The phrase "trajectory into" is correct and can be used in written English
It is typically used to describe the path or direction something or someone is moving towards. Here is an example sentence: "Their ambitious plan set them on a trajectory into the world of finance and ultimately led to their success as successful business owners."
Soderblom's career has followed humankind's trajectory into the solar system.
He's taking us off our Richard Curtis trajectory into something a bit more, what – Mike Leigh?
This tidal wave is Salomon's final missive to us her expulsive, upward trajectory into a mythic, androgynous creature.
She aspires to keep dancing for years, citing Mikhail Baryshnikov's trajectory into modern dance as a model.
Her trajectory into film criticism, far from being impeded by her religious vocation, was propelled by it.
The battalion -- including insurance agents, checkout clerks, sales people and others -- ultimately would follow a grim trajectory into the episodes of prisoner abuse that have shocked the nation.
And indeed, the creation of one such series – a Simpsons-like animation called Figland – is the centrepiece of Wolitzer's story of the group's trajectory into adulthood.
Some leather-bound notebooks contained decades-old clippings of Truffino's Mosquito Coast-esque trajectory into this jungle after leaving post-war Europe.
Lou Anna K. Simon, the president of Michigan State, said the university wanted "to symbolize our trajectory into the future, because of the nature of the architecture and the architect we selected".
He dropped out, "sadly", he says, although he believes that, even for a short time, college served a purpose, giving him a breather from a too-fast trajectory into working life.
Even those who view her trajectory into fame as a symptom of everything that's wrong with the world today and those who assume she is stupid, who claim some kind of moral or intellectual superiority, keep talking about her.
