Space Exploration, Manned Orbiters

Survival in space requires more than just a sturdy ship suitable for the explorers of the past. Manned orbiting vehicles provide the safe, hospitable, and transportable environment found on the surface of the earth that humans need to survive the harsh reality of outer space. From capsules to shuttles to space stations, American, Soviet, and later Chinese space pioneers all took steps toward conquering the unknowns of space in the twentieth century.

Astronauts and cosmonauts alike certainly found the first generation of spacecraft designs cramped and uncomfortable. The designs differed, but their capacities in terms of room to stretch were equally limited. The Soviet Union succeeded in launching the first human into orbit aboard the Vostok spacecraft.

The spacecraft measured 7 meters long and included both a spherical reentry vehicle and an instrument module that was jettisoned as the craft began its descent back into the atmosphere. The re-entry vehicle, which housed the cosmonaut for the duration of the orbital flight, measured only 2.3 meters in diameter.

The spherical design of the re-entry vehicle allowed for even distribution of heat across its surface as it entered the atmosphere. Because the Soviets landed their craft on land instead of in the ocean as the Americans did, the cosmonaut ejected from Vostok at a safe altitude and parachuted down to the earth while Vostok pounded into the ground, only slowed by its own parachute.

The Americans’ first flights into orbit were aboard the Mercury capsule. Largely conical in shape, the bottom surface of Mercury was coated with an ablative heat shield for re-entry. Unlike Vostok, the entire orbiting vehicle returned to earth with the astronaut aboard; but it measured even smaller in size: just 3.3 meters long, including the retro rockets and 1.9 meters across at the heat shield’s widest point.

When the two space programs moved toward the moon and began carrying more than one person at a time, the Soviets’ concept changed few elements of its design. The idea of ejecting two or more cosmonauts for landing created a more challenging engineering problem than safely ejecting one. The Voskhod was the result.

Cosmonauts could land aboard Voskhod once engineers added a retro-rocket system to the vehicle; but given the very tight confines of the vehicle itself, when three cosmonauts were aboard, they could not wear spacesuits during the flight, leaving the crew unprotected from the dangers of depressurization. The Gemini capsule looked much like a larger version of Mercury, at a height of 7.7 meters and weighing 3800 kilograms, two and a half times Mercury’s weight. However, its modular component design and the addition of a docking mechanism made Gemini a more flexible and useful design than Mercury.

Part of the Gemini and Voskhod missions included spacewalks in preparation for moon flights. The Voskhod vehicle did not carry enough air to pressurize the entire capsule; so on March 18 1965, Aleksei Leonov used an airlock attached to the side of Voskhod for his spacewalk. With the smaller volume of the Gemini vehicle, Ed White was able to conduct his spacewalk on June 3 1965 without an airlock. James McDivitt stayed inside the Gemini 3 spacecraft wearing his own spacesuit while White floated just outside the hatch.

With the successes of Gemini—they included a spacewalk and a rendezvous with the Agena satellite—the American space program forged ahead with the flight of its newest conical spacecraft, Apollo. Similar to Voskhod, the Apollo spacecraft supported three astronauts. Wider than Voskhod, the Apollo spacecraft, measuring meters across at its widest point, allowed the seats to be placed side-by-side. Aboard Voshkod, technicians had to raise the middle seat by several inches to allow the cosmonauts’ shoulders to overlap. Apollo also produced a second manned orbiter, the lunar lander.

The lunar landing module, spider-like in appearance, represents the flimsiest of NASA’s spacecraft. Designed for the one-sixth gravity and no-atmosphere environment of the moon, the lunar lander stood on spindly legs and was covered by sharp angles. Unlike other manned space vehicles, it had a very limited purpose in terms of crew support. The crew would spend the majority of its flight to the moon and back in the Apollo command module.

En route to the moon, the command module pilot turned the command module 180 degrees and docked with the lunar lander. The commander and lunar module pilot only entered the lunar lander prior to their departure for the surface of the moon. More than any other spacecraft, the lunar lander served as a dinghy; the crew used it to get to and from its sailing vessel. No part of the lunar lander returned to earth.

Although the Soviets never achieved a manned lunar landing, they too designed a vehicle for the purpose, which would eventually fly. Sergei Korolev, the Chief Designer of the Soviet space program, and his team developed Soyuz with docking in mind. Like their previous vehicles, the basic structural design of Soyuz was a sphere.

Three modules—the instrument module, the orbital module, and the descent module—connected together to give the crew a ship with both laboratory and living spaces. In January 1969, Soyuz-4 and -5 docked together and transferred crew members for the first time, an achievement that the Americans would have to perform as well for the success of the moon program. The Soviet skills and technical achievements with docking procedures contributed to their next space success, the first space station, Salyut-1, launched on April 19, 1971.

The Soyuz and Apollo spacecrafts both saw service in the 1970s in the cooperative joint mission, the Apollo-Soyuz Test Project. The program brought American and Soviet space enthusiasts together for the first time in friendship instead of competition. However, the shuttle era of the 1980s saw a less intense but seemingly renewed race. In 1983, the U.S. launched the space shuttle Columbia, the first space truck.

Designed both as a rocket and a plane, the shuttle launched on the back of solid- and liquid-fuel engines, then landed like an airplane on a flat runway. In November 1988 the Soviets launched their shuttle Buran, almost identical to the American design; but the collapse of the Soviet Union in August 1991 left the Soviet space program without funds and little hope of a future. With the slow destruction of America’s own fleet of space shuttles, the shape of the world’s future manned space orbiter designs are again flexible.

The Chinese entered the boundaries of outer space in the late 1990s. Their vehicle bore a marked resemblance to the Soyuz descent module, an igloo-like capsule. In the years since the Soviets first put a man into orbit, the vehicles going into space have come full circle and the future of manned space orbiters remains to be seen.