Overall Summary:
Wernher von Braun, a renowned rocket scientist, presents a detailed explanation of the challenges and opportunities in the conquest of outer space, focusing on the technical aspects of achieving Earth’s orbit and the implications of weightlessness in rocket ships. He also introduces the concept of using a centrifuge as a training tool for future space missions.

Challenges of Space Conquest:
Achieving Earth’s orbit requires a speed of approximately 18,000 miles per hour, which is three times faster than rockets can currently reach. Propellant improvements and weight reduction alone cannot achieve the necessary speed; multi-stage rockets are needed.

Three-Stage Rocket Design:
A three-stage rocket is depicted, with each stage providing a specific velocity increment. The first stage lifts off the ground and is jettisoned after one minute, reaching speeds of 3,600 to 4,000 miles per hour. The second stage adds 6,000 to 8,000 feet per second of velocity and is also jettisoned when exhausted. The third stage takes over and reaches the final orbital speed of 18,000 miles per hour, keeping the rocket in orbit.

Orbital Mechanics:
An orbit is established by balancing the gravitational pull of the Earth with the centrifugal force in a curved orbit. The higher the altitude, the slower the velocity required to maintain a stable orbit.

Winged Top Stage:
A winged top stage is proposed to allow the rocket to return to Earth, resembling an airplane-type stage. This stage would achieve the same orbital conditions as the non-winged version but could land safely due to its wings.

Elliptical Orbit and Atmospheric Drag:
The rocket enters an elliptical orbit, reaching an apogee whose altitude depends on the excess velocity over circular orbital speed. Over time, aerodynamic drag from the atmosphere gradually converts the elliptical orbit into a circular orbit 60 miles up. The ship then experiences atmospheric drag throughout its flight and eventually loses speed, requiring wings for landing.

Centrifuge for Crew Training:
Centrifuges are used to train crews for the harsh acceleration conditions experienced in rocket ships. A larger nacelle attached to the centrifuge can accommodate an entire crew for team training. The centrifuge can simulate erratic flight conditions to prepare crews for emergency measures.

Weightlessness in Rocket Ships:
Weightlessness occurs in rocket ships when the engines are cut off and the ship is coasting freely outside the atmosphere, not just after leaving Earth’s gravitational field. Weightlessness is caused by the absence of any force acting on the ship or its contents, resulting in a sensation of floating.

Weightlessness in Orbit:
Gravity is not only responsible for the force that pulls objects towards the Earth but also for the sensation of weight. In a weightless environment, such as a freely falling body or a spacecraft without propulsion, there are no differential forces between an object and its surroundings, resulting in a floating sensation.

Effects of Weightlessness on Human Physiology:
While humans can eat, drink, and even eat upside down in a horizontal position, the long-term effects of weightlessness on the human body are largely unknown. Medical experts believe that blood circulation may not be significantly affected, as the primary factor is the resistance of blood in the veins and arteries, not gravity.

Impact on the Sense of Equilibrium:
A critical concern in weightlessness is its potential impact on the sense of equilibrium. Small pebbles called otholites in the inner ears detect the direction of gravity by resting on hairs. In weightlessness, the otholites float freely, potentially leading to disorientation and symptoms similar to seasickness.

Artificial Gravity in Space Stations:
To mitigate the effects of weightlessness, a space station could be designed with a rotating wheel-shaped structure. By spinning the wheel, an artificial or synthetic gravity can be created in the rim, allowing people to experience a sense of weight. The rotation speed can be adjusted to simulate different levels of gravity, such as one g or one-third of g.

Construction of a Large Space Station in Orbit:
Building a large space station in orbit requires careful consideration of transportation and assembly techniques. The cargo holds of rocket ships are limited, necessitating the development of compact and foldable components. One proposed approach involves constructing the space station from multiple segments of rubber impregnated fiberglass or similar materials, which can be folded for transportation and assembled in orbit.

Inflatable Space Station:
The space station would be assembled in sections and inflated like a tire, providing structural rigidity and a breathable atmosphere. It would require systems for air replenishment, air conditioning, oxygen replenishment, and CO2 removal for extended stays.

Scientific and Research Capabilities:
The space station would house laboratories for various scientific studies, including biological and zoological life, outer space conditions, cosmic radiation, meteorological research, and astronomy. A powerful telescope near the station would enable clear observations of planets like Mars and Jupiter.

Military Applications:
The space station could potentially serve as a platform for bombing objects on the ground with unprecedented accuracy.

Deep Space Exploration:
The space station would be a crucial base for trips into deeper space, eliminating the need for aerodynamic drag and streamlining considerations. Once in orbit, low thrust ratings would suffice for breaking away and traveling further into space, as the centrifugal force in orbit already sustains the weight of the spacecraft.

Return From Orbit:
Wernher von Braun discusses the challenges of returning from orbit, emphasizing that aerodynamic deceleration is necessary to avoid excessive propellant use. Equipping the ship with wings allows for gliding and heat dissipation at high altitudes, resulting in a low landing speed of approximately 60 miles per hour.

Bombing from Space:
Von Braun explains the feasibility of bombing from a space satellite due to the ability to maintain line of sight with the missile throughout its flight. The missile’s elliptical orbit allows it to descend into the atmosphere while the space station remains overhead, enabling continuous tracking. The space station can guide the missile to its target, even moving targets, using radar and computer systems.

Communication in Outer Space:
Radio is the primary communication method between Earth and the space platform. A network of ground radio stations is required to maintain continuous communication as the space station moves over different parts of the Earth. Shortwave radio can easily penetrate the ionosphere, allowing for reliable communication.

Navigation in Space:
Close-range navigation can be done optically by determining the position and motion of the destination point against the background of stars. For longer distances, techniques like radar or optical bearings can be employed. Return maneuvers to Earth involve setting the right attitude for landing and timing it properly, using clocks, signals, and position measurements. For greater distances from Earth, star occultation measurements are effective.

Spaceship Lifespan and Protection:
Smaller meteors are more frequent and feared in space, while larger ones are rare. Thin armor of dural or steel can protect against smaller meteors. Meteor bombers, with a thin steel or dural skin spaced outside the hull, can vaporize meteors on impact and protect the ship’s surface. With such protection, a ship or space station can be protected for 5-10 years before a likely penetration.

Speeds in Space:
Rockets can theoretically achieve very high speeds in space, but practical limitations exist due to the amount of fuel required. Chemical fuel rockets can achieve speeds of approximately four miles per second in low orbit. Higher speeds are possible, but the ratio of fuel to payload becomes less favorable. The theoretical limit for speed is the speed of light, but this is far beyond current practical capabilities.