In late 2010, NASA awarded contracts to three teams — Lockheed Martin, Northrop Grumman, Boeing Company — to study advanced concept designs for aircraft that could take to the skies in the year 2025.
The first one is the proposal by Boeing.
The second is the proposal by Lockheed Martin.
This one is by Northrop Grumman:
These are NASA requirements:
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.
They look 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.