Note: Astronomy Scope is reader supported. If you make a purchase through a link on our site, we may earn an affiliate commission - at no extra cost to you. This includes links to Amazon.

How Do Astronauts Train For Zero Gravity?

It might come as some surprise to you, but you can’t just sign on the dotted line with Nasa and then venture up into space. Astronauts have to train before they make that daring trip up into the cosmos. They have to train for a variety of different situations. One of those is the reality that there is zero gravity in space. Now you might be thinking, ‘how could they possibly train for that? All they need to do is just float’. Well, there’s a lot more to it than that, as we will now explore.

So, how do astronauts train for zero gravity? Astronauts train for zero gravity at a Zero Gravity Research Facility for up to 2 years. Their training consists of parabolic flights and free-falling simulation exercises. This helps accustom astronauts to the feeling of weightlessness that comes with zero gravity when they are up in space. As well as these practices, astronauts will train for extravehicular activities at a Neutral Buoyancy Laboratory where they are submerged underwater.

Zero gravity is an environmental factor of space that astronauts need to be very wary of.

It makes training all the more important.

As we shall see in the following few sections…

What Is Zero Gravity Training?

Zero gravity training is the process through which astronauts learn how to navigate an environment that is without gravity whilst remaining safe. 

Zero gravity can be pretty intense. But it needs to be. It is a situation that we Earthlings are not used to back home. We have gravity here; it’s what keeps us up on the ground rather than floating around like a bunch of wayward balloons. 

Up amongst the stars, it’s a whole different ball game. There is no gravity, which means astronauts will float around with limited control of their movements.

Astronauts need to be trained so that they can deal with this they can, be efficient in conducting their daily activities, and also so that they can remain safe up there.

How exactly do they train for zero gravity? Let’s get into the details…

What Is Included In Zero Gravity Training For Astronauts?

Zero gravity training for astronauts mainly consists of parabolic flights and free-falling practice at a Zero Gravity Research Facility. Astronauts will also practice spacewalks in a large underwater facility. 

Parabolic Flights

There are many exercises that make up the zero gravity training process. 

Funnily enough, a lot of this is to do with simulating the zero-gravity environment that is the cosmos. 

Astronauts at NASA train for zero gravity on parabolic flights. These flights can accurately recreate the sensations of free falling with a very technical method. 

During the parabolic flight, the plane will start to climb at a 45-degree angle once it exceeds 24,000 feet. When the plane reaches 34,000 feet, it dives back down towards 24,000 feet. Whilst this is happening, the training astronauts onboard will fall at the same rate as the plane is, creating that feeling of weightlessness for between 20 to 25 seconds.

Ever felt such a feeling for a second or two on a rollercoaster? Yep, that’s what NASA is going for here, just for a longer amount of time.

Through regular parabolic flights, astronauts can become more accustomed to the feeling of weightlessness they’ll experience when in a zero gravity environment up in space.

But that’s not all that is involved with the zero gravity training program.

Zero Gravity Research Facility

Nasa also puts astronauts through their paces at their Zero Gravity Research Facility.

Here, astronauts can consistently train for zero gravity inside a large steel vacuum chamber that is 432 feet long. 

A 5-stage vacuum pumping process reduces the pressure in the chamber to 0.05 torr. To give you an idea of how vastly different that is from normal, the standard atmospheric pressure is 760 torr.

When the chamber has this pressure level, a training astronaut will experience a nearly weightless free-fall environment for about 5.18 seconds.

So astronauts can also practice getting used to zero gravity environments by regularly using this vacuum chamber to experience the sensations of weightlessness.  

Spacewalks Training

The final part of their training doesn’t simulate a zero gravity environment, but it is very useful in training astronauts to complete extravehicular activities.

For those of you who don’t know, extravehicular activities are tasks that the astronauts have to perform outside of the space station whilst wearing a spacesuit. It’s basically a fancy term for spacewalks.

Astronauts wearing a spacesuit go underwater in what is called the Neutral Buoyancy Laboratory (NBL), which is basically a very big swimming pool that is 12 meters deep. 

By floating in the water, astronauts can practice extravehicular activities on full-sized space vehicle models.

Although there is gravity in water, it still provides a floating sensation that can help astronauts get used to it whilst performing extravehicular activities.

Where Do Astronauts Train For Zero Gravity?

Astronauts will train for Zero Gravity at a Zero Gravity Research Facility owned by the space travel organization they work for. NASA’s facility is located on their site in Brook Park, Ohio. They will also train for and practice spacewalks at The Neutral Buoyancy Laboratory, which is located at the Sonny Carter Training Facility in Houston, Texas.

So they’ve got to have some sort of high-tech facility to conduct this zero gravity training. And lucky for NASA’s astronauts, they have quite the place to prepare for the unpredictable conditions of space.

NASA’s Zero Gravity Research Facility is where astronauts will participate in the majority of their training for zero gravity conditions.

Other space organizations have similar facilities specifically designed for this type of training, but NASA’s is the largest of its kind.

Where can you find this facility? Oh, it’s just in the middle of Central Park.

Only kidding! NASA’s Zero Gravity Research Facility is one of the two drop towers found at NASA’s site in Brook Park, Ohio.

The facility was originally built in the 1960s to accommodate support research and development of space flight components and fluid systems in a weightless or microgravity environment.

Then, in 1966, the facility became operational as a zero-gravity training facility for astronauts. 

But to this day, it still accommodates research as well as training, particularly in the science of microgravity.

Then you have The Neutral Buoyancy Laboratory, which is where astronauts will train for and practice extravehicular activities whilst underwater. This is based at a different location, at the Sonny Carter Training Facility in Houston, Texas.

How Long Does It Take Astronauts To Train For Zero Gravity?

An astronaut training program could take up to 2 years to complete. Within this, there will be much practice in operating within a zero-gravity environment. Once NASA deems an astronaut fit for operating in a zero gravity environment, they will be able to travel up to space so long as they have completed the rest of their training.

Training to be an astronaut is no walk in the park. In fact, it can take up to two whole years of training before you can be qualified as an astronaut. 

These two years of training will cover everything they need to know, from learning the basic functions and configurations of the Space Shuttle they’ll fly in and the Space Station they’ll live on to zero gravity training.

Only when NASA believes a trainee is ready will they be given status as a qualified astronaut, which allows them to travel up to space.

You have to remember that NASA isn’t just training their astronauts; they are assessing them.

If an astronaut cannot cope with a zero gravity environment, then they may never be given status as a qualified astronaut. 

As trainee astronauts are being assessed, this means that the duration of a training program varies among the participants.

One astronaut might thrive in a zero gravity environment, meaning they’ll have to train for it for less time. On the other hand, another astronaut may struggle, meaning they need more time to train for the zero gravity they’ll experience in space.

Once an astronaut has completed their training, they can fly up to space. This could take two years, or it could be a little less.

Even if an astronaut copes very well during their zero gravity training, they will probably still undergo exercise, either on parabolic flights or in the vacuum chamber, so that they are consistently accustomed to zero gravity before they make that big trip up to the space station.


To some, zero gravity training might sound like a lot of fun. To others, maybe not.

But it is a fundamental aspect of an astronaut’s training program.

Otherwise, who knows where you might end up floating off to?

Related astronaut guides you may want to check out: