Today, SpaceX is hoping to get back to launching — and landing — its rockets again, a little over four months after one of its Falcon 9 vehicles exploded on a Florida launchpad. The company’s vehicle is slated to take off from Vandenberg Air Force Base in California at 12:54PM ET, carrying 10 satellites into orbit for the communications company Iridium. And as is the norm with Falcon 9 launches these days, SpaceX will attempt to land the majority of the rocket upright on one of its drone ships in the Pacific Ocean following takeoff. But most of all, the launch itself needs to go smoothly if SpaceX wants to move forward and accomplish its many goals that lie ahead.

It’ll be the first flight that SpaceX has attempted since August, since the company was forced to go on a hiatus from spaceflight after the September launchpad explosion in Cape Canaveral. The vehicle was being loaded with propellant in preparation for a static fire test — a routine procedure that SpaceX does prior to flight, in which the rocket engines are turned on while the vehicle is constrained. During this fueling process, the vehicle suddenly went up in a spectacular fireball, destroying the Falcon 9 and the Israeli Amos-6 satellite that it was supposed to carry into space just a few days later.

SpaceX has spent its time grounded trying to decipher what happened, finally coming up with an official cause for the explosion two weeks ago. The source of the failure originated within the rocket’s upper liquid oxygen tank, which stores the vehicle’s super chilled liquid oxygen propellant. Also housed inside this tank are three smaller tanks called composite overwrapped pressure vessels, or COPVS. These vessels store cryogenic helium, which is needed to fill up and pressurize the liquid oxygen tank when the propellant is used up during flight. SpaceX determined that the materials making up the COPVs had a bad reaction with the liquid oxygen in the tank, ultimately causing the propellant to ignite.

With the official cause decided, SpaceX originally said it was aiming to return to flight on January 8th, but the launch was ultimately delayed until today due to rain and heavy winds this past week. The company conducted a static fire test of the Falcon 9 vehicle January 5th in preparation for the flight, and the company finally received approval from the Federal Aviation Administration to launch and land its Falcon 9 vehicle for the upcoming mission. In fact, the FAA launch license gives SpaceX permission to launch the next seven rockets for the Iridium NEXT mission — an endeavor that will put 70 satellites into orbit for Iridium.

“The FAA accepted the investigation report on the AMOS-6 mishap and has closed the investigation,” the FAA said in a statement. “SpaceX applied for a license to launch the Iridium NEXT satellites from Vandenberg Air Force Base. The FAA has granted a license for that purpose.”

The pressure is on for today’s launch, since SpaceX’s launch delays have had some important consequences. The company had to push back all of its launches last year, including the first flight of its Falcon Heavy — a larger heavy-lift vehicle that is essentially three Falcon 9 cores strapped together. SpaceX had also been planning to relaunch one of its landed rockets for the first time before the end of last year, a big milestone in its quest for reusability; that too had to be put on pause. The launch hiatus was also partially responsible for pushing one of SpaceX’s customers, Inmarsat, to book a different rocket for one of its spacecraft. Plus, an exclusive report from The Wall Street Journal reveals that SpaceX experienced a $260 million annual loss following its previous rocket explosion in 2015, as well as a 6 percent loss in revenue. So the health of the business may also be a concern following last year’s launchpad accident.

A successful launch today will be crucial for a company that has some very ambitious plans for the future. SpaceX is claiming the Falcon Heavy will finally fly this year. And with that launch, rumor is the company will attempt to land all three rocket cores after takeoff. Additionally, SpaceX has its obligations to NASA to worry about. The company has a contract to periodically send cargo to the International Space Station, and SpaceX vehicles are supposed to start sending people to the orbiting lab in 2018.

Meanwhile, SpaceX is also forging ahead — albeit slowly — with its plans to start a colony on Mars some day. Last year, CEO Elon Musk detailed the designs for the company’s future Mars colonization vehicles, and SpaceX has said that it plans to start sending spacecraft to Mars in 2018.

With such a busy manifest, the next few years could prove to be pretty wild for SpaceX. While one of the company’s launchpads at the Cape was badly damaged during the September accident, SpaceX has the option to continue launching from Vandenberg Air Force Base, as well as a newly renovated pad at Kennedy Space Center in Cape Canaveral. Those two sites will allow SpaceX to get back to its launch schedule, which includes another satellite launch later this month and a cargo resupply mission for NASA tentatively scheduled for early February.

But first, it needs to make sure today’s satellite launch goes smoothly. Up until now, weather hasn’t been that cooperative, and the mission has to deal with an instantaneous launch window. The Iridium satellites need to get into a very particular polar orbit — a path around Earth that runs from pole to pole — so there’s very little flexibility for when the Falcon 9 can get off the ground. That means there’s only one shot today to get it right.