Because Scientific Method Demands It
Topic: Science
Einstein could have been wrong.

It's not likely, but according to the scientific method, any theory has to be tested and those test results are not valid unless they can be reproduced.

So when Einstein predicted that gravity wells can not just attract, but actually bend space around them, it seemed pretty weird, but he had the math to back it up. The problem with math is that it's not really observable. Even basing matter's behaviour on a graphics display from a computer program is just a model. And it doesn't even have true gravity; just a model based on what little is understood of it. Scientific method demands true observation, not a best guess based on a model of a best guess.

So to that end, scientists are launching gravity probes to test this theory. Essentially, these extremely delicate and sensitive instruments will obtain positions 400 miles above the north and south poles, enabling them to be a near perfect space/time reference.

The point here is to examine how a gravity well affects reality, and to what degree. It's not just to prove Einstein was right (or wrong). The real knowledge gained from this will give insight to how the universe works on a quantum level, and on a planetary level.

So many concepts of space-time depend on these theories. No matter what the probes read, the waterfall of data will be very far-reaching. Every theory that depends upon the space-time predictions of Einstein will be affected.

If you're interested in this sort of thing at all, I urge you to read the web site linked up there. If you're not, I'm shocked. True, it won't change your paycheck, your job, or get you a date. But it will help science learn how our universe works, and help mankind understand reality itself. That's pretty exciting to me.