New satellite to be launched for high-res gravity measurements

ESA is launching a new satellite to measure gravity variations around the earth in unprecedented detail. The data collected by the satellite will make it possible to measure the exact height from the surface at any pint on earth. In order to limit mechanical noise, it uses ion engines for thrust. Plus, it looks like it is actually made to travel in space :)  [Link]

As Goce bumps through the Earth's gravity field, the accelerometers will sense the fantastically small disturbances.

"We have one comparison that we often make," explained Rune Floberghagen, Esa's Goce mission manager.

"Imagine a snowflake, which has a fraction of a gram, slowly falling down on to the deck of a supertanker. The acceleration that the supertanker experiences from that snowflake is comparable to the sensitivity of our instrument,"

 

 

1. The 1,100kg Goce is built from rigid materials and carries fixed solar wings. The gravity data must be clear of spacecraft 'noise'
2. Solar cells produce 1,300W and cover the Sun-facing side of Goce; the near side (as shown) radiates heat to keep it cool
3. The 5m-by-1m frame incorporates fins to stabilise the spacecraft as it flies through the residual air in the thermosphere
4. Goce's accelerometers measure accelerations that are as small as 1 part in 10,000,000,000,000 of the gravity experienced on Earth
5. The UK-built engine ejects xenon ions at velocities exceeding 40,000m/s; Goce's mission will end when the 40kg fuel tank empties
6. S Band antenna: Data downloads to the Kiruna (Sweden) ground station. Processing, archiving is done at Esa's centre in Frascati, Italy
7. GPS antennas: Precise positioning of Goce is required, but GPS data in itself can also provide some gravity field information