“This picture of the Earth and Moon in a single frame, the first of its kind ever taken by a spacecraft, was recorded September 18, 1977, by NASA’s Voyager 1 when it was 7.25 million miles (11.66 million kilometers) from Earth. The moon is at the top of the picture and beyond the Earth as viewed by Voyager. In the picture are eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was directly above Mt. Everest (on the night side of the planet at 25 degrees north latitude) when the picture was taken. The photo was made from three images taken through color filters, then processed by the Image Processing Lab at Jet Propulsion Laboratory (JPL). Because the Earth is many times brighter than the Moon, the Moon was artificially brightened by a factor of three relative to the Earth by computer enhancement so that both bodies would show clearly in the prints. Voyager 1 was launched September 5, 1977 and Voyager 2 on August 20, 1977. JPL is responsible for the Voyager mission.”
27 August 1962: At 06:53:14 UTC (2:53 a.m., Eastern Daylight Time), Mariner 2 lifted off from Launch Complex 12 at Cape Canaveral Air Force Station, Florida, aboard an Atlas-Agena B launch vehicle. This was the second space probe to be sent to Venus.
Mariner 1 and 2 were identical space probes built by the Jet Propulsion Laboratory (JPL) of the California Institute of Technology (Caltech), Pasadena, California. The spacecraft were designed to obtain radiometric temperatures of Venus, and to measure the Interplanetary Magnetic Field.
The Mariner 1 mission failed when the launch vehicle veered off course and was destroyed by the Range Safety Officer, 4 minutes, 53 seconds into its flight, 22 July 1962.
The Atlas Agena B combined an Atlas LV-3A rocket with an Agena B upper stage. The Atlas was derived from the U.S. Air Force SM-65 Atlas intercontinental ballistic missile (ICBM), and was built by the Convair Division of General Dynamics at San Diego, California.
The height of the total vehicle, including the protective shroud encasing Mariner, 103 feet, 5 inches (31.70 meters). The Atlas Agena B first stage was 20.70 meters (67 feet, 11 inches) long, with a maximum diameter of 3.05 meters (10 feet). The maximum width across the booster section was 4.88 meters (16 feet).
The LV-3A is a “1-½ stage” liquid-fueled rocket with three engines. The “half-stage,” was a booster section consisting of two LR89-NA-5 rocket engines. This stage produced approximately 369,800 pounds of thrust (1,645 kilonewtons). The center, or “sustainer,” engine is a LR105-NA-5, rated at 86,800 pounds of thrust (386 kilonewtons). Both engines were built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California. The Atlas rocket used liquid oxygen and RP-1 (a highly-refined kerosene) propellant. The LV-3A had a total thrust of 456,587 pounds (2,031 kilonewtons).
The second stage was an Agena B, built by Lockheed Missiles and Space Systems, Sunnyvale, California. This engine was capable of being restarted in orbit. The Agena B was 7.20 meters (23 feet, 7 inches) long and had a maximum diameter of 1.50 meters (4 feet, 11 inches). It was also liquid fueled, but used a hypergolic mixture of nitric acid and UDMH. The single engine was a Bell Aerosystems Company LR81-BA-7, with 16,000 pounds of thrust (71.1 kilonewtons).
The Mariner probe was mounted atop the Agena second stage, enclosed in a protective shroud. Mariner had a gross weight of 447 pounds (202.8 kilograms). The probe was 9 feet, 11 inches long (3.02 meters) long, folded for launch, and 5 feet (1.52 meters) wide. When antennas and the solar panels were fully expanded, the spacecraft was 11 feet, 11 inches (3.63 meters) long and had a span of 16 feet, 6 inches (5.03 meters).
At liftoff, all three main engines were burning. After 2minutes, the two-engine booster assembly was jettisoned and the vehicle continued with the center LR105 sustainer. After 4 minutes, 25 seconds, this engine shut down and the Agena second stage separated. At this point, guidance was lost and the vehicle began to roll, but did not deviate significantly from the planned trajectory. About a minute later, guidance was restored and the mission continued.
The Agena B second stage placed the Mariner in a parking orbit at about 118 kilometers (73.3 miles) altitude. 16 minutes, 20 seconds later, the Agena engine was reignited and Mariner 2 was then placed on a trajectory planned to take it to Venus.
After 3 months, 17 days, at 19:59:28 UTC, 14 December 1962, the probe passed within 34,773 kilometers (21,607 miles) of Venus and measured the planet’s surface and cloud temperatures. It continued inward across the solar system and came within 105,464,560 kilometers (65,432,640 miles) of the sun.
The last transmission was received at 07:00 UTC, 3 January 1963, 129 days into the mission. Mariner 2 remains in orbit around the sun, circling every 292 days.
25 August 1981: 4 years, 5 days after launch from the Kennedy Space Center, Florida, Voyager 2 made its closest approach to Saturn.
The probe continued outward to Saturn, Neptune and Uranus, continuously transmitting images and data. In 1990, the space probe passed beyond the limits of the Solar System.
Voyager 2 is now in interstellar space. It crossed the heliopause, where “solar wind” is slowed by the pressure of interstellar gas, 5 November 2018. It is still operating, 46 years after it was launched.
On 21 July 2023, an erroneous instruction caused Voyager 2 to turn its antenna away from Earth, but on 5 August 2023, contact was reestablished. A power reduction strategy is hoped to allow the space probe to continue operating until 2026.
As of today, (24 August 2023) Voyager 2 is 133.6 Astronomical Units from Earth (19,990,415,757 kilometers/12,421,468,742 statute miles/10,793,960,992 nautical miles). Radio signals, traveling at the Speed of Light, take more than 18.5 hours to cross that distance. It continues outbound at a rate of 3.3 AU/year.
14 July 1965: At 0:00:57 p.m., Eastern Standard Time (01:00:57 UTC), 7 months, 14 days after its launch from the Kennedy Space Center, the space probe Mariner 4 made its closest approach to Mars. It came within 6,118 miles (9,846 kilometers) of the surface and took 21 full digital images and a portion of a 22nd. These images were stored on magnetic tape and later transmitted to Earth. 5.6 million bits of data were received.
Mariner 4 was a 260.68 kilogram (574.70 pounds) interplanetary spacecraft, controlled by radio signals from Earth. It was launched 28 November 1964 from Launch Complex 12 at the Kennedy Space Center, Cape Canaveral, Florida. The launch vehicle was a three-stage liquid-fueled Atlas D/Agena rocket.
Mariner 4 continued to perform experiments and send signals back to Earth until 21 December 1967. At that time, it was 192,100,000 miles (309,154,982.4 kilometers) from home. Today, it remains in orbit around the sun.