In that movie, while attempting to evade the Empire and go through the Kessel Run as fast as possible in order to reach Savareen before all the coaxium they have explodes, Lando Calrissian downloads 元-37's navigational system into the Millennium Falcon.

What Lucas is referring to in The Making of Star Wars wasn't shown on-screen until Solo: A Star Wars Story in 2018. Rinzler's The Making of Star Wars, Lucas noted that Han Solo modified the Millennium Falcon so that he could travel the shortest possible distances. Once A New Hope was in theaters, Lucas began ironing out the rest of the Star Wars franchise over the summer in 1977 - and that meant discussing seemingly minuscule details that would later become bigger issues, such as Han Solo's use of the word 'parsec' when referring to the Millennium Falcon. Related: George Lucas Explained Why Chewbacca Didn't Get A Medal In 1977 So how could someone calculate a record in speed by using a measurement of distance? This is a question the Star Wars franchise struggled with for years, and it was one that Lucas actually tried to answer right not long after A New Hope had released.

In Star Wars, as well as real-life, a parsec is a measurement of distance equal to about 19 trillion miles (3.26 light years). But the problem was that Han Solo's Kessel Run record - not to mention the fact that he referred to a parsec as a measurement of time - didn't make sense.

Whats a parsec star wars