Mariner program

The Mariner program was a group of space missions led by NASA to explore other planets. Between 1962 and 1973, scientists at NASA's Jet Propulsion Laboratory created 10 robotic space machines called Mariner. These machines traveled to planets like Venus, Mars, and Mercury for the very first time, and they went back to these planets to learn even more.

The Mariner program achieved many amazing "firsts" in space travel. It included the first successful flyby of a planet, the first spacecraft to orbit a planet, and the first use of a gravity assist maneuver. Out of the 10 Mariner spacecraft, seven worked well and helped start many more space missions by NASA and Jet Propulsion Laboratory. The ideas from Mariner were used to create other famous missions like the Voyager program, Viking program, Galileo, and Magellan.

The whole Mariner program cost about $554 million. These missions helped us learn a lot about our solar system and inspired many more exciting space adventures.

Early concept

The Mariner program started in 1960 with plans for small, frequent missions to explore nearby planets. These missions would use new Atlas rockets and JPL’s growing network of ground stations for talking to spacecraft far away. The program was named Mariner in May 1960, inspired by sea travel, to give the idea of journeying to distant places.

Each Mariner spacecraft was built to carry solar panels facing the Sun and an antenna pointing to Earth. They also carried many scientific tools, like cameras for studying planets and instruments to measure things like magnetic fields. The designers planned for the Mariners to stay steady in three directions instead of spinning. For extra safety, each mission had two spacecraft ready to launch on different rockets. Although some early missions, like Mariner 1, Mariner 3, and Mariner 8, were lost during launch, their backup spacecraft succeeded. Later missions reached their targets and finished their science work successfully.

Basic layout

All Mariner spacecraft had a special shape, either six-sided or eight-sided, that held all the electronic parts. Things like antennas, cameras, and power sources were attached to this shape. Mariner 2 was built using parts from the Ranger Lunar probe. Most of the later Mariners had four solar panels to make power, but Mariner 10 only had two. Also, most of them had TV cameras, except for Mariner 1, Mariner 2, and Mariner 5.

The first five Mariners flew using Atlas-Agena rockets, but the last five used Atlas-Centaur rockets. After Mariner 10, the probes used Titan IIIE, Titan IV rockets, or the Space Shuttle with a special upper stage for their journeys. These journeys sometimes used the gravity of planets to help them move faster.

Mariners

The Mariners were small robots sent into space by NASA. They were launched on Atlas rockets and were very light, weighing less than half a ton without fuel. Each mission lasted from a few months to a couple of years, and one kept sending back important science information for three years after its original mission ended.

Mariners 1 and 2

Main articles: Mariner 1 and Mariner 2

Mariner 1 and Mariner 2 were two space probes created by NASA to study the planet Venus. Mariner 1 was launched on July 22, 1962, but it did not reach space because of a problem with its rocket. Mariner 2 was launched on August 27, 1962, and it successfully flew by Venus after a journey of 3½ months, making it the first spacecraft to fly by another planet.

During its trip, Mariner 2 made important discoveries. It measured the solar wind—the steady flow of particles from the Sun—for the first time. It also studied tiny particles from space and high-energy particles from the Sun. When it reached Venus on December 14, 1962, Mariner 2 used special tools to learn about the planet’s clouds and surface, discovering that Venus has very hot temperatures hidden under its thick clouds.

• Mission: Venus flyby
• Mass: 203 kg (446 lb)
• Sensors: microwave and infrared radiometers, cosmic dust, solar plasma and high-energy radiation, magnetic fields

Status:

• Mariner 1 – Destroyed shortly after liftoff.
• Mariner 2 – No longer working after its successful mission, continues to travel around the Sun.

Mariners 3 and 4

Main articles: Mariner 3 and Mariner 4

Mariner 3 and Mariner 4 were missions to fly by the planet Mars.

Mariner 3 was launched on November 5, 1964, but it did not reach Mars because a part of its rocket did not open correctly.

Mariner 4 was launched on November 28, 1964, and became the first spacecraft to successfully fly by Mars. It flew past Mars on July 14, 1965, and sent back the first close-up pictures of the planet. These pictures showed craters on Mars, some of which had frost on them. Mariner 4 continued to work for about three years after its mission ended, studying the space around the Sun.

The spacecraft carried a camera and other tools to study Mars and the space environment.

Mariner 5

Main article: Mariner 5

The Mariner 5 spacecraft was sent to Venus on June 14, 1967 and reached the planet in October 1967. It carried tools to study Venus's atmosphere using radio waves, look at its brightness in ultraviolet light, and check solar particles and magnetic field changes above the planet.

• Mission: Venus flyby
• Mass: 245 kg (540 lb)
• Sensors: ultraviolet photometer, cosmic dust, solar plasma, trapped radiation, cosmic rays, magnetic fields, radio occultation and celestial mechanics

Status: Mariner 5 – No longer working and now moves around the Sun in a heliocentric orbit.

Mariners 6 and 7

Main article: Mariner 6 and 7

Mariners 6 and 7 were two identical spacecraft sent to study Mars. Mariner 6 launched on February 24, 1969, and Mariner 7 followed on March 21, 1969. They flew over Mars’ equator and southern hemisphere, using sensors to examine the planet’s atmosphere and surface. They also captured and sent back many pictures. Although they missed some major features like large volcanoes and a grand canyon, their images confirmed dark patterns that people had seen from Earth but did not show any canals.

Both spacecraft are no longer working and are now moving around the Sun in a heliocentric orbit.

Mariners 8 and 9

Main articles: Mariner 8 and Mariner 9

Mariner 8 and Mariner 9 were built to map the surface of Mars at the same time. However, Mariner 8 did not make it into space because of a problem with the rocket that launched it. Mariner 9 was launched in May 1971 and became the first spacecraft to orbit Mars. It carried special tools to study the planet’s surface and atmosphere.

Mariner 9 used cameras and sensors to take pictures and gather information about Mars. It waited for dust storms to clear before taking detailed photos of the planet’s surface. It was also the first to capture close images of Mars’s small moons, Phobos and Deimos.

Mariner 10

Main article: Mariner 10

The Mariner 10 spacecraft launched on November 3, 1973. It was the first to use the gravity of a planet to change its path. As it passed by Venus, the planet's gravity helped push it toward Mercury. This was also the first spacecraft to get close to two planets. For 33 years, it was the only spacecraft to take close pictures of Mercury.

Because of the way Mercury spins, Mariner 10 could only see half of the planet during its visits. It visited every six months, taking pictures and collecting information about Mercury's surface.

The mission studied things like particles around the planets, magnetic fields, and how radio waves passed through the planets' atmospheres.

Status: Mariner 10 – No longer working and now moving around the Sun in a heliocentric orbit.

Mariner Jupiter-Saturn

Main article: Mariner Jupiter-Saturn

Mariner Jupiter-Saturn was approved in 1972 after the cancellation of the Grand Tour program. This program planned two space probes to visit the two large gas planets, Jupiter and Saturn. The designers built the spacecraft with the idea that they could also visit more planets later if needed. One probe was planned to visit Jupiter and Saturn first and then fly by Saturn's moon Titan to learn about its thick atmosphere. The other probe would visit Jupiter and Saturn after the first one, and could then go on to Uranus and Neptune if the first probe succeeded, or also fly by Titan if needed. The program was renamed Voyager just before it launched in 1977. After Voyager 1 completed its flyby of Titan, Voyager 2 went on to visit the two ice giants.