By Timothy Milligan
On September 14, I observed the launch of the NG-23 Cygnus Resupply Mission to the International Space Station from Space Launch Complex 40. The launch vehicle was a SpaceX Falcon 9, carrying the Cygnus XL spacecraft. The mission delivered over approximately 10,828 pounds of scientific investigations, research materials and cargo to the International Space Station. On paper, it was “just” a resupply mission. In person, it was anything but.
Liftoff occurred at 6:11 p.m. (EDT), precisely on schedule. The skies around Kennedy Space Center were mostly clear, with only a few cumulus clouds in the distance. It was a beautiful Florida day, with the temperature at a comfortable 83 degrees.
This was my first time attending a Falcon 9 launch from the official NASA Press Site, which is on the Kennedy Space Center. Standing approximately 6.2 miles from the launch pad, which is actually located on the Cape Canaveral Space Force Station. I wasn’t quite sure what to expect, particularly in terms of launch trajectory and booster return.
Fortunately, the rocket’s direction was easy enough to follow visually, but the booster’s reentry burn proved harder to track. In front of me, a tracking camera, belonging to a major online platform, was already aimed at the sky. Following its guidance, I looked up just in time to see what resembled a bright firework at the zenith. A large, fiery bloom marked the Falcon 9’s reentry burn, used to slow its descent back through Earth’s atmosphere.
Moments later, a collective murmur spread through the press observers: “There it is!” The Falcon 9 booster became visible as it descended gracefully toward Landing Zone 2.
Then came the telltale sound: three sharp sonic booms echoed across the flat landscape, followed by the bright visual of the booster lowering itself behind the tree line for a precise, controlled landing.
While the visual spectacle was stunning, what stood out most was the intensity of the sonic booms, which felt louder than the initial launch sound. I heard three sonic booms in quick succession, a rapid triple report that echoed sharply across the press site. The sensation was physical as well as auditory, it felt like someone lightly pounding on your chest, each boom delivering a soft, percussive thump that you could feel. Then came the echoes off of the buildings. It felt like the sound would never stop, bouncing and rolling across the landscape. These booms were generated by different parts of the booster, typically the engine section, interstage and grid fins, as they broke the sound barrier during descent.
This observation aligns with research by Mark C. Anderson and Kent L. Gee, who found that: “For observers farther than 2 km (approximately 1.25 miles) from the launch and landing locations, the sonic boom peak overpressure exceeds the peak pressures experienced during the launch.” 1 This was certainly my experience. Although individual perception varies depending on atmospheric conditions and terrain, their data support the idea that sonic booms can register more forcefully than launch acoustics at certain distances, particularly in open areas like the NASA Press Site.
Words like “wow,” “amazing,” and “spectacular” only begin to describe how I felt witnessing this launch. The weather was perfect, the countdown proceeded without delay, and ignition occurred precisely on time. Most importantly, the launch was not “scrubbed,” a dreaded word around Kennedy Space Center.
Being at the Space Center’s press site, a place I’d only ever seen on television or online, was surreal. The nostalgia, the triumphs, the tragedies … it’s all part of the history here. I felt honored. Humbled. But I was also there to work, to cover the launch from Space Launch Complex 40.
As thrilling as it was to see the Falcon 9 lift off in person, it’s essential to remember the purpose behind it. The ISS, is only as valuable as the international crew that lives aboard it, conducting research, maintaining systems, and representing a global effort in space exploration.
Before this experience, I might have thought: “It’s only a resupply mission.” But not anymore. These missions are the lifeblood of the ISS. Without them, the station would soon become uninhabitable. Every launch is critical. Every payload matters. Every person involved is part of something extraordinary.
For more than 25 continuous years, humanity has maintained a presence on the ISS. Expedition 1, launched in 2000, began with just three crew members. As of this writing, Expedition 73 consists of 10 astronauts, a significant increase in both personnel and capability. When was the last time you had 10 people living in your house?
Thankfully, the ISS is equipped with three toilets to accommodate that many residents. 2 But life aboard the station involves more than just work, although, what a place to work. Everything we take for granted on Earth, such as breathable air, clean water and tasty food, must be transported or produced onboard. Most of these essentials are delivered via uncrewed resupply missions, including Northrop Grumman’s Cygnus, SpaceX’s Cargo Dragon, JAXA’s HTV and Russia’s Progress spacecraft.
These launches are not just about rockets; they are lifelines to the low Earth orbiting ISS. After 25 years of continuous human presence aboard the ISS, it’s easy to forget just how hard it is to keep people alive in space. It takes constant effort, vigilance, and an unwavering belief in the mission. Complacency is not an option. Not when the stakes are this high.
I grew up in the 1960s, fortunate enough to witness the live broadcast of Neil Armstrong’s first steps on the Moon, July 20, 1969. NASA has been a part of my vocabulary since I was 5 years old. So, decades later, standing at NASA’s press site to cover a space launch, I felt like I’d come full circle.
As Sgt. Joe Friday from the classic TV series Dragnet would say, “Just the facts, sir.” So here are some facts that might just baffle your mind.
All of the following figures are documented on NASA and related agency websites though the data is spread across multiple sources. 3
Total cargo flown to the ISS: 999,822.73 pounds, just shy of 1 million.
This includes consumable supplies such as air, water, food and fuel. This figure does not include six launches for which I could not find data, nor does it account for launches that failed to deliver their cargo to the ISS. It also excludes manifest items not intended to be brought inside the ISS, such as satellites and special scientific investigations.
To help visualize this: imagine a fully loaded Boeing 747 jet, complete with passengers, luggage and yes, even the kid kicking the back of your seat. That’s the scale we’re talking about.
Let’s break it down further:
• Total unmanned cargo flights: 169
• Failed missions: 5
• Fuel delivered: 126,597 pounds
• Air delivered: 8,444 pounds
• Water delivered: 58,648 pounds
• Food: Not listed separately in most sources, but rest assured, they’re not starving up there.
Let’s take a quick look at how the ISS got there. Its first component was launched by Russia. The Functional Cargo Block was deployed November 1998. 4 It took two more years of construction before the permanent habitation of the ISS started in October 2000. 5 This year we are celebrating the 25th anniversary of habitation on the ISS.
Now, for a fun visual.
Imagine you’re floating through the ISS and decide to visit the newly opened (and entirely fictional) ISS Star Hop Bar. You secure your feet in the stirrups on the floor and ask for a whiskey and Coke. The bartender smiles. You follow up with, “What’s the house wine?” Again, just a smile. Finally, you ask for something simple, just some water.
He brings you a small bag containing about 8 ounces. Then he slides you the bill.
You gasp. $680 for a bag of water? The bartender sees the look on your face. The bartender shrugs and says, “That’s our SpaceX special price. It used to be higher.”
You both laugh.
As history reminds us, spaceflight is not easy. It is dangerous. It is expensive. It can be deadly.
Spaceflight is hard. Complacency is deadly.
Two simple truths that are easy to forget when I look up at the night sky and see the International Space Station silently orbiting overhead. But its presence is no accident. The ISS was designed to pass over 90% of the world’s population a constant reminder that “We are up here.”6
So next time the ISS passes overhead, step outside, whether with a telescope, binoculars or just your own eyes, and take a moment to reflect. If you’re lucky, you might even catch it transiting the Sun or Moon.7
But remember: the ISS is more than a piece of hardware orbiting Earth. It is humanity, science, life and above all, hope, circling above the only home we have.
Timothy Milligan is a freelance reporter is an avid astrophotographer and a member of the Astronomical League and was awarded the “Imaging – Messier Observing Program” on September 12.
References:
- Acoustical Society of America, February 2025, “Why does the Falcon-9 booster make a triple sonic boom during flyback?” ↩︎
- Guinness World Records,2021, Most Toilets in a Space Station ↩︎
- Wikipedia, Uncrewed Spaceflights to the International Space Station ↩︎
- NASA, 2015, “Reference Guide to the International Space Station,” 78 ↩︎
- NASA, 2015, “Reference Guide to the International Space Station,” 89 ↩︎
- NASA, Station Facts ↩︎
- NASA, Spot the Station ↩︎
Additional Resources:
NASA Northrop Grumman CRS-23 SpaceX Falcon 9 Launch
Flyback sonic booms from Falcon-9 rockets: Measured data and some considerations for future models
NASA, Partners Adjust Next Cygnus Resupply Launch
NASA, Northrop Grumman Assessing Cygnus XL Engine Burn Plan