This weekend, SpaceX made a few updates to its website, changing the launch capabilities of its Falcon rockets. The company claims its Falcon 9 rocket can transport nearly twice as much weight into lower Earth orbit as originally listed. The upcoming Falcon Heavy — a much bigger version of the Falcon 9 that's currently in development — will be able to carry even more than the company said previously.

The biggest change was in regards to the Falcon 9. Originally, SpaceX listed the rocket as being able to launch close to 29,000 pounds into lower Earth orbit. Now, the Falcon 9 can launch more than 50,000 pounds to LEO, according to SpaceX. The company also claims the Falcon 9 can get a payload weighing 8,860 pounds to Mars. CEO Elon Musk indicated on Twitter that SpaceX didn't make any physical changes to the rocket's engines, but testing revealed the vehicle was even more robust.

@lukealization No physical changes to the engine. This thrust increase is based on delta qual tests. It is just tougher than we thought. — Elon Musk (@elonmusk) April 30, 2016

Musk also noted that these max payload capacities refer to the expendable versions of its rockets. Those are the rockets that don't land after launch. He said the reusable rockets will be 30 to 40 percent less capable than the expendable versions, presumably due to fuel constraints.

@elonmusk Max performance numbers are for expendable launches. Subtract 30% to 40% for reusable booster payload. — Elon Musk (@elonmusk) April 30, 2016

The company also updated the launch capabilities of the Falcon Heavy, claiming the giant rocket can get even more weight into lower Earth orbit and on to Mars than before. The Falcon Heavy has yet to fly, though. SpaceX says the rocket's first flight will happen sometime in November 2016, but the rocket's debut has been pushed back a few times before.

The Falcon Heavy's performance capabilities will be crucial to SpaceX's plans to send spacecraft to Mars in 2018. The company announced this past week that it wants to send its Dragon cargo capsule to the Red Planet, to test out ways to land heavy payloads there. In order to start a Martian colony — SpaceX's long-term goal — the company is going to need to put a lot of hardware and supplies on Mars first. That means the Falcon Heavy will need to be able to transport a lot of weight into deep space.

Update May 1st, 3:31PM ET: The article was updated to include an additional Musk tweet about max performance numbers.

SpaceX is sending spacecraft to Mars in 2018