Why SpaceX is delivering a penny, a hexnut, and two balloons to the ISS on Saturday

By Georgina Torbet Published August 2, 2024

On Saturday, NASA is working with SpaceX and Northrop Grumman to launch a resupply mission to the International Space Station. Loaded up with cargo and scientific experiments, the NG-21 mission will launch from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida, and the launch of the uncrewed mission will be live-streamed so you can watch at home.

The mission will use a SpaceX Falcon 9 rocket and a Northrop Grumman Cygnus spacecraft that will be filled with more than 8,200 pounds of supplies. That includes a range of science experiments, including testing part of a water recovery system, an investigation into how to produce stem cells in microgravity, and studies on how the DNA of microorganisms is affected by spaceflight.

The water recovery test uses beads packed close together to understand how filtration systems respond to microgravity, by looking at how both gas and liquid moves simultaneously through porous material. The design of the system could be used for water filtration systems on the moon or Mars, and could also be used on Earth for water purification or for heating and cooling systems.

Other experiments onboard include a demonstration to be recorded for the public under the STEMonstration series. Astronauts will use a penny, a hexnut, and two clear balloons to demonstrate the principles of centripetal force and to show how microgravity affects sounds by whirling each object inside an inflated balloon.

Also included in the Cygnus are 2,251 pounds of supplies for the crew, plus spacewalk equipment, vehicle hardware, and computer resources.

The spacecraft is scheduled to arrive at the ISS on Monday, August 5, where it will dock with the station’s Unity module, and will spend six months connected to the station. Its departure is scheduled for January 2025.

The launch is scheduled for 11:29 a.m. ET (8:29 a.m. PT) on Saturday, August 3. The launch will be live-streamed by NASA and by SpaceX, showing the liftoff of the mission and the beginning of the craft’s journey to the International Space Station.

Coverage begins at 11:10 a.m. ET (8:10 a.m. PT), and you can watch via the NASA+ app or by heading to SpaceX’s website. But the easiest way to watch is via YouTube, which you can access using the video embedded above, or by heading to NASA’s YouTube page for the event.