The Magellan Mission

Venus is the second planet from the sun. It can be found in between Mercury and Earth in the solar system. Its rotation period is 243 days, which is the longest rotation period of any other planet in the solar system. Venus also rotates in the opposite direction to most planets. Venus is named after the Roman goddess of love and beauty because it shined the brightest of all five planets known to early astronomers. Venus is also the second brightest natural object in the sky.

Venus’s atmosphere is made of 96.5% carbon dioxide and 3.5% nitrogen. Sulfuric acid clouds plague Venus’s skies and are made up of sulfur dioxide drops and sulfuric acid drops. These clouds reflect roughly 75% of Venus’s sunlight. The atmosphere is heavier than that of any other planets atmosphere. It's surface pressure is 90 times more than Earth’s. Previous probes on Venus have only survived a few hours before being destroyed. These probes either melted or were crushed by the surface pressure.

Twenty previous spacecraft from the U.S. and U.S.S.R. had already probed Venus' surface before the Magellan mission. The high-pressure atmosphere crushed the Soviets' early Venera craft. Later models managed to survive the pressure and land on Venus’ surface. These models were equipped with instruments to see the surface, but these instruments could only see features larger than a kilometer. In the early 1980s, orbiters from America and Soviet created the first global radar maps of Venus.

In the late 1970s, scientists tried creating a new radar mapping mission to Venus. They first set out to create a spacecraft named the Venus Orbiting Imaging Radar (VOIR), but the scientists soon realized there would be too many budget problems. In 1982, the VOIR mission was canceled.

The Magellan Mission was a simplified radar mission recommended by the Solar System Exploration Committee. It was submitted and accepted as the Venus Radar Mapper program in 1983. This was the beginning of the Magellan Mission.

Most of the Magellan probe was created from previous missions spare parts to save costs. This included, but was not limited to, the Voyager program, Galileo, and Mariner 9. A spare body from the Voyager missions was used as the body of the spacecraft. It was basically a 10-sided aluminum bus, which contained the computers, data recorders, and other subsystems. Overall, the probe weighed 3,449 kilograms. The probe was a total of 15.4 feet long, topped with a 12 foot long antennae. Giraffes generally are 18 feet tall. An adult male hippo typically weighs 1,600 to 4,500 kg. It’s like they sent a computer filled hippo that was as tall as a giraffe to Venus.

The Magellan achieved many scientific firsts. It was the first interplanetary mission to be launched from the Space Shuttle. The Space Shuttle was the world’s first reusable spacecraft. The Magellan Mission was also the first mission to use the Inertial Upper Stage booster for launching. The Inertial Upper Stage booster was a rocket used send its payload into a higher orbit or sending probes through space. It was also the first mission to use the aerobraking as an orbiting method. This caused the spacecraft to slow down by flying through a planet’s atmosphere to slow down.

Magellan’s main objectives were to study landforms and tectonics, erosion, deposition, chemical processes, and to model the interior of Venus. The Magellan also needed to create quality radar maps of Venus’s surface, which would hopefully provide a clear look at the planet's surface under the thick cloak of clouds that in case the planet. The scientist at NASA was hoping to map at least 70% of the planet. A radar map is a type of radar used to locate precipitation, calculate its motion, and estimate its type.

The Magellan spacecraft launched on May 4, 1989. It was launched by the National Aeronautics and Space Administration from the KSC Launch Complex at the Kennedy Space Center in Florida.

On August 10, 1900, the Magellan probe landed on Venus after traveling 1.3 billion kilometers (or 806 million miles). It also orbited around the sun one and a half times.

Yes. The Magellan mission created quality radar maps of 98% of Venus’s surface at a resolution of 100 to 150 meters using a using synthetic aperture radar that simulates the use of a large radar antenna. The synthetic aperture radar was used to reduce costs.

It was also found that 85% of the planet's surface is covered with volcanic flows and there’s evidence of tectonic movement. The Magellan also produced high-resolution gravity data for 95% of the planet. While producing this data, a new maneuvering technique called aerobraking, which uses the atmospheric drag to adjust an items orbit was tested.

A commonly asked question is “how did the Magellan take pictures through Venus’ thick clouds?” Well, the probe used very long radio waves that could easily pass through the clouds. Radio waves were used because light waves cannot penetrate the clouds. The radio waves reflected off of the ground, which revealed surface details such as craters, canyons, cliffs, lava flows, and volcanoes. Basically, everything was reflected back up the probe and then recorded.

Venus has more volcanoes covering its surface than any other planet in our solar system. Although it’s covered in volcanoes, none of them are currently active. Over 1600 prominent volcanic features or volcanoes make up Venus’ surface. There are many many smaller volcanoes, but they have yet to be counted. It is estimated that there are hundreds of thousands of small domes. Each dome or volcano ranges from two to three kilometers across and one hundred kilometers tall.

When you think of volcanoes, you typically think of tall mountain like monsters spewing out lava. There are many tall mountains like volcanic monsters on Venus, but none of them are spewing out lava. Besides from the small dome-like volcanoes and the mega-monsters, there are pancake-like puddles that also cover Venus. These pancake like puddles are mainly 25-kilometers less than 1.6 kilometers tall. These puddles were created where thick, sticky lava oozed out of the surface and solidified.

Six days after entering orbit, the Magellan suffered a communications outage that lasted 15 hours. Almost a week after entering orbit, the Magellan probe slipped behind the planet and lost communication with the technicians at the Jet Propulsion Laboratory. Communication was lost for almost 37 minutes until the probe emerged from behind the planet. After another 17-hour interruption on August 21, new preventative software was sent up to reset the system, in case another mishap like this were to occur again.

After the deterioration of the power output from the solar arrays and onboard components, it was decided the Magellan mission would be terminated. Since the mission had reached all of its goals, there was no longer a reason for it to map the surface. The mission was scheduled to end in mid-October. The preparation to end the Magellan was started in late August of 1994. There was a series of orbital trim maneuvers that lowered the probe into the outermost layers of Venus’ atmosphere. On October 13, 1994, all communication was lost. And that’s the end of the Magellan mission.

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