SpaceX to return NASA astronauts to Earth for the 1st time today. You can watch it live.

Update for 4 p.m. EDT: SpaceX's Demo-2 Crew Dragon spacecraft successfully splashed down off the Pensacola, Florida coast in the Gulf of Mexico at 2:48 p.m. EDT (1848 GMT). Read our full story here. NASA will hold a briefing no earlier than 4:45 p.m. EDT (2045 GMT).

It's splashdown day for SpaceX's first NASA crew. 

After a two-month trip to International Space Station, the SpaceX Crew Dragon Endeavour carrying NASA astronauts Bob Behnken and Doug Hurley will return to Earth today (Aug. 2). The splashdown is set for 2:48 p.m. EDT (1948 GMT) off the coast of Pensacola, Florida in the Gulf of Mexico. It will mark the first water landing since 1975, when the NASA astronauts on the joint Apollo-Soyuz test mission returned home. 

You can watch that splashdown live here and on Space.com's homepage, courtesy of NASA TV. NASA is providing continuous coverage of the landing.

Video: SpaceX Demo-2's Crew Dragon undocks from space station
Full coverage: SpaceX's historic Demo-2 Crew Dragon astronaut test flight

All eyes may be on Crew Dragon and the weather, but two boys are also eagerly awaiting the return of their dads. Behnken's son Theo, age 6, and Hurley's son Jack, 10, woke their space dads today with an adorable wake up call from Earth.

"Good morning, Dragon Endeavour," said Jack in the wake up call at 7:40 a.m. EDT (1140 GMT). "I'm happy you went into space, but I'm even happier that you're coming back home."  

"Wake up! Wake up! Wake up! Wake up. Hey, Wake Up!" Theo added. "Don't worry you can sleep in tomorrow. Hurry home so we can go get my dog!"

The astronauts welcomed the surprise call from their sons.  The astronauts are returning a toy dinosaur, Tremor the Apatasaurus, to Earth for their boys. They used it as a zero-g indicator for their flight.

"Thank you especially to Jack and to Theo for that wake up call," Behnken radioed SpaceX's mission control center in Hawthorne, California. "Hopefully the pressure's all on whoever is making the weather call because those boys seem excited to bring us home." 

The weather has been a key question for today's splashdown. NASA and SpaceX had seven different splashdown sites, four in the Gulf of Mexico and three in on Florida's east coast, to choose from for today's return. They opted for a site offshore of Pensacola where the weather effects from Tropical Storm Isaias are expected to be low. Another site off the coast of Panama City is the backup. 

Related: How NASA's Demo-2 astronauts will make a historic splashdown

Behnken and Hurley are wrapping up SpaceX's Demo-2 test flight for NASA to prove that the company's Crew Dragon space capsules are ready to begin operational crew flights to the International Space Station. The mission launched on a SpaceX Falcon 9 rocket May 30 and arrived at the station a day later, marking the first orbital flight of American astronauts from U.S. soil since NASA's space shuttles retired in 2011.

Endeavour (Behnken and Hurley picked the capsule's name) undocked from the space station Saturday (Aug.1) to begin the 19-hour trip home after 63 days at the orbiting lab. The astronauts are bringing home 330 lbs. (150 kilograms) of science experiments and other cargo from the station. They're also bringing home an American flag left behind in 2011 by NASA's last shuttle crew that will ultimately fly to the moon with the agency's Artemis program. 

"We're very proud to return this flag home and see what's next for it on its journey to the moon," Hurley told reporters Friday (July 31) before leaving the space station.

SpaceX is one of two companies with NASA contracts to fly astronauts to and from the station. The other company, Boeing, will use its own Starliner capsules and Atlas V rockets to make those flights. 

So far, SpaceX's Demo-2 test flight for NASA has gone swimmingly. The spacecraft has passed all of its tests in orbit, with today's reentry and splashdown as its final trial. 

Splashdown activities begin in earnest at 1:51 p.m. EDT (1751 GMT), when Crew Dragon will jettison its cylindrical service module, called a "trunk," to prepare for reentry. Five minutes later, at 1:56 p.m. ET (1756 GMT), the spacecraft will perform a deorbit burn to put it on course for entry and landing. 

The capsule will slam into the Earth's atmosphere at hypersonic speeds, flying at about 17,500 mph (28,200 kmh), relying on its heat shield to slow the craft to about 350 mph (560 km/h) as it protects Behnken and Hurley from the super-hot temperatures of reentry.  The capsule will then deploy its parachutes to slow it to about 15 mph (24 km/h) for splashdown. On Earth, SpaceX has a recovery ship waiting to retrieve Crew Dragon from the ocean within an hour after splashdown. 

"We've had pretty good luck with Endeavour with regards to on-orbit test," Hurley told reporters Friday. "So we expect nothing different for the splashdown."

Visit Space.com today for complete coverage of SpaceX's Demo-2 Crew Dragon splashdown.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik. Follow us @Spacedotcom, Facebook and Instagram.