The Reduced Gravity Office at the Johnson Space Center in Houston is home to NASA’s own flying, microgravity laboratory, “The Weightless Wonder.” It’s every bit as incredible as the name suggests.
It started when Gizmodo got a call from Zach Barbeau, an engineering undergrad at Oklahoma State University. His team had been selected — with a handful of others from different colleges and universities — to fly their proposed experiments onboard NASA’s famous zero gravity plane. They were allowed to invite one reporter. Did I want to go?
Did I ever.
NASA’s high-flying Reduced Gravity program
NASA’s Reduced Gravity Office has been an institution at the Johnson Space Center since 1959. It was used to support the Mercury missions, then Gemini, then Apollo, all the way through Skylab, the Shuttle program, and today’s International Space Station initiatives.
During that time, the custom planes have made more than 100,000 microgravity dives to support the training and testing associated with these missions. A microgravity dive is a parabolic arc wherein the plane dives at the same speed at which you fall — so within the plane’s enclosed cabin, it looks and feels like you’re just floating. NASA calls their plane the Weightless Wonder.
For all intents and purposes, the planes NASA uses are off the shelf. For the last while they have been using a KC-135A turbojet, but I got especially lucky while I was there. The turbojet was having some problems, so instead they resurrected an older C-9, one of the original Weightless Wonders. The interior is slightly smaller than the KC, but boy does it provide a smooth ride.
The exteriors of these planes don’t need to modified in any meaningful way. The stresses imparted onto the airframe during the dives and rapid climbs are all well within their designed tolerances. The real special sauce is on the inside. There are only about 20 seats, all of which are at the rear of the plane.
From there to the cockpit, it’s all laboratory. Every surface of the lab — the floor, walls, and ceiling — are padded with what seem to be white gym mats. This greatly improves safety, because you are absolutely going to hit your head (and everything else) until you figure out what you’re doing. Under the mats are intricate systems that allow you to bolt various items (palates full of lab experiments, for example) to the floor, so they won’t float away.
The windows are all shuttered during flight, because the illusion of placidly floating is most definitely ruined if you can see that in actuality, you’re falling out of the sky, and quickly. In lieu of windows, the cabin is outfitted with photographic lighting throughout, which provides a nice, even light.
I was brought in for the Reduced Gravity Education Flight Program’s annual flight week. The RGEFP has been a part of the Reduced Gravity Office since 1995, and since then every year it’s given students (and teachers) a chance to propose, design, build, test, and fly a microgravity experiment on a plane run by the Reduced Gravity Office. This is how it earned the moniker Microgravity University. This year NASA’s guidelines were that the experiments should focus on improving human spaceflight, and I was coming along to see it in action.
What it feels like
Let me start with a confession. Experiencing zero gravity is literally my oldest dream. In first grade my best friend and I spent countless hours trying to make an “anti-gravity potion” out of various household products. We accidentally poisoned the tree in my front yard trying to make it levitate (sorry mum). We were going to grow up to be scientists and we were going to figure out how to make humans fly, weightless, at will.
So to say that I was excited about the possibility of experiencing zero gravity would be a gargantuan understatement. In fact, I refused to let myself believe that it was really happening until the plane actually took off. But let’s back up. When it’s finally your day to fly, it goes like this.
Starting at 0745 (that’s military time, folks), teams have their mandatory flight day meetings and educations briefings with the flight crew. This is where final logistics are discussed and any last-minute problems are ironed out, if they can’t be. If not, the experiment doesn’t fly.
Then you get into your big, baggy flight suits, which have plenty of large pockets, mostly used for holding barf bags, so you can access them instantly, with either hand. Everyone is required to carry at least two. Some carry more. Only one person needed theirs on the day I flew, and the bags contained everything very neatly, thankfully.
At 0815 you have a half-hour medical briefing where you are told about the physiological effects of the parabolic flights. You are offered some airsickness medication. If you take it, your chances of getting sick during the flight are about 1 in 10. We were told that if you didn’t want to take it, your chances of getting sick were more like 1 in 3.
Everybody took it.
One of the most surprising things we learned is that it isn’t typically the zero-g dives that make people sick, it’s the 1.8g assents. You feel your guts being pulled down into the floor, and more importantly, it has a strong effect on the fluids in your ears which affect your sense of balance, and that’s what makes you nauseous.
We were told to not turn our heads quickly during ascent. Ideally, we shouldn’t move at all. If we must turn it was recommended that we turn with our whole bodies, rather than just our heads. It was suggested that we lie flat on our backs. “One in ten… one in ten…” I kept thinking to myself. “Is it going to be me?”
We sat in standard aeroplane seats, we took off, and headed out over the Gulf of Mexico. When we’d reached our cruising altitude of 26,000 feet, we were given the all-clear to get up. The students headed to their projects (more on those in another post), bolted down to the floor, and made sure everything was ready. Many lay down on their backs. And then the pilot hit the throttle and we started to climb.
Oh what a feeling…
1.8gs are plenty intense. I opted to lean back against one of the padded walls of the C-9, but I could see why so many chose to lie down. I could feel the blood in my head being pulled down toward my feet. I lifted up my arm and it felt like a weight was tied to it.
And then the plane came over the top. The engine quieted. The extra weight was lifted off of my body… and then all of the weight was gone. I was still on the floor, but I was no longer pressing into it. I gave myself the tiniest little push, and before I knew it, I was flying.
I was filled with such a complete sense of wonder and joy that I almost burst into tears. I had never in my life felt anything like this. It was a moment I had been dreaming about for more than 30 years — for as long as I can remember — and it was even better than I had imagined.
It’s also much harder to control than I imagined, despite having watched countless hours of footage of astronauts on the ISS. On Earth, if you sense you’re off balance, you grab onto something, right? Well, I felt myself drifting off, so I grabbed onto a ceiling strap.Before I knew what was happening, I was flat on the ceiling, and NASA’s crew was trying to pull me back down. Oops?
Twenty-five seconds later, and we were all back on the floor, beaming. All of the first time fliers were gut-laughing with ear-to-ear grins. There was a guy, roughly my age, from NASA JPL who just happened to be in town and was flying for the first time. He’s the guy in the blue suit in the top video who looks like he’s having the time of his life. That was how all of us felt. We couldn’t believe that has just happened.
What’s crazy is that there’s no in-between time between 0g and 1.8g. You know how when you’re riding your bike downhill, and you see you’ve got an uphill coming up, you try to use all that speed you’ve generated going downhill to help you start your next climb?
That’s exactly how these parabolic dives work. They use the momentum they generate on the dive to take them right into the next ascent. It’s much more energy efficient, but it also means that because you don’t spend any time 1g, you never really get to reset, and it can start to feel overwhelming.
I happened to be in the lucky majority and I didn’t get sick. This led me to be increasingly reckless as we went, and I would use our time spent at 1.8gs to crawl around and reposition myself to better see the different experiments. I even tried standing a couple times and man, you really feel it then. Instant quad-burn.
I had the opportunity to go inside the cockpit mid-flight. I stood behind the pilot, clutching the back of his seat as we climbed. It was the first time I could see out of the plane and it was much stranger to have contextual awareness. It wasn’t just that I was heavy, I was heavy and climbing, staring straight up at the blue sky.
How zero-gravity parabolas work
The science behind the zero gravity dive is actually very simple. There is no magical way to create anti-gravity or to build a zero gravity room that is somehow immune to gravity’s forces. So if you can’t beat ’em, join ’em.
Parabolic dives are, in fact, a state of free-fall. You’re basically sky diving; the only major difference is that you are in a fully enclosed space, so you can’t hear or feel the wind rushing past you, and you can’t see the rapidly approaching ground. You get that feeling in your stomach, like when you’re on a roller coaster and you take that first big drop, but then your other senses tell you that no, you’re not falling, you’re just floating there.
But I promise you, you’re falling. In fact, you’re falling 8,000 to 9,000 feet per dive.
If you were watching a dive from the outside, this is what you’d see. The plane flies out over the Gulf of Mexico and reaches a cruising altitude of 26,000 feet. Then it starts to climb at full speed, roughly at a 45 to 52 degree nose-high angle.
Inside the plane everything gets heavy. This is because the plane is pulling roughly 1.8gs, or 180% per cent of the Earth’s normal gravity. That means that if you weigh 80kg (which I do), suddenly it feels like you weigh 140kg. It is a major difference. But then the plane goes over the top of its arc — as if it were summiting a hill and dropping straight down the other side — and suddenly it’s diving nose-low and 45 degrees and you’re weightless.
Basically, the dexterity of the pilots (and NASA’s are the best in the business) keeps the plane diving at the exact speed at which you are falling. So, relative to you, it looks like everything is standing still, and you’re just floating there. It’s an intricate optical illusion.
The dive itself only lasts about 25 seconds, then the plane climbs again for a minute or so before heading back into its next dive. Repeat 30 times per flight, give or take. If you were to view it from far away it would like the plane were a rock skipping along an invisible lake.
When we nosed-over, I went totally weightless, while staring from the cockpit directly down at the ocean we were plummeting toward. It was thrilling. I wasn’t strapped in, either, so as we were falling, I was doing my best to grab onto unimportant objects to steady myself and keep from crashing into the console in front of the pilots.
After 15 parabolas heading outward, the plane turns around, and you do 15 more heading back. It took the students one or two parabolas at the outset to get used to the feeling and enjoy themselves, and then they got down to work. The were incredibly focused given the extraordinary circumstances. But more on that in tomorrow’s post.
After the standard 30 0g parabolic dives, we were given a little bonus. First we got to experience a lunar-gravity dive, which is one-sixth that of the Earth’s. I did a pushup, and ended up on my feet. I gave a little jump and I gently floated up and then sank back down. It made me think of all those videos I’d seen of astronauts skipping along the surface of the Moon, except I wasn’t weighed down by a heavy spacesuit and life-support system.
Finally, we got to do a Martian-gravity dive, which is one-third that of Earth’s. It was such an interesting hybrid feeling. I could walk around, but everything felt so easy. I did some one-handed clap-pushups like they were nothing. If we ever do end up colonizing Mars, basketball games are going to be amazing.
All told, we were out and back in under two hours. It was something I’d waited for my whole life, and then it happened and was over so fast.
I’m not good with ranking things, but it’s safe to say that my microgravity experience is solidly in my top-five all-time life experiences. Honestly, it’s very possible that it’s number one, bar none. I still get a thrill every time I think about it.
Pictures: Brent Rose with additional footage provided by NASA, edited by Nick Stango and Michael Hession
Gizmodo’s Space Camp is all about the under-explored side of NASA, from robotics to medicine to deep-space telescopes to art. All this week we’ll be coming at you direct from NASA’s Johnson Space Center in Houston, Texas, shedding a light on this amazing world. You can follow the whole series here.
Special thanks to everybody at NASA JSC for making this happen. The list of thank yous would take up pages, but for giving us access, and for being so generous with their time, we are extremely grateful to everyone there.
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This story was originally posted on Gizmodo in 2014.