Sonia Ostrowski, age 14., of Somerset, Manitoba, Canada, for her question:
How are live pictures transmitted from the moon?
In the early 1960s, it was impossible to transmit live TV across our major oceans. Then orbiting satellites closed this communication gap. And on July 20, 1969 , the astronauts of Apollo 11 set up a capsule TV station on the moon. At 11:11 p.m.,. EST, Commander Neil Armstrong fixed a lens to the camera. Moments later, live TV from the moon reached our living rooms. We saw the leg of the landing module, Eagle, with its plaque that reads: "Here men from the planet Earth first set foot on the Moon . `'
Some people complained that the first lunar TV was in black and white and rather blurry. They did not realize the scientific achievements that made it possible at all. Later, Apollo missions had better equipment and included color. But the relay methods use the same basic route. The live lunar TV is but a small part of NASA'S far flung Office of Tracking and Communications. The big OTDA is the eyes and ears of the entire space program. The Apollo live TV is part of MSFN the Manned Space Flight Network.
And what a network it is. It uses three key tracking stations plus a number of minor ones, microwaves and undersea cables, two million miles of telephone, super superior computers and a capsule two way station on the moon. Thousands of trained personnel around the world stand by to run MSFN during, the Apollo missions.
In the live lunar TV operation, the easiest job is done by a carrier radio, beam that whips across 240,000 miles of space in about one and one third seconds. The tricky jobs are done by a capsule station on the moon and the global network of receiving and relaying centers. A three foot box in the lunar landing module has a small antenna and a camera. It translates both audio from mikes inside the astronauts` helmets and video from the camera into electronic impulses. These signals are added to a half watt radio beam, which is boosted to a 24 watt carrier beam and broadcast into space.
When it reaches the earth, the weak carrier beam from the moon is captured by dish antennas, 30 and 85 feet wide. But only the few 210 foot dishes can capture all the signals. The network allows for a global routing of data from these big
How are live pictures for Monday, March 29, 1971 dishes. Goldstone, California, may separate and amplify the sound signals from the carrier beam, while Canberra, Australia, treats the picture signals. Goldstone may transmit the sound data by coaxial cable to Mission Control in Houston. The picture data may be relayed to an orbiting satellite, beamed back to earth for transmission to Houston. The sound and picture signals are synchronized and sent to commercial networks. About four seconds after the events on the moon, the live TV program appears on our living room sets.
MFSN is a dramatic high speed operation. But the scope of its parent OTDA is stupendous. It relays world wide communications, weather and other data from satellites. And its future possibilities are beyond our most extravagant dreams.