Rocket builder ABL Space on Monday announced the close of a $200 million round of funding from existing investors, bumping the private company’s valuation up to $2.4 billion.

ABL’s latest financing is an expansion of the round raised in March, the company said. The funds came from existing investors, which include T. Rowe Price, Fidelity Management, Venrock, New Science Ventures, Lynett Capital, and Lockheed Martin Ventures. The company has raised $420 million to date.

ABL said it plans to use the new funds to scale production of its RS1 rockets and “conduct research and development of future systems.”

The company aims to launch its first RS1 rocket from Alaska before the end of this year, ABL president Dan Piemont told CNBC in September.

ABL is developing its line of RS1 rockets, which stand 88 feet tall and are designed to launch as many as 1,350 kilograms (nearly 1½ tons) of payload to low Earth orbit. The price of each launch is $12 million.

The price puts RS1 in the middle of the commercial launch market. Rocket Lab’s smaller Electron costs $7 million per launch and SpaceX’s heavier Falcon 9 costs $62 million.

The company noted that its manifest features 14 customers and a backlog of 75 contracted launches. That includes a bulk order from Lockheed Martin earlier this year. The company signed a long-term agreement with ABL for up to 58 rockets for launches through 2029.