Make Mars' own planetary calendars, clocks, and wristwatches that are adjusted to "Mars time" and distribute them to all crewmembers going to Mars, digital cameras, video cameras (to show people on Earth how the crew is really doing), dozens of solar-powered generators, battery chargers, and hundreds of rechargeable batteries, 3 small multimeters - to test voltage levels because most rechargeable batteries are junk, [[ 50,000 oxygen tanks, 25,000 pounds of foods- 25,000 gallons of water in barrels and bottles of different flavored drinks for all passengers: the crew, and 20 animals (plus their future offspring... as mentioned on "Mars One hoax" page. Also, most can survive for days without food to eat nor water to drink. Yet, very few can survive for an hour without oxygen to breathe.): for them to be "kept alive on Mars" = 2 years of supplies ]], 5 bathtubs, 500 gallons of water in 25-gallon barrels to be used for bathwater: (recycled and reused by boiling or filtering it after each bath)
[*  Yes, there is some ice (frozen h2o?) on Mars.   However, it would probably only be equal to one lake full of water.   Important question, "What happens in a few years after all of those limited gallons of Mars' own water are used up from all of the crew's daily drinks, weekly baths, weekly watering of plants, weekly dishwashing, weekly loads of laundry, etc .?"   Answer: "Then, ALL water to be used on Mars will have to arrive from Earth, anyway!"  Indeed, the only THINGS that people must use to be kept alive on Mars will only be   THINGS FROM EARTH! *], 2 solar-powered cars with many spare parts, 5 three-wheel bikes with many spare parts, 2 deflated airship blimps and 5,000 xlarge helium or hydrogen tanks to inflate them, 5 utility tilt carts, 2 large telescopes, 10 towels, set of crutches, 2 wheelchairs (No broken bones ever on Mars is NOT likely, and no hospital, no emergency room... So, don't get pneumonia, nor frostbite!), deodorants, detergents, dishpans or buckets to soak/clean bacteria and germs off oxygen masks, dozens of lighters and matchbooks (They are the most vital items for survival on Mars, behind oxygen, food, and water! So, spread them around in different storage compartments, maybe near mounted fire extinguishers "to find them faster," throughout spaceship!), 20,000 pounds of charcoal, 20,000 pounds of firewood blocks, 5 large propane ovens, 5 coal stoves, and 5 barbeque grills- as cookers and heaters- , with 10,000 oxygen and propane tanks set apart to fuel them, 50 thermometers that are accurate at {-20°F<0}, 50 three-gallon 'heavy-duty' metal buckets that hold the hot burnt-up coals and smouldering firewood chunks/ashes - to be placed in different rooms as short-duration heaters, one rotating maintenance person on duty, at night, who checks indoor thermometers, replaces cold metal buckets with hot ones, and maintains indoor temperature above 30°F or hopefully warmer, sharp knives, saws, shovels (for graves, I mean for mining-lol), mentholated ointments, soaps, toothbrushes, dozens of tubes of toothpaste, bottles of cologne and perfume, eyeglasses with flathead and phillips tiny screwdrivers for their tiny screws, fingernail clippers, scissors, razors, shaving creams, mirrors, coats, parkas, insulated headwears, insulated underwears and socks, gloves, condoms (please- no dead babies on Mars! Please!), many bottles of hydrogen peroxide and hand sanitizer, lots of lurasidone, risperidone & some straight jackets -lol, crank/solar-powered gizmos, communicators, flashlights, table lamps, many spare bright "light emitting diode" lights! (cheap incandescent lightbulbs will burn out too quickly... maybe on purpose to sell more of them), dressers, tables, chairs, beds, blankets, sheets, pillows, bowls, dishes, cups, jars and bottles with lids, forks, knives, spoons, cards, dominoes, board games, pens, pencils, looseleaf paper packs, paper binders, paper notebooks, diaries, journals (spaceship's logbook, etc.) drums, guitars, horns, music instruction manuals, song books, frisbees, aerobic machines, exercise bikes, elastic workout bands, fitness manuals, soccer balls, trash bags/cans, backpacks, duffel bags, suitcases, ropes, tools- as many different tools as possible- since most of them will probably be used on Mars, industrial toolboxes on wheels, maybe building and construction materials- like ladders, wheelbarrows, sledgehammers, pickaxes, sheetrock, cement, lots of boards, bricks, hammers, nails, screws, nuts and bolts etc.?, rolls of insulated cords- cables- and wires, rolls of duct tape and clear packing tape, rolls of paper towels, hundreds of toilet paper rolls (lol), 100 one-pound bags of tropical trail mix- 100 twelve-packs of various beers (there is plenty of refrigeration for them on Mars)- with the MREs and other grub, and various subarctic evergreen tree seedlings, sods of the hardiest subarctic tundra grasses (used to begin terraforming Mars -lol, variety of seeds and seedlings of the hardiest grains, tubers, and other plants to be grown as Martian food stock, 500 gallons of water to irrigate them in some sort of circular, moat-like, waterwheel powered, flowing reservoirs, 2 pallet jacks, 10 pallets of 50-pound bags of potting soil, 10 pallets of "consecrated, and holy Miracle Grow" -lol, dynamite and explosives for mining, and many, many additional things, etc.  Please don't misunderstand me.  I really DO know that a manned mission on Mars is IMPOSSIBLE!  I included this Mars Mission Cargo Loadsheet (Inventory List of all loaded items brought aboard) just in case some fools still go to Mars, anyway.  Bring some shovels!
(Total "loaded" weight: = 2,500 tons or 5 million pounds! -- One more time... "Something as big as Starship Enterprise is necessary!"
...or total loaded weight redistributed by taking smaller loads on more trips to Mars.)