Phobos program

The Phobos program was an uncrewed space mission with two probes sent by the Soviet Union to study Mars and its moon Phobos. The two spacecraft were called Phobos 1 and Phobos 2. They were built to learn more about the Red Planet and its smaller moon.

Phobos 1 was launched on July 7, 1988. Phobos 2 was launched five days later, on July 12, 1988. Sadly, Phobos 1 stopped working during its trip to Mars. Phobos 2 reached Mars and gathered important data, but we lost contact with it before it could finish all its work.

These spacecraft were a new, bigger design than earlier ones used to explore planets. Each one weighed about 2,600 kilograms, or more than 6,000 kilograms with its equipment. They were launched using strong Proton-K rockets. Many countries helped with this program, sharing their skills to explore our cosmic neighbor.

Objectives

The Phobos missions wanted to learn more about space between planets, watch the Sun, and study conditions around Mars. They also aimed to explore Mars' surface and atmosphere, and to discover what the moon Phobos is made of.

The missions planned to study the plasma around Mars and make detailed atmospheric observations of the planet.

Spacecraft design

The main part of the spacecraft had a round, sealed section for its electronic equipment. This section surrounded a tall, tube-like area for experiments. Below these parts were four round tanks that held a special fuel called hydrazine. This fuel helped control the spacecraft’s movement and adjust its path.

The spacecraft had 28 small engines for moving and balancing, plus more engines on its body and large solar panels that caught sunlight for power. It used a system to stay steady, guided by sensors that looked at the Sun and stars.

Phobos 1

Main article: Phobos 1

Phobos 1 was a space probe sent by the Soviet Union to study Mars and its moon Phobos. It worked well at first but stopped sending messages on September 2, 1988. This happened because of an error in the software loaded onto the spacecraft. The error made the probe shut off its control system, causing it to lose its position in space. Without this control, the probe could not keep its solar power panels facing the Sun, and its batteries ran out.

Phobos 2

Main article: Phobos 2

Phobos 2 was launched on July 12, 1988. It entered orbit around Mars on January 29, 1989. The probe worked well during its journey and when it reached Mars. It collected important information about the Sun, space between planets, Mars, and its moon Phobos. Phobos 2 studied Mars's surface and atmosphere. It sent back 37 detailed pictures of Phobos. Sadly, contact was lost before it could drop a small lander onto Phobos as planned.

Systems and sensors

The Phobos probes carried many tools to study Mars and its moon Phobos. They had special telescopes to look at the Sun’s x-rays and ultraviolet light. There was also a neutron spectrometer and a radar tool called Grunt to examine the surface of Phobos.

The landers on the probes included an x-ray/alpha spectrometer to learn about the chemicals on Phobos’ surface, and a seismometer to understand its inside structure. The Phobos 2 probe’s infrared spectrometer (ISM) collected images of Mars and Phobos, helping scientists make maps of their minerals and study Mars’ atmosphere. This tool was made at IAS and DESPA (Paris Observatory), with help from CNES.