WFIRST was designed by NASA and many astronomers to discover new planets and study dark energy (which may be the key to solving the mystery of cosmic expansion).
It is reported that WFIRST will use gravitational microlens effect to find new planets. The microlens effect is related to Einstein's relativity theory, which enables telescopes to find planets orbiting stars thousands of light years away (much farther than other planetary search technologies). But this effect only works when the gravity of a planet or star bends the light of another star, so the microlens effect of any given planet or star can be seen for several hours every millions of years. In view of this, WFIRST will continuously monitor 100 million stars in the galaxy's center over a long period of time.
It is reported that the WFIRST project began planning in May 2018 with a budget of about US$3.2 billion. Ohio State University participated in the initiation, research and design of the project.