JARDABEREZA: not really
In fact, it’s illegal for SpaceX to discriminate against non-US citizens if they are otherwise allowed to work in the US, except to the extent they are following the requirements of another law.
ITAR and the EAR do prevent SpaceX from showing controlled technology to someone who is not a “US Person.” However, the definition of “US Person” includes US citizens, green card holders, and persons allowed to work in the US as asylees or refugees. Therefore, SpaceX can hire anyone (so long as they are allowed to work in the US) for jobs that don’t require access to export-controlled technology.
For jobs that do require access to export-controlled technology, SpaceX can hire “US Persons,” which includes categories of people who are not US citizens. If SpaceX wants to hire someone who isn’t a US Person, the ITAR and EAR still don’t necessarily prevent SpaceX from hiring such persons; rather, they require SpaceX to first ask the government for permission (often in the form of a technical assistance agreement or license) before transferring controlled information to that person.
Finally, if there is a particular job that requires an employee to have access to classified data (such as top secret) that belongs to the government, then this job might require a US citizen. Most jobs at SpaceX wouldn’t require such access. -
https://www.quora.com/Why-does-SpaceX-not-hire-non-US-citizens-even-if-Elon-Musk-himself-is-non-American-but-a-South-African-citizen-What-about-ITAR-effects-this-and-why