Skip to main content

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

spacex ng 21 iss launch live stream unnamed 1
SpaceX

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.

What to expect from the launch

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.

Recommended Videos

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.

How to watch the launch

NASA’s Northrop Grumman 21st Cargo Resupply Services Launch

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.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
What to expect from SpaceX’s sixth megarocket test flight
SpaceX's Super Heavy launch during the fifth test flight of the Starship.

As it unleashes a record 17 million pounds of thrust at launch, the sight of SpaceX’s 120-meter-tall Starship rocket roaring skyward is something to behold.

The Elon Musk-led spaceflight company has already performed five Starship flights since the first one in April 2023, with each one more successful than the last. Comprising the upper-stage Starship spacecraft and the first-stage Super Heavy booster (collectively known as the Starship), the giant vehicle willo be used by NASA for crew and cargo missions to the moon, Mars, and possibly beyond.

Read more
SpaceX reveals date for next flight of Starship megarocket
The Starship launching from Starbase in October 2024.

SpaceX has revealed that it is targeting Monday, November 18, for the sixth test of the Starship, the world’s most powerful rocket comprising the first-stage Super Heavy booster and the upper-stage Starship spacecraft.

The massive vehicle, which creates around 17 million pounds of thrust at launch, is set to be used by NASA for crew and cargo missions to the moon, and possibly even Mars, though there’s still much testing to be done.

Read more
A SpaceX Crew Dragon is doing a shuffle at the ISS — here’s how to watch
The SpaceX Dragon spacecraft carrying NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov approaches the International Space Station as it orbits 259 miles above Oregon.

This week will see a special maneuver at the International Space Station (ISS) as a SpaceX Crew Dragon takes one of the tiniest flights ever, hopping just a few meters over from one port of the station to another. And NASA will live stream the event, so you'll be able to watch the spacecraft take this short flight as it happens.

The changeover is necessary to make space for another SpaceX craft that will arrive on Monday, October 4. But this new arrival won't carry any crew as it is a cargo craft, part of the 31st commercial resupply services mission by SpaceX. This new arrival will dock at the forward-facing port on the Space Station's Harmony module, as it is easiest for craft to dock there than on the space-facing side. But the Crew Dragon is currently occupying this port, so it needs to undock, move to the other space-facing port, and redock there.

Read more