This is a 2 1/2 minute colour TV clip about the use of the National Aeronautics and Space Administration's USNS VANGUARD in an unusual marine geodetic experiment.
Close-up of Vanguard's bridge and aerial scene of ship
Map showing ship's position in Atlantic Ocean for normal support of Apollo
Artwork showing aerial view of Vanguard sailing over surface cavity and geodetic satellite orbiting overhead
Cut away art showing side view of the cavity over the bottom trench area
Pull away from art showing VANGUARD over the surface cavity area
Art showing the Geodetic satellite in orbit
Saturn V launch vehicle during launch.
View of VANGUARD's antennae.
Series of ship interior scenes showing faces and instrumentation
Tracking stations and interior of Apollo spacecraft showing astronauts
Script is copyright Reuters Limited. All rights reserved
Background: This is a 2 1/2 minute colour TV clip about the use of the National Aeronautics and Space Administration's USNS VANGUARD in an unusual marine geodetic experiment. Although normally used to support unmanned launches and to keep ground controllers in touch with the Apollo spacecraft during insertion into Earth orbit, the VANGUARD has been selected to work in tandem with a geodetic satellite to measure a huge cavity in the ocean surface. The cavity is directly above the five-mile deep Puerto Rico Trench, the deepest spot in the Atlantic.
A profile of the surface depression, can be determined by making radar range measurements between the satellite and the ship as the VANGUARD sails across the Puerto Rico Trench area.
A prime purpose of this unusual exercise is to provide a calibration standard for a sophisticated altimeter planned for use aboard a future geodetic satellite.
The VANGUARD is the single sea-going space link of NASA's Manned Space Flight Network, managed for NASA by its Goddard Space Flight Centre in Greenbelt, Maryland.
SYNOPSIS: This is the USNS Vanguard, NASA's single space link at sea, vital to the program of landing men on the Moon for exploration and returning them safely to Earth.
Generally stationed in the Atlantic, this ship supports numerous manned and unmanned launches from Cape Kennedy, Florida.
The Vanguard has now turned its space instrumentation to a more down-to-Earth problem near San Juan, Puerto Rico. It is helping to measure a huge depression, or cavity, in the surface of the Atlantic directly over the ocean's deepest spot -- the five mile deep Puerto Rico Trench.
Geodesists attribute the surface cavity to the unusual conditions of the ocean bottom and sub-surface mass in the trench area. These conditions deflect the vertical pull of gravity off centre. And since the sea level is always perpendicular to the real pull of gravity, a surface depression results.
Radar measurements between a geodetic satellite orbiting overhead and the ship as it sails over the Trench area will reveal the depth of the surface depression.
The measurements will contribute to the calibration of future geodetic satellites and further provide vital information to improve ocean mapping navigation. The ocean areas are the least known and pose the greatest problem to geologists.
For the Apollo mission, the VANGUARD's prime task is to help verify that the spacecraft is safely inserted into Earth orbit.
Shortly after liftoff, VANGUARD's array of antennae begin to receive enormous quantities of information from the launch vehicle and the Apollo spacecraft.
Launch vehicle performance data is recorded, processed by VANGUARD's computers and relayed to mission controllers in Houston.
Additional telemetry indicates the status of the spacecraft's systems and the condition of the astronauts.
Voice communications with the crew are checked.
Data from VANGUARD and other land stations in NASA's Manned Space Flight Network enable flight controllers in Houston, Texas, to confirm a "go" for earth orbit, the first step in the Apollo flight to the Moon.
The global Apollo tracking network consists of the VANGUARD and 12 land stations. NASA's Goddard Space Flight Centre near Washington, D.C., maintains and operates the Network as a vital electronic link to guide the Apollo spacecraft and its three-man crew to the Moon and safely return them to Earth.