Astronauts bring a carefully curated mix of personal mementos, digital entertainment, specialized food, and practical gear, all constrained by strict weight limits and safety rules. Every kilogram launched to the International Space Station costs roughly $23,300 on a SpaceX Falcon 9 mission, so nothing goes up without good reason. Here’s what actually makes the cut.
The Personal Preference Kit
Every astronaut is allowed a small bag of personal items called a Personal Preference Kit, or PPK. This tradition dates back to the earliest days of spaceflight. Apollo 11 astronaut Michael Collins packed three flags in his: the U.S. flag, the flag of the District of Columbia, and the U.S. Air Force flag. The concept hasn’t changed much since then. Astronauts use this allotment for small, meaningful objects like family photos, religious items, patches, pins, or keepsakes they want to carry beyond Earth’s atmosphere.
The kit has strict size and weight limits, so everything in it tends to be compact and lightweight. Wedding rings, small toys belonging to their kids, university flags, or sentimental jewelry are common choices. Some astronauts carry items on behalf of organizations or charities, giving those objects the distinction of having flown in space.
Food That Works in Microgravity
Space food has come a long way from the squeeze tubes and freeze-dried cubes that early Mercury astronauts endured. Most of them found those meals unappetizing, and the freeze-dried versions were difficult to rehydrate. Today’s menu aboard the ISS includes roughly 200 items spanning several categories.
Rehydratable foods cover soups (chicken consommé, cream of mushroom), casseroles (macaroni and cheese, chicken and rice), appetizers like shrimp cocktail, and breakfast items like scrambled eggs and cereals. Thermostabilized foods, which are heat-processed to kill harmful microorganisms, include most fruits and canned fish like tuna and salmon, plus entrées such as beef tips with mushrooms, chicken à la king, and ham in flexible pouches. Irradiated meats, nuts, granola bars, and cookies round out the options.
Condiments come in individual pouches: ketchup, mustard, mayonnaise, taco sauce, and hot pepper sauce. Salt and pepper exist only in liquid form. Salt is dissolved in water and pepper is suspended in oil, both stored in small dropper bottles. Granular versions would float away in microgravity, potentially irritating eyes or clogging air vents. Flour tortillas replaced bread in 1985 because they don’t produce crumbs that could foul instruments or float into someone’s lungs.
Digital Entertainment and Comfort Items
Long-duration missions demand serious attention to mental health, and much of what astronauts bring serves that purpose. Each crew member has access to devices loaded with their favorite movies, TV shows, books, playlists, podcasts, and audiobooks. Canadian astronaut Chris Hadfield used to watch recordings of Toronto Maple Leafs hockey games while running on the treadmill. David Saint-Jacques read bedtime stories to his three children via video call during his mission.
Internet phones, videoconference systems, and even virtual reality headsets let astronauts stay connected with family and friends on Earth. During downtime, crew members read, play musical instruments, listen to music, journal, meditate, or simply watch Earth pass by through the station’s windows. Photos and small objects that remind them of home are kept in their private crew quarters, much like you’d decorate a bedroom.
Care packages on resupply missions also play a surprising role in morale. These often include sweets, small gifts, letters, and birthday cards from family. For missions lasting six months or longer, those little reminders of home carry outsized psychological weight.
What’s Banned and Why
The sealed, oxygen-rich environment of a spacecraft makes certain materials genuinely dangerous. Glass containers are prohibited because shattered glass in microgravity would be nearly impossible to clean up, with tiny shards drifting through the air and into lungs or eyes. Flammable liquids, spray paint, and aerosol sprays pose fire risks in a pressurized cabin where a blaze could be catastrophic. Anything that produces loose particles, sharp fragments, or uncontrolled projectiles is a nonstarter.
Materials brought aboard go through extensive screening. Items must be tested for off-gassing, meaning they can’t release toxic fumes in the station’s closed-loop air system. Certain plastics, adhesives, and fabrics that seem harmless on Earth can slowly emit chemicals that build up in a sealed environment. Even personal items in the PPK go through review to make sure they won’t compromise air quality or crew safety.
Why Every Gram Matters
The cost of getting anything to orbit shapes every packing decision. A Falcon 9 and Dragon capsule mission to the ISS runs about $140 million for 6,000 kilograms of payload. That works out to roughly $23,300 per kilogram, or about $10,500 per pound. During the Space Shuttle era, the cost was far steeper: approximately $93,400 per kilogram because the shuttle carried less cargo to ISS despite its larger overall capacity.
This economic reality is why astronauts can’t simply pack a suitcase. Personal allowances are measured in grams, not pounds. Clothing is minimal and often worn for days before being discarded (there’s no laundry machine on the ISS). Tools and equipment serve multiple purposes wherever possible. Even water is recycled from humidity, sweat, and urine rather than launched fresh, because every liter sent up represents thousands of dollars in launch cost.
Clothing and Daily Essentials
Astronauts wear standard cotton or cotton-blend shirts, shorts, and socks aboard the station. There’s no washing machine, so clothes are worn until they’re too dirty, then packed into a cargo vehicle that burns up on reentry. A typical crew member might change shirts every few days and underwear and socks somewhat more frequently.
Hygiene items include rinseless shampoo, toothpaste (which gets swallowed rather than spit out), wet wipes for bathing, and deodorant. Razors are available but used carefully, with shaving cream applied close to the face and whiskers captured immediately to prevent them from floating into electronics or ventilation systems.
Sleep Station Setup
Each astronaut gets a small private crew quarter, roughly the size of a phone booth. Inside is a sleeping bag attached to the wall so you don’t drift while sleeping. A small ventilation fan is essential because without gravity, the carbon dioxide you exhale doesn’t sink away from your face. It pools around your head, and without airflow you’d wake up with a headache or worse.
Crew quarters also hold a laptop for personal use, any photos or small keepsakes from the PPK, and sometimes a reading light. It’s the closest thing to private space on a station shared by six or more people, and astronauts tend to treat it as their personal sanctuary for the duration of their mission.