Space exploration has always been a captivating topic, and the scientific roles at NASA are no exception. From general physics to astronomy and space physics, there are 15 different types of scientists employed by NASA to work on various projects and missions. Many of the concepts for human exploration of the Moon and Mars include scientific research, and some even propose to use the Moon as an observation platform for astronomical and space physics studies. The launches of these missions require controlled explosions, and astronauts must slow down their vehicles with retrorockets and speed through the Earth's atmosphere with such force that heat shields are necessary to prevent the ship from melting.
For this reason, many scientists have argued that space travel with robotic vehicles is the best option. Despite this, manned spaceflight has been criticized for being extremely expensive in relation to its scientific performance. Two high-priority missions, Constellation-X and LISA, were proposed in the Decadal Survey Astronomy and Astrophysics in the New Millennium (2000). Constellation-X is an initiative to study the formation and evolution of black holes through space-based X-ray observations, while LISA is an initiative to detect gravitational radiation from the merger of supermassive black holes.
Both of these missions were greatly favored by connecting quarks with the cosmos. In addition to the United States and the Soviet Union, several other countries have succeeded in developing and operating scientific spaceships, allowing them to carry out their own scientific space missions. For example, Sputnik 2 orbited a dog, Laika, who died in space and was not recovered; in 1959, a Soviet probe transmitted the first photographs of the hidden face of the Moon. The importance of space exploration was highlighted in Connecting Quarks with the Cosmos and in a recent report from the Office of Science and Technology Policy (OSTP), Physics of the Universe (2000).
Most concepts for future steps in human space exploration have focused on missions to the Moon and Mars and their immediate surroundings. Wernher von Braun was appointed director of NASA's Marshall Space Flight Center and played a key role in designing future American launch vehicles. This was followed by NASA's Skylab space station, which was the first orbital laboratory where astronauts and scientists studied the Earth and the effects of spaceflight on the human body. In addition, many other countries have become involved in space activities through their scientists' participation in specific missions.
All amateur rocket builders were science fiction enthusiasts who believed that liquid-fuel rockets would make space flight possible.