Space.com reported that SpaceX successfully launched its 21st rocket of 2021. The SpaceX Dragon sent a robotic cargo capsule to the International Space Station (ISS) before nailing a perfect landing at sea. 

A two-stage Falcon 9 rocket blasted off from NASA's Kennedy Space Center on Sunday. Its mission is to resupply the ISS. This is the 24th supply mission to the permanent orbiting lab.

"That is the 90th successful landing of an orbital class rocket and the very first for our newest drone ship, 'A Shortfall of Gravitas,'" Andy Tran of SpaceX said during a webcast of the launch. "What a great way to start today's mission."

After the liftoff, the first-stage Falcon 9 returned to Earth. And it had a perfect landing on one of SpaceX's drone ships in the Atlantic Ocean.

The massive ship, named "A Shortfall of Gravitas," is the newest of SpaceX’s three drone ships. It was built as a recovery vessel that catches falling boosters and returns them to port. The boosters are recycled for later reuse. Elon Musk's SpaceX developed the concept of recycling rockets.

The first-stage booster B1061 has been used three times. And the launcher now has four missions under its belt. 

The landing in the Atlantic marks the 90th recovery of a Falcon first stage. SpaceX developed the recovery process with its first booster in 2015.

The CRS-23 cargo mission was delayed for 24 hours due to poor weather at the launch site. Space Force’s 45th Weather Squadron warned of the weather caused by Hurricane Ida’s direct hit one state over in Louisiana.

The robotic SpaceX Dragon was seen Monday morning by the astronauts at the station. And astronaut Shane Kimbrough tweeted out images of its approach.

SpaceX Dragon packed with supplies

Onboard is more than 4,800 pounds (2,200 kilograms) of supplies. And also lots of scientific experiments and hardware will be “unpacked” at the ISS. This is including a new robotic arm for testing in the Bishop Airlock.

As part of a technology demonstration, the robotic arm will flip switches and push buttons in an attempt to prove it has what it takes to carry out routine astronaut tasks.

Launch details

The latest SpaceX vehicle joins the Crew Dragon "Endeavour," which launched on April 23. It arrived at the ISS carrying a crew of four US astronauts. It is not unusual to have multiple vehicles at the space lab. 

So far every day this year at least one Dragon remains parked at the space station. And sometimes there are two Dragons docked there.

In addition to all the experiment supplies Joel Montalbano, ISS program manager for NASA, says the crew will also be receiving lots of special treats. 

"We're sending up a good amount of fruit," he said during a pre-launch news conference on Friday. "We have lemons, onions, some avocados, some cherry tomatoes, and also some ice cream. That's a big hit with our crew."

So far this has been a busy summer at the ISS. The crew has received and installed new solar arrays. And the Russian science module,  Nauka threw the space station off-kilter, before it successfully docked.

"Working with SpaceX and working with our other commercial providers has been just an outstanding partnership that we've established between NASA and the commercial industry," Montalbano added. "We are excited to launch this mission and get this incredible science to the station."

In the meantime, SpaceX is continuing work on its skyscraper rocket.