FLEX Mission

FLEX mission provides global maps of vegetation fluoresce

nce that can reflect photosynthetic activity and plant health and stress. This is not only important for a better understanding of the global carbon cycle, but also for agricultural management and food security. This is of particular relevance due to demand the growing world population is placing on the production of food.

Currently it is not possible to measure photosynthetic activity from space, but FLEX’s novel instrument is capable of achieving this. The mission was selected as the eighth Earth Explorer in ESA’s Living Planet Programme in 2015.

FLEX flies in tandem with the Copernicus Sentinel-3 mission, in particular working in combination with the OLCI and SLSTR instruments Sentinel-3 carries.

FLEX will operate in a Sun-synchronous orbit at an altitude of 814 km, with an inclination of 98.64° and a 27-day repeat cycle.

A series of ground facilities will support the mission:

• Mission control: ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany. Additionally, the tandem operations with Copernicus Sentinel-3 will be coordinated with EUMETSAT
• Communication links: X-band science data via Svalbard and Norway, and S-band telemetry via Kiruna in Sweden

Data: ESA’s Centre for Earth Observation (ESRIN) in Frascati, Italy

The FLEX mission consists of a single three-axis stabilized satellite flying in tandem with Copernicus Sentinel-3 to make optimal use of existing relevant space observation capabilities, providing a suite of complementary measurements acquired within 6 – 15 seconds of each other in order to minimize the effects of moving clouds. It is expected that FLEX will orbit 100 km ahead of one of the Sentinel-3 satellites.

The FLEX satellite configuration designs are based on careful consideration of:

• Accommodation of the FLORIS payload so the instrument has an unobstructed view of the Earth
• Pointing and co-registration requirements, which favour the isostatic mounting of the instrument on a specific payload support panel
• Line of sight stability
• Vega launcher fairing envelope, limiting the size and shape of the instrument and overall satellite
• The FLEX satellite will be 1.5 x 1.2 x 1.2 m in size, and when in orbit will deploy two solar array panels, resulting in a total width of 5.2 m. The satellite will have a mass of approximately 460 kg (including 140 kg instrument and 30 kg propellant).