"NASA's Gravity Probe B spacecraft could begin testing Einstein's general theory of relativity as early as this week, according to mission controllers at Stanford University.But they were able, through excellent redundancies built into the probe, overcome these issues.
The probe, said to be one of the most precise scientific instruments ever assembled, was initially scheduled to begin taking measurements within 45 to 60 days of its April 20 launch into Earth orbit. But mission controllers were forced to delay operations time and again after discovering minor malfunctions in the spacecraft's microthrusters and observing unexpected behavior from its four gyroscopes."
Though many of the theory's underlying concepts have been tested and proven in the 89 years since Einstein first published them, the proof for two concepts has remained elusive.The engineering is awesome, but now I look forward to the results. I will certainly post here as soon as I find them.
The first concept suggests that Earth -- and almost any body in space -- creates a dimple in the universe's so-called space-time fabric. The second suggests that the rotation of the Earth twists that fabric.
Gravity Probe B will attempt to measure those effects by aligning itself with a distant star and then measuring tiny changes in the direction of its four spinning gyroscopes with respect to the line of the star. If Einstein was right, the twist in the space-time fabric should push the spinning spheres at the center of the gyroscopes ever so slightly off their axes. According to project scientists, the angle of that shift would be so small that if the spheres' axes were a kilometer long, the ends would only move by the width of a human hair.
To make measurements this small, Gravity Probe B engineers had to ensure that the spheres in each of the spacecraft's four gyroscopes would not wobble enough to ruin the measurements. To do this, they designed and developed some of the most perfect spheres ever created by humans. Composed of fused quartz, the objects the size of a Ping-Pong ball have no imperfections greater than 40 atomic layers in height. In other words, if the spheres were the size of the Earth, there would be no hills or valleys taller or deeper than 12 feet.