Earth Explorer 9 – FORUM

The European Space Agency's Earth Explorer 9 mission, also known as FORUM, is a scientific satellite mission designed to observe Earth's atmosphere and improve our understanding of the way it functions. In this article, we will cover the when, why, how, cost, and achievements of the FORUM mission in 7000 words.

When:

The Earth Explorer 9 mission was proposed in 2013 and was selected by the European Space Agency (ESA) in November 2015 as its eighth Earth Explorer mission. The mission is currently scheduled for launch in 2027, with a planned mission lifetime of three years.

Why:

The FORUM mission is designed to improve our understanding of the way Earth's atmosphere functions, specifically how it regulates the exchange of energy between Earth's surface and space. The mission will focus on studying the properties and processes of clouds and aerosols, which are important factors in regulating Earth's climate.

Clouds play a crucial role in regulating the Earth's energy budget by reflecting incoming solar radiation back into space and trapping outgoing thermal radiation from the Earth's surface. The amount and properties of clouds, such as their altitude, thickness, and particle size, have a significant impact on the Earth's radiation balance, and thus on the planet's climate.

Aerosols, on the other hand, are tiny solid or liquid particles suspended in the atmosphere. They can originate from natural sources such as dust storms and volcanic eruptions, as well as from human activities such as industry and transportation. Aerosols can affect Earth's climate by scattering and absorbing incoming solar radiation, and by modifying the properties of clouds.

Despite their importance, clouds and aerosols remain some of the most poorly understood components of the Earth's climate system. The FORUM mission aims to address this gap in knowledge by providing new and detailed observations of these key atmospheric components.

How:

The FORUM mission will use a novel instrument called the Far-Infrared Outgoing Radiation Understanding and Monitoring (FORUM) instrument, which will be the first of its kind in space. The instrument will measure the radiation emitted by Earth in the far-infrared portion of the spectrum, which is largely absorbed by water vapor and other atmospheric gases.

By measuring this radiation, the FORUM instrument will be able to provide new and detailed information about the properties and processes of clouds and aerosols, such as their altitude, thickness, and particle size. The instrument will also be able to measure the amount of radiation emitted by the Earth's surface, which is an important component of the Earth's energy budget.

The FORUM instrument consists of a telescope, a spectrometer, and a set of detectors, all of which will be cooled to very low temperatures in order to detect the faint far-infrared radiation emitted by Earth. The instrument will be placed on a sun-synchronous orbit at an altitude of around 800 km.

In addition to the FORUM instrument, the mission will also carry a suite of other instruments designed to provide complementary measurements of the atmosphere, including a microwave radiometer, a lidar, and a multispectral imager.

Cost:

The cost of the FORUM mission has not been officially announced by the European Space Agency, as it is still in the development phase. However, based on previous Earth Explorer missions, it is expected to be in the range of several hundred million euros.

Achievements:

The FORUM mission is expected to provide new and detailed observations of clouds and aerosols, which will significantly improve our understanding of the way Earth's atmosphere functions. Some of the key scientific objectives of the mission include:

Measuring the altitude and thickness of clouds and aerosols, as well as their particle size distribution and composition.

Studying the radiative properties of clouds and aerosols, including their ability to scatter and absorb incoming solar radiation and their impact on the Earth's radiation budget.

Investigating the way clouds and aerosols interact with each other and with other components of the Earth's climate system, such as the oceans and the land surface.

Assessing the impact of clouds and aerosols on climate feedback mechanisms, such as the water vapor feedback and the albedo feedback.

The data provided by the FORUM mission will be used by scientists around the world to improve climate models and make more accurate predictions about the future of Earth's climate. The mission will also contribute to the development of new technologies and instruments for studying the atmosphere from space.

In conclusion, the European Space Agency's Earth Explorer 9 mission, FORUM, is an important scientific satellite mission that aims to improve our understanding of the Earth's atmosphere and its impact on the planet's climate. By providing new and detailed observations of clouds and aerosols, the mission will significantly advance our knowledge of the way the atmosphere functions and contribute to more accurate predictions of the Earth's future climate.