Skip to main content
  1. Home
  2. Space
  3. News

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

Add as a preferred source on Google
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…
NASA built the Roman Space Telescope to study dark matter, but it can also help protect Earth from killer asteroids
The Nancy Grace Roman Space Telescope wasn't built to hunt asteroids, but it turns out to be great at it.
Nancy Grace Roman space telescope.

NASA is about to launch a telescope built to unlock some of the universe's biggest mysteries, and it turns out that same design could help protect Earth along the way.

The Nancy Grace Roman Space Telescope is set to launch from Kennedy Space Center on August 30, 2026, with a primary mission focused on studying dark matter and dark energy - the invisible forces shaping galaxies and cosmic expansion. Researchers now say its unique design also makes it unexpectedly effective at spotting dangerous asteroids headed our way (via MIT Technology Review).

Read more
Space is becoming Bezos and Musk’s next data center site, and we have every reason to worry
The AI boom is coming for the night sky
How Vast's space station will look in orbit.

AI data centers already consume vast amounts of electricity and water on Earth, so Silicon Valley has begun looking somewhere considerably more spacious... literally.

Elon Musk's SpaceX and Jeff Bezos' Blue Origin, along with several other companies, have proposed enormous constellations of satellites designed to operate as orbital data centers. However, environmental groups and former space officials are now warning that putting them into orbit at the proposed scale could have severe consequences for Earth's atmosphere and the night sky.

Read more
The first possible exomoon is here, and it makes our Moon look hilariously tiny
Scientists may have found the first exomoon, except this one is the size of Jupiter
This artist’s concept depicts a potential volcanic moon between the exoplanet WASP-49 b, left, and its parent star. New evidence indicating that a massive sodium cloud observed near WASP-49 b is produced by neither the planet nor the star has prompted researchers to ask if its origin could be an exomoon.

We have already discovered more than 6,000 planets outside of our immediate neighborhood. Yet, finding a moon orbiting one of those distant worlds has proved considerably harder. Astronomers may finally have something close to the real deal, but this particular object stretches the word “moon” almost beyond recognition.

Using the European Southern Observatory’s Very Large Telescope in Chile, researchers detected strong evidence for a moon-like object in the CD-35 2722 system. Further observations are still necessary to confirm the discovery, but it could become the first confidently detected natural satellite outside our solar system. There is still one tiny complication though. This moon is apparently massive.

Read more