Hi EQF. I’m not sure that I understand what you mean by earths acceleration in space. If you are referring to the earth’s orbit around the sun the speed of the earth varies depending upon its location in relation to the sun however, this value is almost always the same approximate number.

In the earth's orbit around the sun, it travels at an average speed of 29.658 km/s. When the earth is closest to the sun, which is called the perihelion it will have its greatest orbital speed around January 3. When it is farthest from the sun, which is called the aphelion it will have its least orbital speed around July 4. Since equal areas must be covered in equal intervals of time, the planet's orbit speed has to be the fastest at perihelion and slowest at aphelion.

If the acceleration is something other then what I have pointed out you will have to explain the cause of that acceleration and how it is measured. Take Care…Don in creepy town