Tag Archives: Interplanetary Probe

27 August 1962, 06:53:14 UTC, T minus Zero

Engine ignition of Mariner 2 Atlas Agena B at LC-12, Cape Canaveral AFS, 2:53 a.m., EST, 27 August 1962. (NASA)

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.

Mariner 2 under final inspection. (NASA)

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).

Artist's conception of Mariner 2 in interplanetary space. (NASA)
Artist’s conception of Mariner 2 in interplanetary space. (NASA)

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.

Mariner 2, carried alloft by Atlas LV3 179D, accelerates past the gantry, 06:53 UTC, 26 August 1962 (NASA)
The Atlas Agena B, carrying Mariner 2, accelerates toward orbit, 06:53 UTC, 27 August 1962 (NASA)

© 2018, Bryan R. Swopes

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14 July 1965

Mariner 4 (JPL/NASA)

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.

Mariner 4 digital image of Mars surface, 14 July 1965. (NASA)

© 2018, Bryan R. Swopes

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25 January 2004, 05:05 UTC SCET

"The interior of a crater surrounding the Mars Exploration Rover Opportunity at Meridiani Planum on Mars can be seen in this color image from the rover's panoramic camera. This is the darkest landing site ever visited by a spacecraft on Mars. The rim of the crater is approximately 10 meters (32 feet) from the rover. The crater is estimated to be 20 meters (65 feet) in diameter. Scientists are intrigued by the abundance of rock outcrops dispersed throughout the crater, as well as the crater's soil, which appears to be a mixture of coarse gray grains and fine reddish grains. Data taken from the camera's near-infrared, green and blue filters were combined to create this approximate true color picture, taken on the first day of Opportunity's journey. The view is to the west-southwest of the rover."
“The interior of a crater surrounding the Mars Exploration Rover Opportunity at Meridiani Planum on Mars can be seen in this color image from the rover’s panoramic camera. This is the darkest landing site ever visited by a spacecraft on Mars. The rim of the crater is approximately 10 meters (32 feet) from the rover. The crater is estimated to be 20 meters (65 feet) in diameter. Scientists are intrigued by the abundance of rock outcrops dispersed throughout the crater, as well as the crater’s soil, which appears to be a mixture of coarse gray grains and fine reddish grains. Data taken from the camera’s near-infrared, green and blue filters were combined to create this approximate true color picture, taken on the first day of Opportunity’s journey. The view is to the west-southwest of the rover.” (NASA Jet propulsion Laboratory)

25 January 2004: Mars Exploration Rover–B, named Opportunity, landed at Meridiani Planum on the surface of Mars at 5:05 a.m., UTC SCET (Spacecraft Event Time) and rolled into a small crater, approximately 22 meters (72 feet) in diameter.

Meridiani Planum is near the center of this image of Mars, photographed from the Mars Orbiter Mission, 28 September 2014, at an altitude of 74,582 kilometers (46,343 miles). (The Bruce Murray Space Image Library)

The crater would later be named Eagle Crater, and the landing site is named Challenger Memorial Station. The site is on the opposite side of the planet from Opportunity‘s twin, MER-A, Spirit.

“This image taken by the panoramic camera onboard the Mars Exploration Rover Opportunity shows the rover’s now-empty lander, the Challenger Memorial Station, at Meridiani Planum, Mars. The image was acquired on the 24th martian day, or sol, of Opportunity’s mission at approximately 13:00 Local Solar Time. This is a mosaic image consisting of 12 color images acquired with the camera’s red, green and blue filters. The color balance has been set to approximate the colors that a human eye would see.” (NASA/JPL/Cornell)
Artist’s conception of a NASA Mars Exploration Rover on the surface of Mars. (JPL)

© 2018, Bryan R. Swopes

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