Before it embarks on all of that, however, it first has to launch what would normally be a routine flight of commercial satellites to orbit. But that launch, scheduled for Monday, is now anything but routine — and is instead one of the most important in history of the company.

The launch from Vandenberg Air Force Base is the first since SpaceX’s rocket exploded on Sept. 1 while being fueled ahead of an engine test fire. That explosion was the company’s second failure in less than two years — in 2015, it lost a rocket a couple minutes into flight — leading to questions about its ability to fly reliably.

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In addition to the goals of Mars and resuming the nation's manned spaceflight program, the company also has a massive backlog of launches that was delayed while the company was grounded during its four-month investigation.

The stakes for this flight, then, are huge, said Todd Harrison, the director of the Aerospace Security Project at the Center for Strategic and International Studies.

“They’ve got to prove it and restore confidence in their system on this flight,” he said. “If they have another failure, it’s going to stop them dead in their tracks.”

On Friday, the Federal Aviation Administration cleared the way for SpaceX’s launch. The agency accepted SpaceX’s investigative report on its rocket explosion, closing the case, and issued it a launch license.

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On Thursday, Musk tweeted that SpaceX successfully performed an engine test firing and wrote that, “All systems are go for launch next week.” Originally, the launch was scheduled for Sunday, and it was unclear why the schedule slipped a day to Monday.

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Earlier this week, the company said the cause of the September explosion was traced to a problem with a pressure vessel in the second-stage liquid oxygen tank. The tank buckled, the company said, and supercooled liquid oxygen pooled in the lining. The fuel was ignited by breaking fibers or friction.

SpaceX said in the short term, it plans to change the way it loads fuel. Eventually, it plans to change the design of the pressure vessels to prevent buckling.

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Every launch carries the risk of failure, said Jim Muncy, the president of PoliSpace, a consulting firm. SpaceX’s Falcon 9 is a “proven vehicle,” he said. SpaceX continually tries to innovate, and had been super cooling its fuel to make it more dense so that the rocket could carry more of it.

The extra fuel was necessary as the company began flying its rocket boosters back to land — or to ships at sea — so that they could be reused. But taking such advanced steps — no one had ever successfully landed an orbital-class rocket before — can cause problems, Muncy said.

“As you try to increase performance, you find out if you’re pushing the envelope too far,” he said. “They’re clearly pulling back and not pushing the envelope as much with this launch.”