GRACE-FO 1 & FO 2

Launch data:

Spacecraft data:

Description:

• GRACE-FO 1 and GRACE-FO 2 are two identical Earth science satellites with primary research objective focused on gravity measurements and Earth′s water cycle. Built by Airbus Defense and Space, the identical GRACE-Follow On satellites carry microwave ranging instruments to measure the separation between the craft as they fly around 137 miles (220 kilometers) apart in orbit. The ranging sensors require exacting precision, with the capability of measuring distance changes between the formation-flying satellites as small as a few microns—about the width of a blood cell. Changes in the range between the two GRACE-Follow On satellite will be caused by tiny variations in the pull of gravity from Earth below, telling scientists about the mass of water, rock and ice around the world.

Mission details:

• SpaceX carried out the 6th Iridium-Next launch from Vandenberg on May 22, 2018. First, the Falcon 9 second stage dropped off two scientific payloads in a 500 km circular orbit.
• The GRACE-FO (Gravity Recovery and Climate Experiment, Follow-on) satellites replace GRACE 1 and 2 which were launched in 2002 and re-entered a few months ago, and will detect subtle changes in the local gravitational field due to shifts in the oceans. The GRACE mission is led by JPL and Germany′s Geoforschungszentrum Potzdam (GFZ).

External links:

• Satellite tracking: Real time satellite tracking