This is the first time the company has had two capsules in orbit at the same time, the other one delivered four astronauts to the station in November.
‘Dragons everywhere you look,’ Kenny Todd, Nasa’s deputy space station program manager, said.
This was a milestone mission for SpaceX – marking the 21st cargo mission for NASA, the 24th launch of the year and 100 successful Falcon 9 rocket launches.
Launching from NASA’s Kennedy Space Center in Florida on Sunday, the newer, bigger version of the Dragon supply ship will dock with the ISS at 18:30 GMT today.
With NASA’s commercial crew program officially underway, SpaceX expects to always have at least one Dragon capsule at the space station.
SpaceX’s Falcon 9 rocket blasted off with the latest Dragon at 16:17 GMT on Sunday, where coronavirus precautions kept staff to a minimum.
The first-stage booster was making its fourth flight and landed on one of SpaceX’s drone ships in the Atlantic Ocean – called ‘Of Course I still Love You’ – several minutes after the take-off, leaving it open for another flight in the future.
The same booster also launched NASA astronauts to the ISS in the summer, a communications satellite for the South Korean military and missions for SpaceX.
The new version of the Dragon supply capsule is about the same size as the crew Dragon capsule – and will reach the ISS at 18:30 GMT on Monday.
As well as an array of Christmas presents and personal items, the 6,400lb shipment includes billions of microbes and crushed asteroid samples for a biomining study.
Also on their way to the orbiting laboratory are a new medical device to provide rapid blood test results for astronauts in space, and a privately owned and operated chamber to move experiments as big as refrigerators outside the orbiting lab.
Forty mice are also flying for bone and eye studies, two areas of weakness for astronauts during long space stays.
This is the first time the company has had two capsules in orbit at the same time, the other one delivered four astronauts to the station in November – the first stage of the Falcon 9 rocket used on this flight was also launched to send astronauts to the ISS in the summer
The first-stage booster – that lifted the capsule into orbit – was making its fourth flight and landed on one of SpaceX’s drone ships in the Atlantic Ocean – called ‘Of Course I still Love You’ – several minutes after the take-off, leaving it open for another flight in the future
Mr Todd said all this research was ‘the ultimate Christmas present’ for astronaut Kate Rubins, a virus hunter who performed the first DNA sequencing in space.
As for more personal presents for the four Americans, two Russians and one Japanese on board, Mr Todd said last week: ‘I don’t like to get out in front of Santa Claus. I fear it might mess up my own Christmas.
‘Let’s see what happens when they open the hatch … I’m optimistic.’
For the astronauts’ Christmas feast, the Dragon is carrying roast turkey, cornbread dressing, cranberry sauce, shortbread biscuits and tubes of icing.
The first-stage booster successfully landed on a SpaceX platform and will likely be used again in a future mission for the firm
The capsule will remain at the space station for about a month before undocking with experiments and old equipment, and splashing into the Atlantic in January. Onlookers watched as it launched for the ISS on Sunday
This is SpaceX’s 21st station supply run for NASA since 2012. The flight was delayed a day by rough weather in the booster-recovery area offshore
The station crew watched a live broadcast of the launch, from 250 miles (400km) above Earth.
This updated cargo-carrying model is as large as the SpaceX crew capsule and will dock to the orbiting lab by itself.
Previous SpaceX cargo ships needed the station’s robot arm for anchoring.
The capsule will remain at the space station for about a month before undocking with experiments and old equipment, and splashing into the Atlantic in January.
That’s another change from SpaceX’s older cargo ships, which parachuted into the Pacific. Returning closer to Cape Canaveral will save recycling time.
This is SpaceX’s 21st station supply run for NASA since 2012. The flight was delayed a day by rough weather in the booster-recovery area offshore.
EXPLAINED: THE $100 BILLION INTERNATIONAL SPACE STATION SITS 250 MILES ABOVE THE EARTH
The International Space Station (ISS) is a $100 billion (£80 billion) science and engineering laboratory that orbits 250 miles (400 km) above Earth.
It has been permanently staffed by rotating crews of astronauts and cosmonauts since November 2000.
Research conducted aboard the ISS often requires one or more of the unusual conditions present in low Earth orbit, such as low-gravity or oxygen.
ISS studies have investigated human research, space medicine, life sciences, physical sciences, astronomy and meteorology.
The US space agency, Nasa, spends about $3 billion (£2.4 billion) a year on the space station program, a level of funding that is endorsed by the Trump administration and Congress.
A U.S. House of Representatives committee that oversees Nasa has begun looking at whether to extend the program beyond 2024.
Alternatively the money could be used to speed up planned human space initiatives to the moon and Mars.