Sitting in a tin can

What could make a person lock himself in a tin can capsule and shoot himself deep into space? The incredible thirst for knowledge that unites us
History of human-rated space capsules

It takes courage, it takes a mountain of courage (and a pinch of madness) to sit on tens of meters of explosives in a thin can ready to be fired into the cold and dark space. And it is precisely this courage that has distinguished the first pioneers of human space exploration, from the first Soviet mission to the first NASA Mercury program, the courage of these men and the trust they placed in technicians and engineers still today almost 60 years later echoes in our minds and imaginations. Try even for a few seconds to close your eyes and imagine being there, with the suit on, sitting in a fetal position to attenuate the G-force surrounded by cables, lights, hands, and indicators of all the onboard systems in a capsule slightly larger than a telephone booth. It really takes courage.

But precisely what did these adventurers sit on? All of this is evident before the eyes of the world on April 12, 1961, with the Vostok capsule, a capsule with a length of 2.25 meters and a diameter of 2.43 meters and a mass of 2270 kg was the first specimen of its kind, a concentrate of technology that with the cosmonaut on board Yuri Gagarin performed the first launch with humans on board in history. Initially developed also to be a spy satellite with onboard cameras of various types, the same type of architecture has been used for over 40 years for various models of satellites.

Remaining in the lands of the Soviet Union follows the older sister Voskhod, built by heavily modifying the Vostok the Voskhod did not have a mission abortion system, and several systems and apparatus were also moved to accommodate a crew of 2/3 Cosmonauts, but the very little internal space cosmonauts could not wear the flight suits being very bulky, exposing occupants to enormous risks in the event of decompression. With the first launch occurred in 1965 the second version, the Voshod 2 allowed the two Cosmonauts on board to carry out the first EVA (Extra Vehicular Activity) in history thanks to the presence of an inflatable airlock on one side of the capsule to allow the compression and decompression of the chamber to enter and exit outside in the cold and dark space.

Voshod 2 capsule with the inflatable airlock Credits: Fantascienza italia

Let’s move overseas to meet the first capsule of what was once the NACA (then NASA), the first to be designed and built explicitly to bring humans up into space, for this as a crew was chosen the best test pilots on American soil then called the “Mercury Seven”. So to recap, we have the best pilots in a brand-new capsule…  For this reason, we build it without controls and flight surfaces or windows, exactly even the astronauts in the hangar of the swamp of cape Canaveral had to have confused, and dismayed faces at seeing that trunk of metal cone closed, in fact, like a tin can. from there it was decided to compromise by making some changes such as tools for the telemetry of the trim and a wonderful window to enjoy the view, but always without controls to govern the capsule on board. This capsule over the years made several launches the first in September 1959, being converted for both the first Redstone rockets and the more powerful Atlas.

Mercury diagram with all onboard systems – Credits: Wikipedia

Now let’s move on to the older sister of the Mercury, the Gemini capsule, one of the most important and long-lived in American space history. Starting from geometry similar to the previous heavily modified Mercury was first of all able to accommodate two astronauts on board, it had an electronic system capable of being repaired and replaced much more easily than the previous capsule.

One of the differences that most catches the eye is the lack of an escape tower on the muzzle, this is because the eventual explosion of the powerful titan rocket on which the capsule was launched would have been too immediate to allow safe escape, so it was opted for a more traditional aeronautical ejection seat, exactly that the astronauts literally threw themselves out of the capsule. Obviously, this system could not be used beyond certain altitudes and speeds, so in case of problems during the flight at high altitude, it was decided simply to separate the and land it normally.

The Gemini was the first capsule with astronauts to carry an on-board computer, the Gemini Guidance Computer, also called Gemini Spacecraft On-Board Computer (OBC) was at the forefront of managing routes and trim, in the future a very similar version will also be used for the Apollo missions.

Apollo capsule is not long in coming and promises to be the largest, most massive, heavy, and complex can that man has ever conceived to bring three men not only into space or orbit but to the Moon (maybe landing there as well).

After the first launch test in 1966 with a Saturn Ib, everything seems to work perfectly but later with the tragic accident of Apollo 1 where all 3 astronauts perished in a huge fire the capsule was heavily modified, eliminating all flammable materials (including astronauts’ suits) replacing with fireproof coatings.

The capsule was a jewel of electronics and technology, for the first time you had to deal with a prolonged space journey having to deal with many obstacles, including radiation, prolonged life support, and communications that should never be missing between the capsule and the Earth.

Another incredible apparatus was the heat shield used for re-entry to the ground at speeds considerably higher than those of the previous capsules.  The docking system was also greatly perfected by the Gemini missions, essential to dock to the landing module, guaranteeing solidity and safety to the entire complex travel system.  Decommissioned in 1975 also participated in the Skylab missions (the first American space station) and was the first capsule to dock with the capsule of a “rival” country with the Apollo-Soyuz mission

Apollo capsule diagram with the main onboard system and the three astronauts’ configuration – Credits: Pinterest

let’s return overseas again in 1966 when at the same time as America in the lands of the USSR, was developing the first capsule capable of hosting three cosmonauts, the Soyuz. Still used today is the longest-lived capsule in history, having completed more than 140 flights, operated with Soyuz launchers has served all kinds of missions, from primary historical docking with the Apollo capsule to routine flights to the ISS.

The basic design has remained the same all these years, consisting of three segments; an orbital spherical module, a bell-shaped descent module, and a cylindrical service module equipped with solar panels and all life support equipment have a survival capacity for three astronauts for about 30 days in orbit.

Over the decades, it has been the most modified capsule seeing dozens of variants, the most recent is the Soyuz MS, first launched in 2016 and still in use today. It features extremely advanced onboard systems between communication and navigation subsystems.

Soyuz three modules diagram with utility, landing, and instrument modules.
Credits: ESA

Now we enter the restricted club that contains the capsules in use right now in the various spaceports, we have already met the Soyuz, and they join her; the Shenzhou, the , and the New Sheppard (although the latter is only part of the suborbital flight)

The Shenzhou launched in 1999 with the first unmanned flight) is a licensed copy of the Soyuz, built with the same concept as the three modules but with slightly larger dimensions than the Soviet capsule.

As for Dragon 2 instead, we could easily write a trilogy in five parts (culture quote) as well as its importance on the political and economic scenario of Space Industries. Let’s go in order, it is the first capsule to be designed, built, and launched by a private, non-governmental agency, it can hold up to seven, SEVEN astronauts and legends tell that it is even equipped with a bathroom (a great luxury for orbital travel) equipped with a full glass cockpit all in touchscreen mounts the most advanced on-board systems ever. Among the peculiar features of this capsule, we can find four pairs of SuperDraco engines on the sides of the capsule capable of violently tearing the dragon from the rocket in case of problems, one of the most spectacular Escape systems ever built. the first historic launch on May 30, 2020, marking the first crewed launch to the International Space Station from U.S. soil since STS-135 in July 2011. 

Dragon 2 near the ISS – Credits: Wikipedia

As for the New Sheppard, instead, you can not properly call it a space capsule as it is designed to reach “only” the sub-orbital flight, more precisely, we are talking about a  vertical-takeoff, vertical-landing (VTVL) vehicle, it extreme importance derives from its HUGE internal volume easily hosting seven occupants and built purely for tourist reasons, in fact, the Blue Origins on 20  July 2021 marked a milestone for space tourism with the first flight with humans of this small, large capsule.

For decades the idea of flying in a tin can has always fascinated the human race, mentioned in novels, films, and songs with the famous Major Tom by David Bowie in Space oddity, history teaches us so much, and even more shows us the importance of innovations, the courage to dare and the beauty of dreams.

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Federico Coppola

Federico Coppola

Graduated in history from Federico II University in Naples, passionate about space, writing, and with an incurable dream of flying up through the clouds to reach the stars.
Admin of the Instagram page Italian_space_meme

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