By the mid-20th century, the then superpowers (the United States and the Soviet Union) had made their first forays into space, signifying the beginning of the Space Age.
The main milestones are detailed below, and can be reviewed in greater detail on this link.
First laboratory in orbit
After both superpowers reached the Moon, they turned their attention towards Low Earth orbit. NASA built the Skylab space laboratory, which was active for roughly six months between May of 1973 and February of 1974; the USSR built the Salyut and Almaz series space stations, which were active from 1971 to 1986. The Salyut series stations came directly before the Mir space station, which was in orbit from 1986 to 1996.
The end of this rivalry led to a period of initially hesitant collaboration. As part of the Apollo-Soyuz Test Project, a Soviet and American space craft docked in orbit for the first time on July 17, 1975. To an extent, this project was the springboard for the agreement that led to the construction of the International Space Station (ISS). The United States and Russia are the main stakeholders, but the space station is also supported by other agencies: the European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA) and Canadian Space Agency (CSA).
Construction of International Space Station begins
In-orbit construction of the ISS began on November 20, 1998, when the station's first module, Zarya, was launched. The following month, the Unity module was launched and made the station inhabitable. However, a few years would pass before the ISS would become permanently manned.
At 9:21:03 (UTC) on November 2, 2000, the Soyuz TM-31 docked with the ISS. The former was manned by Yuri Gidzenko, Sergei Krikalev (for the second time) and William Shepherd. From then on, the ISS has always housed a crew.
Over time, the ISS has functioned as a laboratory, housing experiments in various scientific fields, due, above all, to the fact that it is a weightless (or zero-gravity) environment. It has also functioned as a testing ground for technology to be implemented in Earth as well as in space.
First probe sent to furthest planet in the solar system
At the same time that man took to space, many space probes and Earth observation satellites, starting with Sputnik, were launched. Artificial satellites for commercial purposes, whose technology frequently served a military purpose in the past, were also launched.
Over the past sixty years of the Space Age, we have been able to send probes to every planet in our solar system and many of their moons. Pluto was the last that we reached (2014), but by the time the new Horizons probe had arrived at its destination, Pluto was no longer classified as a planet. It would be remiss of us not to mention NASA’s Voyager probes that have charted a course for interstellar space though–depending on your perspective–they may have already arrived. Initially, these probes simply flew past their subjects, recording data as they went. Later, we were able to place them in orbit and ultimately land them on their subjects. In some instances, we have even been able to place vehicles on celestial bodies, such as the Soviet Lunokhod that explored the surface of the Moon between 1970 and 1973. We have also brought back samples from the Moon, space and asteroids, such as Itokawa. We have even placed a probe in a comet’s orbit (the ESA’s Rosetta probe) and a lander (Philae) on its surface.
However, we have not neglected our own planet. Many types of Earth observation satellites and scientific-satellite missions have revealed more about our home.
The robot Curiosity lands on Mars.
On August 6, 2012, NASA's Curiosity rover landed on Mars. In December 2018, NASA extended its initial, two-year mission indefinitely due to the vehicle’s success. The rover has been tasked with studying the climate and geology of Mars and determining if, at any point in the past, the planet possessed the conditions necessary for harboring microbial life, such as water. The rover is also measuring radiation levels on the surface in preparation for possible manned missions to Mars.
Six years after Curiosity landed, the rover has been able to work without a hitch, though its wheels have become more worn than initially expected. This may lead NASA to convert the rover into a fixed observation platform until 2020, when NASA will send a new rover that is based on Curiosity’s design. The
European Space Agency, in conjunction with Roscosmos, is also expected to send its first Mars rover in 2020. It is named Rosalind Franklin, in honor of the British scientist that helped discover the structure of DNA. However, none of this would have been possible had it not been for this technology’s predecessors. Sojourner, which landed on Mars on July 4, 1997, operated for 84 sols (Martian days) when it was only expected to last from 7 to, at best, 30 sols.
Then came Spirit and Opportunity. They landed on Mars in January of 2004 and operated until 2011 and 2018, respectively, far surpassing the initial estimate of 90 sols.
SpaceX launches the first Space 2.0 manned capsule.
SpaceX revolutionized the space launch market with the Falcon 9. It was the first rocket ever built with a reusable first stage, and it played a significant role in lowering launch prices. Now, the company's about to make history with the Crew Dragon manned capsules.
One of the capsules, which was unmanned, just returned from a test flight to the International Space Station. All the on-board systems were tested to prove that it can dock to the ISS and return automatically.
The capsule's life-support system was also tested; this functionality is not included aboard the Dragon cargo capsule, which regularly provides services to the ISS.
Given the highly successful results, everything is ready for the launch of the first manned Crew Dragon capsule to the ISS. All that is left is another test flight to check the escape system.
This will be the first manned capsule developed by a private company that goes into orbit and a great milestone in space exploration.