Why do the people who write these articles just read the headlines, look at the pretty screenshots, and start to scribble their sensationalist nonsense? Harold "Sonny" White and NASA are not building a warp drive. They are not even close.
Watch the video to see what is going on, and how far away we are. The ship design is not something NASA is building, it's a tantalizing render made by 3d artists for Harold White's program and NASA. It's important to inspire young people to study astrophysics, general relativity, et al.
What Dr. White did was to make the mathematics behind the energy requirements of the warp bubble more feasible in the real world. Originally, the warp field metric from 1994-2011 was so inefficient that it required the total negative mass-energy of a Jupiter amount. Rendering the whole prospect practically impossible - even though feasible in mathematics.
What White did, was reduce that from Jupiter amount to 1 ton of the negative energy. And no.. that is not "anti-matter", it is "negative vacuum energy", of which you can find miniscule amounts when you observe the Casimir Effect.
So now it's at least feasible both mathematically and theoretically. Though there is nothing close to the practical, which is why Harold states that he is waiting for the "Chicago Pile" moment. The first tested practical functioning of it.
We may be less than a century away, or more than 500 years away.. we simply have no way of knowing. At the moment, we have no idea how to capture, compress and harness that amount of negative vacuum energy.
What is exciting for now, is the White-Juday Interferometer, which is the only real experiment into space warp bubbles going on at our planet right now. It's an effort to warp york time (compression/expansion of space time), while a laser fires through it. Then they will look for ever so slight tiny perturbations of the laser light.
I share your excitement though. It's just important to get a reality check now and then. If you look to the bottom of the link, there is a video of Harold having a very technical talk on the warp field dynamics. The space ship designs are simply artistic renderings, made to inspire people. Maybe inspire people to study astrophysics, general relativity, etc.. so in a sense, it's still a great thing. It's very easy to get the wrong impression from a story. Put it like this.. we may be as close to warp bubble dynamics, as Leonardo Davinci was close to creating a helicopter.
NASA have been pursuing studies of faster than light travel for at least a decade now, they've had it on the backburner for specially gifted individuals like White. The great news of the improvements made on the mathematical model by White came in 2012.