna. The Mars Science Laboratory, while in its cruise stage configuration, communicated through low and medium-gain antennas. The larger the antenna, the stronger the signal and greater the amount of information the antenna can send and receive. These enormous antennas enable humans to reach out to spacecraft millions of miles away. The DSN antennas are extremely large: 34 meters (about 37 yards) and 70 meters (about 76 yards). how fast and how much data the rover can send back.X-band radio waves used by the rover to communicate.how the rover can communicate through Mars-orbiting spacecraft.special signal tones the DSN received during entry, descent, and landing.how the DSN helps engineers navigate the spacecraft during cruise.the size and strength of the DSN Antennas.It will be noted from the below (fig-2) that the total current of each Line is equal to the vector difference between two phase currents in Delta connection flowing through that line. Line Currents (I L) and Phase Currents (I Ph) in Delta Connection Also read : Three Phase Current Values in a 3-Phase System.in Delta connection, the Line Voltage is equal to the Phase Voltage. V RY = V YB = V BR = V L …………… (Line Voltage) Then, we see that V RY leads V YB by 120° and V YB leads V BR by 120°. Likewise, the voltage of Y phase is leading by 120° from the phase voltage of B and its direction is positive from Y towards B. Since the phase sequence is R → Y → B, therefore, the direction of voltage from R phase towards Y phase is positive (+), and the voltage of R phase is leading by 120°from Y phase voltage. Therefore, in Delta Connection, the voltage between (any pair of) two lines is equal to the phase voltage of the phase winding which is connected between two lines. there is one phase winding between two wires).
It is seen in fig 2 that there is only one phase winding between two terminals (i.e. Line Voltages (V L) and Phase Voltages (V Ph) in Delta Connection Three wires are taken out from three junctions and the all outgoing currents from junction assumed to be positive.
In more clear words, all three coils are connected in series to form a close mesh or circuit. Or the starting end of the first coil is connected to the finishing end of the second coil and so on (for all three coils) and it looks like a closed mesh or circuit as shown in fig (1). In Delta (also denoted by Δ) system of interconnection, the starting ends of the three phases or coils are connected to the finishing ends of the coil.
Line Voltages (VL) and Phase Voltages (VPh) in Delta Connection.Voltage, Current and Power Values in Delta Connection (Δ).