SpaceX is laying off about 10 percent of its workforce, a cost-cutting move the company says is required to focus on development of its next-generation launch system and a broadband satellite constellation.
"We are grateful for everything they have accomplished and their commitment to SpaceX's mission", the company continued.
In November, the company won authorisation from United States officials to put almost 12,000 satellites into orbit.
It's meant to undergo suborbital flights, with the first expected in March/April 2019, before hopefully moving on to orbital flights in 2020.
This year the company also will begin "test hops" of Starship, a prototype designed for human travel to Mars, according to the source.
The Wall Street Journal reported in December that the rocket company was planning to raise the funds at a $30.5 billion valuation.
Last week, Musk hinted that the suborbital Starship test could happen as soon as February, but some "unforeseen issues" could push it back a month.
The statement did not disclose the size of the layoffs, but a company source, speaking on background, estimated the cuts at 10 percent of the workforce.
This two-stage vehicle - composed of a Booster and a Ship - is created to eventually replace the company's Falcon 9, Falcon Heavy and the Dragon spacecraft.
SpaceX has launched 67 Falcon 9 rockets since 2010 and one Falcon Heavy, experiencing one in-flight failure in June 2015 and one on-pad explosion a year later, both tied to problems with the helium system used to pressurize the rocket's second-stage liquid oxygen propellant tank.
SpaceX makes most of its money from multibillion-dollar contracts with NASA and satellite launches.