Elon Musk-led SpaceX has raised $100 million by selling shares, in an extension to a financing round earlier this year that raised up to $350 million, a regulatory filing showed on Monday.

SpaceX’s funding round in July had valued the rocket maker at about $21 billion, according to news reports.

In May, Space Exploration Technologies launched its first satellite for the US military with its Falcon 9 rocket, breaking a 10-year monopoly held by a partnership of Lockheed Martin and Boeing.

The Hawthorne, California-based company also has also outlined plans for a trip to Mars in 2022, to be followed by a manned mission to the red planet by 2024.

Besides SpaceX, Musk also leads electric car maker Tesla.