A zero gravity flight lets you experience brief periods of weightlessness using special aircraft and some pretty wild maneuvers. For a few moments, you’ll float just like astronauts do—without ever leaving Earth’s atmosphere.
A zero gravity flight pulls off real weightlessness by flying in parabolic arcs. The plane follows a specific path that cancels out gravity for everyone inside.
When the weightless phase kicks in, passengers float through the cabin. You might find yourself pushing off a wall or flipping in midair—there’s just nothing holding you down.
This isn’t some simulation or VR trick. People on board feel the same zero gravity that astronauts get in orbit.
Flights run several parabolas to stretch out the floating time. You’ll get more than one shot at drifting around the cabin.
Each weightless window lasts about 30 seconds. It’s not long, but trust me, it’s enough to get a taste of what floating in space is really like.
Parabolic flight has roots in NASA’s astronaut training. NASA built these flights into their programs to help astronauts prepare for weightlessness.
People started calling NASA’s first aircraft the “Vomit Comet”—early flights made a lot of folks queasy. Newer techniques and better prep have made today’s flights much easier to handle.
The military used these flights first for research and training. Scientists ran experiments in weightlessness to see how stuff—both living and not—behaves without gravity.
Later, commercial companies jumped in and adapted the idea for everyone else. Zero Gravity Corporation became the first FAA-approved company to offer public flights in the U.S.
The plane starts each parabola by climbing steeply, about 45 degrees, from 24,000 up to 32,000 feet. During this climb, passengers feel heavier—about 1.8 times their normal weight.
At the top of the arc, pilots push the nose over. Suddenly, the zero g environment sets in as the plane follows its curve.
The aircraft basically goes into free fall along the arc. Since everything inside falls at the same rate, you feel like you’re floating.
Pilots have to nail the descent to keep things smooth. This takes some real skill to keep everyone comfortable and safe during the parabolic flight.
Most flights run about 15 parabolas over 90 minutes or so. That adds up to about 7.5 minutes of floating, split across all those arcs.
Zero-gravity flights use specially modified planes that fly in precise parabolic paths to make weightlessness happen. The Boeing 727-200 is the main workhorse for these flights in the U.S., pulling off maneuvers that mimic the gravity you’d find on Mars, the Moon, or in space.
The Boeing 727-200 is the backbone of commercial zero-gravity flights here. Zero Gravity Corporation runs G-FORCE-ONE, a heavily modified 727 built for these wild arcs.
They took out most of the seats to create a 90-foot-long padded corridor. Up to 35 passengers and six crew members get to float in this play area.
Engineers made critical safety modifications for zero-g. They installed a closed hydraulic system to keep air and fluid separate during weightlessness, which helps maintain control during each maneuver.
Specialized equipment includes cockpit accelerometers. Pilots use these to track the flight path and speed, adjusting as needed for a smooth ride.
The 727-200 stays within its safety limits on these flights. Boeing designed it to handle forces from -0.1 G up to 2.5 G, but parabolic flights usually keep things between 0 G and 1.8 G.
Parabolic maneuvers make weightlessness possible by putting the plane—and everyone inside—into controlled free fall. The process starts with the aircraft flying level between 24,000 and 32,000 feet.
The climb phase begins when pilots pull the nose up to about 45 degrees. During this steep climb, passengers feel almost twice as heavy as usual—1.8 Gs.
At the top, pilots push the aircraft over and start a controlled dive. The plane follows a parabolic arc where gravity is the only thing acting on you and everything else inside.
This creates a weightless environment lasting about 22 to 30 seconds per parabola. Passengers float because they’re falling at the same speed as the plane.
Pilots tweak the shape of the arcs to simulate different gravity levels. Elongated arcs can create one-third gravity for a Martian effect, while other parabolas mimic the Moon’s one-sixth gravity.
Each commercial flight runs 15 of these parabolic arcs. The aircraft flies level between each one, giving everyone a moment to catch their breath.
The adventure starts with everyone buckled in at the back during a standard takeoff and climb. Usual airline safety steps apply here.
Once the plane hits the right altitude, passengers head to the padded play zone and stretch out for the first maneuver. Crew members announce each gravity phase—calling out “Martian gravity,” “Lunar gravity,” or “zero gravity” as it begins.
During reduced gravity, everyone can float, flip, and fly through the play area. Crew members are there to help out and snap photos or videos.
“Feet down” warnings let everyone know when the weightless period is ending. Passengers have to get ready for gravity’s return as the plane pulls out of the arc.
The whole flight gives you about seven to eight minutes of reduced gravity, spread across those 15 parabolas. After the last one, everyone heads back to their seats for landing.
Post-flight celebrations usually include champagne and souvenirs at the airport. From check-in to celebration, the experience takes several hours, though the flight itself lasts about 90 minutes.
A few specialized companies offer zero gravity flights in the U.S. ZERO-G Corporation leads the pack as the only FAA-approved provider. These operators use modified planes to give civilians, researchers, and commercial clients the real deal—authentic weightlessness.
ZERO-G Corporation is the top commercial zero gravity provider in America. They fly G-Force One, a tricked-out Boeing 727-200 that creates true weightlessness through those parabolic arcs.
The Zero-G Experience gives passengers 15 parabolas per flight. Each one delivers about 30 seconds of weightlessness, adding up to roughly 7.5 minutes total.
Flight Locations and Pricing:
ZERO-G boasts a spotless safety record—over 850 flights and 22,000 passengers. They serve public flights, private charters, research missions, and media gigs. Kids as young as 8 can join with an adult.
Aurora Aerospace is another player in the zero gravity market. They mostly focus on research and specialized training for aerospace pros.
Their modified aircraft handle NASA contractor training and university research. Aurora usually operates from select facilities, not on a fixed public schedule.
They can run custom flight profiles—simulating lunar gravity (one-sixth of Earth’s weight) or Martian gravity (one-third). That’s a big plus for space mission prep and research.
You’ll need to book in advance. Pricing isn’t public and depends on the mission, flight time, and number of people flying.
A handful of smaller companies offer specialized zero gravity services in niche markets. They don’t usually run regular commercial flights.
Some regional operators team up with certified providers to offer zero gravity flights from more locations. This gives people access to flights outside the main departure cities.
Aerospace contractors sometimes fly zero gravity missions just for government or military training. These flights help astronauts get ready and let teams test equipment for space.
International companies occasionally run flights in U.S. airspace by working with American authorities. These special flights pop up for certain events or limited times.
Zero gravity flights give you about 7.5 minutes of floating through 15 parabolic arcs, plus professional training and a little celebration at the end. The whole thing, from check-in to the final cheers, takes roughly five hours.
When you arrive, you’ll check in with your ID. Staff hand out boarding passes, flight suits, and some zero-g swag.
You’ll get a light breakfast—nothing too heavy, since that helps with motion sickness. Flight coaches run safety orientations on how to move and stay safe in zero gravity.
Training covers the basics:
The crew offers non-drowsy motion sickness meds and anti-nausea wearables if you want them. They explain what can make you feel queasy and how to dodge it.
After TSA security, you board the specially modified plane. Of course, there’s time for photos with the aircraft before you head out.
Once the plane hits the right airspace, flight attendants tell everyone to move into the padded zone and lie flat for the first parabola.
Each of the 15 arcs gives you about 30 seconds of pure floating. It’s the same weightlessness astronauts feel in space—no wires, no tricks.
During weightless periods, you can:
Professional photographers and cameras are everywhere, catching all the action. When the plane takes off, lands, or transitions between arcs, you’ll need to stay buckled in.
Flights also include lunar and Martian gravity phases. These let guests try out what it’s like to bounce around on the Moon or Mars—definitely a unique feeling.
The aircraft touches down, and the crew kicks off the Regravitation celebration. Someone hands out champagne or sparkling apple cider, and everyone raises a glass to making it through the zero gravity flight.
Guests get flight completion certificates and special pins to remember their weightless adventure. The crew also hands over detailed flight profiles, showing you exactly how the altitude and speed changed during each parabolic maneuver.
You can buy professional photos and videos from the flight if you want to relive the experience or show off to friends. Those images really capture the magic of floating and breaking free from gravity, even if just for a few moments.
People usually stick around to chat about what they felt and saw, swapping stories with other flyers and crew. Many say the sensation is completely unlike anything you can feel on solid ground—hard to describe, but unforgettable.
Staff help collect flight suits and handle any last-minute zero-g merch purchases. The whole post-flight routine wraps up pretty quickly, usually within an hour after landing.
Zero gravity flights give you a genuine weightless environment, and your body reacts right away. The feeling is nothing like what you deal with day to day, but you’ll probably find your body adapts surprisingly fast during each 20-30 second weightless interval.
As soon as weightlessness hits, you feel completely free from gravity’s grip. Your body just floats, and suddenly there’s no sense of up or down.
First-timers often get caught off guard by the sensation. Some say it feels like falling, while others compare it to floating underwater—but with zero resistance.
Physical sensations include:
Your inner ear, which handles balance, sends mixed messages to your brain in true weightlessness. That confusion can leave you briefly disoriented as your body tries to figure things out.
Some people notice a gentle pull in their stomach, which is just your organs floating around a bit without gravity holding them down.
You can move in any direction with hardly any effort. Push off a wall, and you’ll glide across the cabin with almost no resistance.
Weightlessness hits several body systems at once. Your cardiovascular system gets a break because blood doesn’t pool in your legs anymore.
Facial puffiness can happen since body fluids shift toward your head and chest instead of sinking down.
Your vestibular system works overtime, trying to make sense of the new input. The inner ear’s balance organs notice the lack of gravity and react.
About 30% of first-timers deal with some motion sickness. It ranges from a little nausea to more serious discomfort, especially during the switch between gravity phases.
Your nervous system scrambles to process signals from your eyes, ears, and body position sensors. That sensory mix-up is what creates the signature floating feeling.
Most people start getting the hang of weightlessness after a few parabolas. Your brain learns fast, and soon you’re moving more confidently.
At first, movement feels awkward. But after a bit, you realize gentle pushes and small motions work way better than anything forceful.
Adaptation strategies include:
Your proprioceptive system—basically your internal GPS—recalibrates with each weightless period. That helps you figure out where you are in the cabin.
People with experience say they feel more comfortable with every new parabola. The more time you spend weightless, the easier it gets to move around.
By the end of the flight, most folks are gliding smoothly and confidently. That initial confusion fades, and you start to really enjoy moving in three dimensions.
Zero gravity flights don’t just offer pure weightlessness—you can also try out lunar and Martian gravity. The crew uses special parabolic arcs to match the gravity you’d feel on the Moon or Mars.
Lunar gravity simulations let you feel what it’s like to weigh just one-sixth of your normal body weight. During these arcs, you tip the scales at only 17% of your usual weight.
The plane flies a wider curve at the top of the parabola to keep this reduced gravity going. For a little while, you get a real taste of lunar conditions—no rocket required.
Movement characteristics in lunar gravity are wild. You can take giant leaps across the cabin and move in slow motion, just like those Apollo astronauts.
Walking turns into bouncing. Each step sends you higher, and even a little arm motion can lift you off the floor. It’s a close match for what future Moon tourists might experience.
Martian gravity is about one-third of what you’re used to, so you’ll feel 38% of your normal weight during these flights.
Mars gravity creates its own quirks. You stay grounded better than in lunar gravity, but you’re still much lighter than on Earth.
Physical sensations include being able to jump higher and lift things with almost no effort. Your arms and legs feel light, and you can hold them up for ages without getting tired.
Martian gravity flights give you a sense of what daily life might be like on the Red Planet. It’s an eye-opener for anyone curious about how humans could adapt to living and working on Mars.
Zero gravity flights in the U.S. come in three main flavors, so there’s something for every budget. You can grab a seat on a public flight for $8,900, or go all-in on a private charter for $259,000.
Public flights are the most affordable way to try zero gravity. Book early—over 60 days out—and you’ll pay $8,900 plus tax for a seat.
You’ll share the cabin with other passengers, most of whom you probably won’t know. Each flight does 15 parabolic maneuvers, giving you about 30 seconds of weightlessness per arc.
Your ticket covers everything: a flight suit you get to keep, pre-flight training, and safety briefings. After landing, you’ll celebrate with champagne and get a completion pin.
Public flights operate from big cities all over the U.S. You’ll find departures from Cape Canaveral, Las Vegas, San Francisco, Austin, Dallas, Atlanta, Chicago, New York, and Washington DC.
Zero-G Corporation runs these flights year-round. They’ve kept a spotless safety record, flying more than 22,000 passengers on over 850 flights during the past 20 years.
Private flights are perfect for groups who want the whole cabin to themselves. There are two main private options, depending on your group size and budget.
Half-plane sections run $116,000 plus tax for up to 14 people. You get your own floating zone, separate from everyone else, and a dedicated photographer captures the whole thing.
Full private charters cost $259,000 plus tax and give you the entire aircraft for up to 28 passengers. You’ll get 15 parabolic maneuvers and total privacy, plus a photographer just for your group.
Companies use private charters for team building and marketing stunts. Media crews book private flights to shoot realistic space scenes for movies and commercials.
People even hold weddings and big celebrations on these flights. You’ll never forget floating down the aisle or celebrating a milestone in zero gravity.
Research flights help scientists and engineers test new tech for space. These flights provide controlled weightless environments for all sorts of experiments.
Researchers use these flights to test equipment before sending it into space. The flights can simulate lunar, Martian, or full zero gravity, letting engineers gather data and tweak their designs.
NASA and private aerospace companies book these flights all the time. They test life support systems, manufacturing processes, and more. Universities also use them for student projects and astronaut training.
Research flights follow the same safety rules as public flights. The Boeing 727 does the same parabolic maneuvers, but the cabin gets reconfigured for science gear instead of tourists.
These missions move space technology forward. Data collected here helps shape future spacecraft and mission plans.
Zero gravity flights in the U.S. take off from several key spots. Florida, Nevada, and California serve as the main hubs, but the flights also swing through big cities like New York, Chicago, and Los Angeles on a rotating schedule.
Florida is the heart of Zero-G operations, with regular departures from the Tampa Bay area near St. Petersburg. The state’s great flying weather and solid aviation infrastructure make it the perfect home base.
G-Force One flies out of Florida a lot. The crew takes advantage of the weather and the experienced aerospace workforce. St. Petersburg’s location near major airports also makes it easy for travelers from the Southeast.
Primary Florida advantages:
Florida flights usually run on the most consistent schedule. The state’s position lets the aircraft fly longer parabolic arcs over the Gulf of Mexico—ideal for creating weightlessness.
Zero-G brings its plane to major cities all over the country on a rotating schedule. Las Vegas and San Francisco are the other main hubs, along with Florida.
Cities like Austin, Dallas, Atlanta, Chicago, New York, and Washington DC get regular visits. The aircraft moves between these spots depending on demand and the time of year.
West Coast flights center on San Francisco and Los Angeles, making it easy for Californians and folks from the Pacific Northwest.
East Coast cities like New York and Washington DC get the aircraft several times a year, serving the busy corridor from Boston to Atlanta.
This rotating schedule helps Zero-G reach a lot of people while staying efficient. You can either travel to Florida for more frequent flights or wait for the plane to come to your area.
Florida’s space coast brings something extra to the table. Being close to Kennedy Space Center makes the whole experience feel more “space-y.”
Kennedy Space Center offers a lot of perks. The region is packed with aerospace experts and facilities designed for space activities. That deep pool of knowledge helps Zero-G run smoothly.
The Space Coast region gives passengers more ways to dive into space culture. Many people pair their zero gravity flight with a tour of Kennedy Space Center or other local attractions.
Ground operations benefit from all the aerospace infrastructure nearby. Specialized maintenance, experienced techs, and industry suppliers make things safer and more reliable.
There’s also a cool educational angle. Flying near where astronauts train and launch connects you to America’s space history and future in a pretty real way.
Zero gravity flights in the U.S. range from $8,900 for a single seat to $259,000 for a private charter. Most packages throw in a flight suit, some merch, and official documentation of your adventure.
Zero-G Corporation has three main pricing tiers for weightlessness flights. If you book more than 60 days ahead, you’ll pay $8,900 plus tax for an individual seat.
A half-plane section fits up to 14 people for $116,000 plus tax. This option gives your group a private floating zone, away from other guests.
Full private flights go for $259,000 plus tax and let you and up to 28 people have the whole aircraft to yourselves.
Pricing Structure:
| Option | Capacity | Price | Advance Booking |
|---|---|---|---|
| Individual Seat | 1 person | $8,900 + tax | 60+ days |
| Half-plane | Up to 14 people | $116,000 + tax | 60+ days |
| Private Flight | Up to 28 people | $259,000 + tax | 60+ days |
Kids 8 and up can join in. If they’re 8-13, each one needs their own guardian. Teens 14-18 just need solid supervision.
Every zero gravity flight features 15 parabolic maneuvers. You get about 30 seconds of weightlessness with each one.
You’ll keep your flight suit after the flight. Zero-G gives you this special suit to keep you comfortable and safe while you float.
Zero-G merchandise comes with every ticket. You’ll get branded goodies to remember your weightless experience.
The package also covers a light breakfast before takeoff and a champagne toast at the “Regravitation celebration” afterward.
Professional photographers and videographers document your whole adventure. You’ll get free photos and videos of yourself floating in zero gravity.
Every flyer gets a completion pin. If you’re worried about motion sickness, you can opt for anti-nausea medication or try out wearable devices during the flight.
Zero-G flies out of several cities across the U.S. Main departure points include Cape Canaveral (Florida), Las Vegas (Nevada), and San Francisco (California).
You’ll also find flights from Austin and Dallas (Texas), Atlanta (Georgia), Chicago (Illinois), New York, Washington DC, and Fort Lauderdale (Florida).
The company keeps an updated flight schedule year-round. They release specific dates as soon as they finish planning for the coming months.
Booking early—more than 60 days out—locks in the standard price and avoids extra fees.
You’ll need medical clearance to reserve a spot. Zero-G sticks to strict safety rules that they’ve honed during over 11 years of FAA certification.
Private charters are available for special occasions. Corporate groups, weddings, media shoots, and marketing events can book the whole plane.
Zero-G flights run under tight FAA oversight and follow detailed safety protocols and medical rules. Zero-G Corporation keeps a spotless safety record by sticking to commercial aviation standards.
The Federal Aviation Administration puts parabolic flight operators under Part 121 safety standards—the same ones that big airlines like Delta and Southwest follow.
Zero-G and similar companies have to get extensive FAA approval before flying the public. Zero-G Corporation spent over 11 years getting their initial certification. That long process made sure their aircraft modifications matched commercial aviation requirements.
Key regulatory areas:
The FAA makes operators explain the sensations and possible risks of parabolic flight to passengers. Everyone needs to know what to expect before takeoff.
Commercial liability rules protect both companies and travelers. If anything happens, the FAA investigates under standard procedures for commercial aviation.
Zero-G Corporation has kept a perfect safety record over 850+ flights and 22,000 passengers in 20 years. That says a lot about their safety protocols.
Their modified Boeing 727 gets thorough maintenance. Mechanics pay special attention to engine systems since zero-g segments can mess with oil pressure.
Safety protocols:
Parabolic flights create up to 2.5 Gs during pullup maneuvers. Passengers feel 1.8 Gs on the way up, then float in weightlessness.
Each zero-g segment lasts about 30 seconds. The short duration helps keep everyone—and the plane—safe and comfortable.
Passengers must be at least 8 years old for zero-g flights. Kids 8-13 need a guardian with them at all times.
Medical fitness standards depend on the operator. Some require a doctor’s note, especially for older passengers or folks with health issues.
Common medical restrictions:
Fewer people get motion sickness than you might think. Operators hand out non-drowsy Dramamine and anti-nausea wearables on flight day.
Flight coaches teach you how to position your body to avoid discomfort. Quick head movements can trigger nausea, so they’ll show you how to move smoothly.
Before the flight, you’ll get tips on eating a light breakfast and staying hydrated. Instructors explain what causes motion sickness and how to avoid it during your parabolic adventure.
Getting ready for a zero gravity flight isn’t complicated, but knowing what’s coming makes everything easier. Most companies provide flight suits—your job is to show up prepared and follow a few simple guidelines.
Wear comfy, snug clothes under your flight suit. Athletic wear or fitted casual clothes work best; baggy stuff can get in the way when you’re floating.
Zero gravity operators give you a special flight suit to wear. It’s designed for safety and freedom of movement, and you get to keep it afterward.
Closed-toe shoes are a must. Sneakers or any comfy athletic shoes are perfect. Leave sandals, heels, or open-toe shoes at home.
Take off jewelry, watches, and other loose items before boarding. In zero-g, they can turn into dangerous projectiles.
You’ll also get some cool Zero-G merchandise as part of your package. Think certificates, photos, videos, and branded souvenirs to remember your flight.
Before the flight, you’ll go through a detailed orientation about safety procedures and how to move. Instructors explain how to control your body and avoid bumping into others.
Most companies offer anti-motion sickness medication like Dramamine. They’ll also give you wearables and a light breakfast to help prevent nausea.
Flight coaches show you the best ways to move in zero gravity. They’ll teach you to push gently off surfaces and avoid sudden movements for maximum fun and safety.
You’ll learn about the parabolic flight pattern—the 1.8G climb, 30 seconds of weightlessness, then a gentle return. Knowing what’s coming helps you stay relaxed.
Instructors also go over breathing and relaxation techniques. Staying calm and following their guidance makes your weightless adventure safer and more enjoyable.
Zero gravity flights give you professional photos, videos, and keepsakes to remember your adventure. Companies include certificates and branded merchandise in every package, so you’ll have plenty of ways to relive the day.
Pro photographers place cameras around the cabin to catch every wild moment. The padded interior turns into a zero gravity playground, and cameras record you floating, flipping, and doing things you probably never imagined.
Operators give you free photos and videos with your package. They record all 15 parabolic arcs, so you’ll see yourself floating for 20 to 30 seconds at a time.
The footage captures genuine reactions and moves you might not even remember because it all happens so fast. Multiple camera angles make sure they don’t miss a thing.
You’ll get a DVD or digital files of your flight. It’s a great way to show off your zero-g skills to friends and family who stayed on the ground.
Every passenger gets an official certificate for completing the zero gravity flight. It proves you did it and makes a fun conversation starter.
Zero-G merchandise is standard with every ticket. You’ll keep your flight suit as a souvenir.
Expect extra goodies like patches, pins, and other keepsakes. These mementos go nicely with your digital memories from the flight.
Having both certificates and merchandise gives you lasting reminders of your adventure. Most people end up displaying them or sharing stories about their time in simulated space.
Zero gravity flights get a lot of questions about pricing, booking, and safety. These experiences range from more affordable parabolic flights to deluxe packages, each with its own details.
Most zero gravity flights cost between $5,000 and $8,000 per person for a standard parabolic experience. That price includes the flight, pre-flight training, and all your safety gear.
Premium packages—with extra perks—can run up to $15,000. Some companies offer group deals or seasonal sales to bring costs down.
You’ll get about 15 parabolic arcs per flight. Each one gives you roughly 30 seconds of weightlessness.
Zero-G Corporation is the main company running zero gravity flights in several U.S. cities. They offer public flights from different locations all year.
The Aurora Aerospace Training Center in St. Petersburg, Florida offers private zero gravity experiences. It’s close to Kennedy Space Center.
Other companies fly from various places depending on demand. You can book directly on their websites or through travel partners.
A full zero gravity flight usually runs 90 minutes to two hours, start to finish. The actual weightless time adds up to 7-8 minutes, spread over several parabolic arcs.
Each arc takes about 10 miles of airspace. You’ll go through 15 maneuvers in a typical session.
Flights also let you try lunar and Martian gravity for a bit. These happen between the zero gravity segments.
Public zero gravity flights are the most budget-friendly way for regular folks to experience weightlessness. They’re way cheaper than full-blown space tourism.
Some places offer payment plans or financing to help with costs. If you book as a group, you might get a discount.
Wind tunnels and special training centers offer lower-priced options that mimic some weightless sensations, but they can’t fully match real zero gravity.
Zero gravity flights use specially modified planes that meet strict standards for parabolic operations. Experienced test pilots fly these aircraft.
Flight crews help guide passengers during weightless periods, making sure everyone stays safe and avoids collisions. You’ll get pre-flight safety training and wear protective gear.
The aircraft get regular maintenance for the unique demands of these flights. Medical screening makes sure you’re ready for the changes in gravity.
Parabolic flights actually create weightlessness. Pilots fly along special paths that cancel out gravity for a short time.
Indoor experiences? They usually use wind tunnels or suspension rigs to give you that floating feeling.
You only get real zero gravity during a parabolic flight. The plane follows a specific arc, and for a few moments, gravity just isn’t there.
You won’t find that in indoor facilities. They just can’t fully remove gravity, no matter how high-tech they get.
Zero gravity flights sometimes let you feel different gravity levels, like what you’d get on the Moon or Mars. Indoor setups mostly stick to simulating a general floating sensation, not true weightlessness.
