September 3rd - Cape Canaveral - (INN)
Cape Canaveral, Florida -- "Today, the United States launched Explorer 1, mankind's first orbiting satellite." Director Dickinson announced in a media-filled press conference. President Eisenhower released a statement reaffirming his confidence in the NASA Director, and feels the future is bright for the US space effort under the Director's guidance.
"The Juno I rocket was launched September 3rd, putting Explorer 1 into orbit with a perigee of 222 miles and an apogee of 1,580 miles, having an orbital period of 114.8 minutes. Once Explorer 1 was confirmed to be in orbit, we called this news conference, here at the National Academy of Sciences in Washington, DC and announced it to the world.
"Explorer 1 was designed and built by the California Institute of Technology's Jet Propulsion Laboratory under the direction of Dr. William H. Pickering. It is the first satellite to carry a mission payload.
"The total weight of the satellite is 30.80 lbs, of which 18.3 lbs are part of the instrumentation package. The instrument section at the front end of the satellite and the empty scaled-down fourth-stage rocket casing orbit as a single unit, spinning around its long axis at 750 revolutions per minute.
"Data from the satellite is transmitted to the ground by two antennas. A 60 milliwatt transmitter feeds a dipole antenna, consisting of two fiberglass slot antennas in the body of the satellite, operating on 108.03 MHz, and four flexible whips forming a turnstile antenna are fed by a 10 milliwatt transmitter operating on 108.00 MHz.
"Because of the limited space available and the requirements for low weight, the payload was designed and built with simplicity and high reliability in mind, using new transistor based electronics, consisting of both germanium and silicon devices. A total of twenty-nine transistors are used in Explorer 1. Electrical power is provided by mercury chemical batteries that make up approximately forty percent of the payload weight.
"The external skin of the payload section is painted in alternating stripes of white and dark green to provide passive temperature control of the satellite. The proportions of the light and dark stripes were determined by studies of shadow-sunlight intervals based on firing time, trajectory, orbit, and inclination.
After the press conference was completed Director Dickinson released the following information on the first manmade object to orbit our planet.
David Richlen
Science Desk, International News Network
Statistics on the rocket and satellite:
The Juno I consists of a Jupiter-C rocket, with a fourth stage mounted on top of the tub of the third stage, which is fired after the third stage burnout, to boost the payload and fourth stage to an orbital velocity of 18,000 mph.
This multi-stage system, designed by Wernher von Braun for his proposed Project Orbiter, obviated the need for a guidance system in the upper stages, proving to be the simplest and most immediate method for putting a payload into orbit. Both the four stage Juno I and three stage Jupiter-C launch vehicles are the same height, with the added fourth stage booster of the Juno I being enclosed inside the nose cone of the third stage.
SizeHeight: 69.5 feet
Diameter: 5.8 feet
Mass: 64,070 lb
Stages: 4
Capacity Payload to LEO: 42 lbs
PerformanceFirst Stage: Redstone (stretched)
Engines: 1x Rocketdyne A-7
Thrust: 93,562 lbf
Specific Impulse: 235 sec
Burn Time: 155 seconds
Fuel: Hydyne/LOX
Second Stage: MGM-29 Sergeant cluster
Engines: 11 Solid
Thrust: 16,490 lbf
Specific Impulse: 214 sec
Burn Time: 6 seconds
Fuel: Solid - polysulfide-aluminum and ammonium perchlorate
Third Stage: MGM-29 Sergeant cluster
Engines: 3 Solid
Thrust: 4,500 lbf
Specific Impulse: 214 sec
Burn Time: 6 seconds
Fuel: Solid - polysulfide-aluminum and ammonium perchlorate
Fourth Stage: MGM-29 Sergeant
Engines: 1 Solid
Thrust: 1,499 lbf
Specific Impulse: 214 sec
Burn Time: 6 seconds
Fuel: Solid - polysulfide-aluminum and ammonium perchlorate
Explorer-1Operator: Army Ballistic Missile Agency
Major contractors: Jet Propulsion Laboratory
Mission type: Earth science
Launch date: 3 September, 1956 at 05:16 UTC
Launch vehicle: Juno-II
Mass: 90 lbs
Orbital elements Eccentricity: 0.139849
Inclination: 33.24°
Apogee: 1,580 miles (2,550 km)
Perigee: 222 miles (358 km)
Orbital period: 114.8 minutes