How to watch today’s SpaceX launch — and why it matters

Today SpaceX will launch a Falcon 9 rocket, for the first time since the September 1^st accident that destroyed another vehicle during a test firing. After months of investigation, SpaceX finally said it had found the cause of that accident earlier this month, and was then given permission to resume launches.

The launch, at California’s Vandenburg Air Force Base, is expected at 12:54 p.m. EST, and SpaceX will stream it live here starting a little before that.

The rocket’s payload will be 10 satellites to be deployed for the communications firm Iridium. But there will be a lot more riding on the launch than that—the future of the company, and, without too much hyperbole, the human race.

Here’s why. Obviously, halting services for more than four months is no good for any business. A report Friday from the Wall Street Journal claimed that a previous accident and fleet grounding in 2015 led to a quarter-billion dollar annual loss that year.

The numbers for 2016 are probably just as bad, since, according to the Journal, the September accident pushed half of the company’s planned 2016 launches off its schedule. SpaceX has removed claims that it is “profitable and cash-flow positive” from its website.

SpaceX officials told the Journal that the company has more than $1 billion cash on hand and no debt, as well as a long line of customers waiting for future launches.

But we’ve already seen that accidents can push away customers. Britain’s Inmarsat pulled one launch order in early December. Inmarsat officials said it was more an issue of scheduling than any mistrust of SpaceX’s reliability, though, and the company still has another launch order with SpaceX for the middle of this year.

The September accident also put the brakes on one of SpaceX’s most important long-term strategic goals—proving that it can re-use its rockets. The first launch of a recovered rocket booster was previously scheduled for late 2016, but that never happened. SpaceX has to get re-using rockets back on the agenda soon—while its launches are already a bargain compared to competing space services’, reusing its rockets would push those prices down even further, giving it a massive edge for the long term.

Any signs of trouble today, then, would have huge consequences both for the company’s fundamentals, and the feasibility of Elon Musk’s most aggressive goal—colonizing Mars. Musk wants to get humans to the Red Planet by 2024, and to do that, the company needs to generate consistent profits to fund development of its next generation of rockets.

Another revelation from WSJ’s Friday report was that even winning the satellite-launch market might not be enough. The company plans to derive a much more of its future revenue—and, in turn, development funds—from a satellite internet service.

But reliable, affordable rockets would still be the company’s most fundamental asset. Today’s launch has to prove SpaceX can provide them.

This story originally appeared on Fortune.com. Copyright 2017