Eight years after their Y Combinator batch, Boom successfully built and flew a supersonic jet, demonstrating the potential of hard tech startups.

Boom, a YC company, demonstrated that by assembling a team of top advisors and creating computer simulations, they could attract interest from airlines without incurring significant costs.

The XB-1 is the first independently developed supersonic jet in history, and it's a prototype for a future supersonic passenger airplane that aims to make air travel faster and more accessible.

Overture, the upcoming supersonic airliner, will carry around 65 passengers, travel at Mach 1.7, and run on 100% sustainable fuel, while also preventing sonic booms from reaching the ground, allowing it to fly over land.

In 2016, Y Combinator funded three aerospace companies, including Astranis, which have since become billion-dollar companies, showing that it's possible to succeed without a billionaire founder.

Hard Aerospace, a Y Combinator company, is working on fully electric planes, targeting regional flights which are currently losing money and are heavily subsidized by the government.

Building a supersonic jet is incredibly challenging, but it's not impossible. It requires a unique approach and a willingness to learn from mistakes along the way.

The XB-1 was built to learn all the necessary lessons for creating a supersonic jet that is safe for passengers, using technology that can be deployed on commercial airliners.

Supersonic travel will enter the market similarly to other technologies, starting at higher price points and gradually becoming more affordable, much like electric cars and smartphones.