Since NASA’s Apollo 17 mission landed on the Moon in December 1972 , almost 50 years ago, in the Taurus-Littrow Valley of the Moon, no human being has landed on the surface of our satellite . While several hundred astronauts have since visited space, none have left low Earth orbit . In that same time we have sent about a hundred unmanned missions to all the planets of the solar system and even to some comets and asteroids, with several of the launched probes currently traveling towards interstellar space, beyond the orbit of Pluto. .
Furthermore, compared to the hundreds of astronauts that have visited Earth’s orbit in recent decades, thousands of satellites have met a similar fate , reaching a wide variety of orbits around our planet. It is therefore evident that, for whatever reason, it is much more complicated to send humans into space than to send probes , satellites or even telescopes.
Going back, for example, to the beginning of the space race, the first artificial satellite was put into orbit on October 4, 1957 . This was Sputnik 1, from the Soviet Union. Just a month later, on November 7, the first orbital flight was launched with a living being on board, the famous dog Laika , who survived takeoff and successfully completed several orbits around the planet, but ended up dying from overheating. the capsule that contained it. However, it took almost four years, until 1961, for the first human being to reach Earth orbit . This was the Soviet Yuri Gagarin, who on April 12 of that year became the first human to reach Earth orbit . It is in fact this date that led the United Nations to declare April 12 (the day this article is published) as the international day of Manned Human Flight .
With this day, the United Nations intends to celebrate and remember the beginning of the human space age, reaffirming the important contribution that space sciences and technologies have had and have in the goals of sustainable development and in the benefit they can bring to the states. and its peoples, in addition to guaranteeing the objective that outer space be used solely for peaceful purposes .
Well, what made the Soviet Union take 4 years to take a human into space when it took (we could say) a month to take a living being? All the complexity can be summed up in one sad reality: those who designed the mission that took Laika into space (and their American counterparts, of course) didn’t care that the dog didn’t survive the mission . But any human being in orbit must survive not only takeoff and orbital maneuvers but also landing , one of the most delicate parts of any space mission. None of the thousands of satellites put into orbit have been designed to survive their eventual fall to Earth and only a handful of the interplanetary probes mentioned above have managed to land on their destination planet . But if we send people out there we want them to come back healthy and in one piece. This is the main limitation and the reason why taking a human to low Earth orbit is so expensive.
In fact, the main reason we haven’t sent humans to the Moon in almost five decades is not that we are incapable or that we have forgotten what we learned in the 1960s, but that the costs have become prohibitive . When the main objective of the United States was to win the space race and demonstrate technological superiority against the Soviet Union, the cost of the Apollo program was (apparently) justified, but when this objective was exceeded, this expense became meaningless. During the 1960s, NASA’s budget exceeded 4.4% of the GDP of the United States (1966), while in 2020 it did not reach 0.5% , which is about 9 times less budget.
Given these figures, it is not surprising that we have not returned to the Moon. And yet, NASA itself has plans to send astronauts to our satellite in just a few years, with the Artemis program. Thanks to the technological advances achieved in the last decades, they will be able to achieve it with a fraction of the budget of the Apollo program.
The development of reusable rockets , which has been led by the private sector with so much effort, will allow cheaper access to space and will facilitate our return to the Moon and our arrival to other bodies in the solar system. The space shuttle program, which completed more than 130 missions and was a testing ground for component reuse, ended up being more expensive than expected, costing more than $60,000 per kilogram carried into orbit, about 10 times more than the cost of the Saturn V rocket that was used during the Apollo missions. In the last decade, companies like SpaceX have managed to break the barrier of $5,000 per kg of cargo for the first time in history . Costs that this and other companies hope to reduce in the future. Hopefully it will shrink enough that it will be possible to start dreaming of a truly accessible Earth orbit.
REFERENCES:
United Nations International Human Spaceflight Day: https://www.un.org/es/observances/human-spaceflight-dayDollars per kg of different rockets: https://aerospace.csis.org/data/space-launch-to-low-earth-orbit-how-much-does-it-cost/NASA Budget: https://www.theguardian.com/news/datablog/2010/feb/01/nasa-budgets-us-spending-space-travel#data
