SpaceX doubleheader! Watch 2 Falcon 9 rockets lift off from Florida Sunday – Space.com

CAPE CANAVERAL, Fla. — SpaceX is preparing for a potential launch doubleheader on Sunday (Aug. 30), and you can watch the action live online.  

On Sunday morning, the company’s Starlink internet megaconstellation is expected to grow as SpaceX plans to launch an additional 60 satellites into orbit atop a Falcon 9 rocket. Just nine hours later, a different Falcon 9 is slated to deliver the Argentinian satellite SAOCOM-1B into a polar orbit, marking the first such mission to fly from the Cape since the 1960s. 

The Starlink mission is scheduled to launch from Pad 39A at NASA’s Kennedy Space Center at 10:12 a.m. EDT (1412 GMT). SAOCOM-1B will fly from SpaceX’s other Florida launch pad, at Space Launch Complex-40 at Cape Canaveral Space Force Station. That liftoff is scheduled for 7:18 p.m. EDT (2318 GMT). 

You can watch both launches live here at Space.com and on our homepage, courtesy of SpaceX, beginning about 15 minutes before liftoff. You’ll also be able to watch the launches directly from SpaceX

Related: SpaceX’s Starlink satellite megaconstellation launches in photos

The launch doubleheader is contingent upon a couple of factors. First, the weather needs to cooperate, and summertime in Florida can be tricky. The most recent weather reports issued by the Air Force’s 45th Weather Squadron do not look terribly promising, with a 50% chance of favorable conditions for Starlink and only a 40% chance of favorable conditions for SAOCOM-1B. 

SpaceX also needs to get launch approvals from the Eastern Range, the entity that oversees all launch operations on the East Coast. The company announced potential launch times on Friday (Aug. 28), but those assumed that United Launch Alliance’s (ULA) Delta IV Heavy rocket would launch early Saturday morning (Aug. 29) from Cape Canaveral, which did not happen.  

The Delta IV Heavy’s engines ignited and its on board computers quickly shut them down after detecting an anomaly. ULA has not yet announced what caused the shutdown but has said it will be at least a week before its triple-barrel rocket will attempt to fly again. 

The Delta IV Heavy launch directly affects SpaceX’s plans because it will deliver a national security payload. The satellite perched atop the massive rocket is a payload for the National Reconnaissance Office (NRO), the U.S. government’s spy satellite agency. There’s a hierarchy when it comes to launch payloads, with NRO satellites receiving priority over all other missions, followed by civilian (such as NASA) and then finally commercial payloads.  

SAOCOM-1B will be the first satellite launched into a polar-orbiting trajectory from Cape Canaveral since the 1960s. Typically, polar-orbiting missions are launched from the West Coast, at Vandenberg Air Force Base in California. That’s because they can fly north or south over open water, which is not the case in Florida.  

Most launches from Florida blast off on an easterly trek, while polar launches need to go north or south. In late 1960, debris from a Thor rocket reportedly fell on Cuba and killed a cow. This incident resulted in polar launches being moved to California. 

Officials were later able to secure the rights to launch this type of mission from Florida, but only if the rocket had an automated flight termination system, which the Falcon 9 does. For the SAOCOM-1B mission, the Air Force secured a southerly corridor that passes over Cuba, while the rocket’s first stage will return to land and touch down at SpaceX’s Landing Zone 1 at Cape Canaveral. 

There is some concern that the SAOCOM-1B mission’s unique flight path puts Space Launch Complex 37 (and the Delta IV Heavy) in the hazard zone. Since ULA was unable to get the Heavy off the ground Saturday morning, there was some speculation that the SAOCOM-1B mission would have to stand down until further notice. However, SpaceX’s communications team tweeted that, as of Saturday afternoon, both missions were still on for Sunday.   

Related: Why SpaceX’s Starlink satellites caught astronomers off guard

SpaceX hopes to provide global broadband coverage with its Starlink megaconstellation. Users on the ground will employ a small terminal (no larger than a laptop) to connect to the ever-growing constellation flying overhead. 

To date, SpaceX has launched more than 600 of the internet-beaming satellites. Company founder and CEO Elon Musk has said that there need to be between 500 and 800 satellites in orbit before service can begin to roll out. Users are beta-testing the service now, but many more satellites may end up launching before Musk and SpaceX connect the world. 

The weather on Sunday morning looks iffy, with only a 50% chance of favorable weather for Starlink, according to forecasters at the 45th Weather Squadron. Temperatures in the area are supposed to be around 83 degrees Fahrenheit (28 degrees Celsius) with some thick clouds being the main cause for concern. 

Later in the day, the weather conditions deteriorate a bit with just a 40% chance of launch for SAOCOM-1B. Temperatures in the area should stay around 83 degrees Fahrenheit, but forecasters are concerned about the potential for storm clouds to develop.

SpaceX has deployed one of its two drone ships, Of Course I Still Love You, to the designated recovery zone in the Atlantic Ocean. Here the massive ship will wait for the Starlink Falcon 9’s first-stage booster to return to Earth. The first stage used in the SAOCOM-1B mission will land on terra firma at Cape Canaveral Air Force station, and locals should be treated to some sonic booms. 

SpaceX is also expected to attempt to recover the Falcon 9 payload fairings, or nose cones, as the company deployed its two net-equipped boats to different locations. One ship will be stationed in the Atlantic Ocean at each recovery zone to support the recovery efforts of both missions. 

Follow Amy Thompson on Twitter @astrogingersnap. Follow us on Twitter @Spacedotcom or Facebook.