The ESAIL EU FP7 project (2011-2013) developed laboratory prototypes (TRL 4-5) of the key components of the E-sail. The project involved five countries, nine institutes and had a EU contributed budget of about 1.7 million euros.
The ESTCube-1 satellite was launched on May 7 2013 to polar sun-synchronous 667 km orbit from the European Spaceport in Kourou, French Guiana. ESTCube-1 is a 1U CubeSat and Estonia's first satellite. Its main task is to measure the strength of the E-sail effect in low Earth orbit. ESTCube-1 will deploy a 10 m long tether and charge it up which allows us to measure the E-sail force exerted on the tether by the ionospheric ram flow acting on the satellite. We use the ionospheric ram flow as a substitute for the solar wind to be able to measure the E-sail effect (Coulomb drag) at low cost in low Earth orbit.
The progress of the ESTCube-1 mission can be followed on its Facebook page. An ESTCube special issue was published in May 2014 with 9 technical peer-reviewed articles.
There will be a 100 m long test tether onboard the Aalto-1 satellite, to be launched in 2014.