Bouncing, Floating, and Being Sick: Adventures on Parabolic Planes

In my line of work, I'm asked about my “zero G” reduced gravity parabolic flight experience often. I've been privileged to fly twice so far, both times as a researcher. It was one of the coolest, most exciting things I've ever done. I'm looking forward to flying again! I highly recommend it to anyone, as a joy ride or as a microgravity experience. It was exhilarating.

Graphic courtesy of my company, S3

As a physicist, I can't bring myself to ever call these flights “weightlessness” and I hesitate to even write “zero g.” I commonly use the term “microgravity” when discussing payloads and experiments, but even that can be inaccurate. NASA uses the term “reduced gravity” and ESA uses the term “parabolic,” both of which are more accurate. Companies such as my own who cater to a more general public tend to use catchphrase Zero G.

During these flights, the aircraft is in a state of temporary freefall. To gain perspective, human-made satellites including the International Space Station, the Moon, and everything that orbits Earth is in freefall around Earth. Earth's gravity always exists but can be canceled out, so it's more accurate to speak in terms of net gravity. We drop the word “net” for convenience.

Weightlessness or zero g (0 g) can only be achieved in perfection. Near to perfection, microgravity (0.000001 g) conditions may exist in space, but not on aircraft flying through Earth's turbulent atmosphere. The most these flights can hope to achieve is centigravity (0.01 g), or if they're really good, milligravity (0.001 g).

“Reduced gravity” is accurate and accounts for lower gravity analogs such as lunar gravity or Martian gravity, but ignores the hypergravity conditions when the plane is flying upward at nearly double normal gravity (1.8 g). “Parabolic” is the most accurate term of them all because it describes the motion of the aircraft as being large parabolas or arcs.

My first flight was on a Zero G Corporation plane here in Florida in November 2011. At the time, I was studying for my doctoral candidacy exam and preparing our experiment for flight, so I was preoccupied with technical details and not focused on the flight itself. The closest I got to contemplating my upcoming adventure was riding a theme park ride that threw around my body and thinking, “Wow, these sudden G force changes are good practice for next weekend.”

There is no sideways, not on this plane! - November 2011

It was very cold on the plane. I soon learned that this was done on purpose to minimize overheating which can lead to being sick. These aircraft weren't given the nickname “vomit comet” for nothing. My flightsuit was huge on my petite frame, but I pinned it well enough to be able to move in it. I quickly learned that agility was beneficial while floating around nearly uncontrollably as a first timer.

Microgravity isn't like flying. It's not like swimming or scuba diving, even though astronauts practice underwater to train for it. It isn't like being at the top of a roller coaster. It was like someone flipped a switch and gravity just turned off.

I had very little control over my movements. Each move I made was exaggerated and counter-intuitive. I felt like a rubber ball that had gone out of control and was bouncing off of the floor, ceiling, and walls, only in this case there was no difference between the floor, ceiling, and walls, all were the same. I expected to fly like Superman or do somersaults or just hover, but those maneuvers take practice. It was all I could manage to keep control of my movements. I had a blast!

Houston, August 2012

About to board the plane - August 2012

My second flight was in August 2012 at Ellington Field in Houston with NASA's Reduced Gravity Program. I felt a lot calmer right off the bat because I knew what to expect and how to react to reduced gravity. I was like a flag blowing in the wind, only without wind. I held on to the experiment with one hand while my legs stayed together and swayed horizontally (for the most part) and my other hand worked.

Unfortunately, I personally learned about the nickname “vomit comet.” I had declined the optional anti-nausea medication for both flights, and this time, the changing gravity caught up to me. By parabola 22 of 40, I was down and out. When we landed and I finally escaped the plane, I literally got down on my knees and kissed the ground! But, as sick as I was, I would sign up to do it again in a heartbeat.

Whether you're a scientist or an engineer with an experiment or payload to test in microgravity conditions or an average person with an adventurer's spirit, I highly recommend signing up for a flight if you get the chance. I'm so grateful for my flights. It'll be an experience you'll never forget!