The “new space race” that renowned entrepreneur Elon Musk called for earlier this year, is well underway, and Musk’s SpaceX is leading amid Goliath-sized incumbents, Boeing Co. (BA) and Lockheed Martin Corp. (LMT). Estimated at a value of $28 billion, SpaceX has become one of the most valuable private companies in the world, garnering funds from global investors on the basis of stunning past accomplishments and even loftier future ambitions, such as building space vessels that will be used to populate Mars. In March, Musk revealed, “We are building the first Mars or interplanetary ship right now,” according to CNBC.

Beating Boeing

SpaceX’s major competition comes in the form of United Launch Alliance, a joint venture between Boeing and Lockheed Martin. Boeing, the world’s largest aerospace company, with a market cap of $210.06 billion, is seven times larger than SpaceX, based on the $28 billion estimated valuation. Lockheed Martin is just over three times larger at a market cap of $90.56 billion.

SpaceX, with its Dragon capsules, and Boeing, with its Starliner capsules, are in direct competition with each other to fulfill contracts for NASA’s Commercial Crew program, which transports astronauts to and from the International Space Station, or ISS. But as far as building big rockets, SpaceX looks to have the upper hand, according to CNBC.

While Boeing may be NASA’s primary contractor for the new Space Launch System rocket, the first iteration of that rocket is expected to lift only slightly more weight than SpaceX’s Falcon Heavy. That launch is also not expected to happen for at least two more years after more than a decade under development.

Milestones

Falcon Heavy, launched in early February, became the most powerful commercial rocket in the world to ever be launched, capable of carrying 140,000 pounds of cargo, and which took just seven years to build. Two of the rocket’s three boosters even successfully landed back on earth, and Musk indicated that they could be reused. (See see: Elon Musk’s SpaceX to Launch World’s Most Powerful Rocket Today.)

Other SpaceX milestones include being the first in history to launch two rockets and have them land within 48 hours, as well as being the first to launch a reused rocket on a supply mission to the ISS, according to CNBC.

Lofty Ambitions

As for the future, Musk believes SpaceX will be using its rockets to complete “short trips” to Mars in 2019, with the plan of launching cargo vehicles by 2022 that would be used to bring essential supplies to build infrastructure on the Red Planet. He also plans to be rolling out a constellation of 4,425 satellites within a similar time frame. The launch of its planned satellite broadband business could push SpaceX’s valuation to $50 billion. (See see: How SpaceX Reinvented the Rocket Launch Industry).

While aiming high is important, SpaceX will need to prove at some point that its rockets are safe and reliable enough to transport humans. Despite numerous successes, there have been horrible mishaps with rockets exploding in the past, like the Falcon 9 explosion on a Florida launch pad in 2016. Musk is also often criticized for trying to do too much too fast. Despite the hype around his other company, carmaker Tesla, there are concerns the company is failing to deliver on expectations.