Mission 1 – Gaia

The European Space Agency (ESA) launched its Gaia spacecraft in December 2013, with the goal of creating a 3D map of the Milky Way galaxy. The mission is part of the broader ESA science program and is designed to help scientists better understand the structure, evolution, and dynamics of the Milky Way.

When:

The idea for the Gaia mission was first proposed in the 1990s, but it wasn't until 2000 that the mission was formally approved by ESA. The spacecraft was then launched on December 19, 2013, from the Guiana Space Centre in French Guiana.

Why:

The Gaia mission has several scientific objectives, including measuring the position, brightness, and motion of more than one billion stars in the Milky Way. The spacecraft also collects data on other astronomical objects, such as asteroids, quasars, and supernovae. By analyzing this data, scientists hope to answer some of the most fundamental questions about the origins and evolution of the Milky Way.

One of the key goals of the Gaia mission is to create a precise 3D map of the Milky Way galaxy. This map will allow scientists to study the distribution of stars and other astronomical objects, as well as their movements and interactions. By analyzing this data, scientists hope to better understand the structure and dynamics of the Milky Way, including the way in which it formed and how it has evolved over time.

Another important goal of the Gaia mission is to study the properties of individual stars in the Milky Way. By measuring the brightness and motion of more than one billion stars, the mission will help scientists better understand the physical characteristics of stars, such as their mass, temperature, and age. This information will be invaluable for studying the origins and evolution of the Milky Way.

How:

The Gaia spacecraft is a complex piece of technology that uses a variety of instruments to collect data on astronomical objects. The spacecraft is equipped with two telescopes that are used to observe stars and other objects in the Milky Way. The telescopes work together to create a 3D map of the galaxy, using a process called astrometry.

Astrometry involves measuring the precise positions of stars in the sky, as well as their movements over time. To do this, the Gaia spacecraft uses a device called a micro-arcsecond astrometric instrument (MAI). This instrument is capable of measuring the position of a star to an accuracy of about 20 micro-arcseconds, which is roughly equivalent to the size of a dime seen from 1000 kilometers away.

In addition to astrometry, the Gaia spacecraft also collects data on the brightness and color of stars using a device called a photometer. The photometer is capable of measuring the brightness of a star to an accuracy of about one part in a million, which is essential for studying the physical properties of stars.

Cost:

The Gaia mission is one of the most ambitious and expensive space science projects ever undertaken by ESA. The total cost of the mission is estimated to be around 740 million euros ($850 million USD), which includes the cost of developing and launching the spacecraft, as well as the cost of operating it during its expected lifetime of five years.

Achievement:

The Gaia mission has already achieved some impressive scientific milestones since its launch in 2013. One of the most significant achievements of the mission was the release of the Gaia Data Release 2 (DR2) in April 2018. This release included detailed information on the position, brightness, and motion of more than 1.7 billion stars in the Milky Way, making it the largest and most precise 3D map of our galaxy ever created.

The data from the Gaia mission has already led to some groundbreaking discoveries in the field of astrophysics. For example, the mission has helped scientists better understand the structure and evolution of the Milky Way, including the way in which it was formed and how it has evolved over time. The data has also been used to study the distribution and movement of stars in our galaxy, revealing previously unknown patterns and structures.

In addition to its work on the Milky Way, the Gaia mission has also collected data on other astronomical objects, such as asteroids, quasars, and supernovae. This data has been used to study the properties of these objects in greater detail, providing new insights into the nature of the universe.

Looking forward, the Gaia mission is expected to continue producing groundbreaking science for years to come. In the coming years, the mission will release additional data sets that will provide even more detailed information on the Milky Way and other astronomical objects. This data will help scientists continue to unravel the mysteries of the universe and better understand our place within it.