In late 2010, NASA awarded contracts to three teams -- Lockheed Martin, Northrop Grumman, The Boeing Company -- to study advanced concept designs for aircraft that could take to the skies in the year 2025.
At the time of the award, the team gave NASA a sneak peek of the particular design they plan to pursue.
Each design looks very different, but all final designs have to meet NASA's goals for less noise, cleaner exhaust and lower fuel consumption. Each aircraft has to be able to do all of those things at the same time, which requires a complex dance of tradeoffs between all of the new advanced technologies that will be on these vehicles.
The proposed aircraft will also have to operate safely in a more modernized air traffic management system.
And each design has to fly up to 85 percent of the speed of sound; cover a range of approximately 7,000 miles; and carry between 50,000 and 100,000 pounds of payload, either passengers or cargo.
For the rest of this year, each team will be exploring, testing, simulating, keeping and discarding innovations and technologies to make their design a winner.
How different will the final designs look from these initial glimpses?