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Topic Last Updated on 05-07-2024
WE’RE FALLING BEHIND!
At the dawn of the space age, it hardly occurred to anyone that, just half a century later, society would feel quite the opposite about space exploration: “Why do we need space, anyway? There are already a lot of problems on Earth that urgently need solutions!” To understand the level of enthusiasm and scale of humanity’s hopes at the time, we suggest looking back at the predictions of the legendary futurist and writer Arthur C. Clarke, made in 1999: in 2014, no orbital hotels were opened; in 2015, we still hadn’t invented technology for transmuting chemical elements; in 2020, we haven’t yet managed to launch an automated probe to Proxima Centauri, the nearest star to the Sun; and in 2021, it is unlikely that we will land on Mars. Given the past failures, don’t expect solar-powered interstellar aircraft by the 21st century’s end.
Sir Arthur Charles Clarke (1917–2008) was a British writer, scientist, and futurist. Together with Stanley Kubrick, he worked on creating the script for the cult film 2001: A Space Odyssey. Arthur C. Clarke along with Isaac Asimov and Robert A. Heinlein are known as the “Big Three” of the science fiction genre of English-language literature.
"I am sometimes asked who I would like to remain in the memory of people: a writer, an explorer of the underwater world, a space expert, or a popularizer of science. Most of all, I would like to be remembered as a writer — one who not only entertained readers but also, I hope, expanded their imaginations."
In reality, over the past six decades of the space age, there have been no qualitative leaps forward in space flight technology. The modern field of astronautics cannot boast of anything so impressive in terms of innovation and significance as, for example, the breakthrough of jet propulsion in aviation in the 1960s. In fact, so far we’ve only managed to more or less master near-Earth space by using developments from half a century ago.
Challenges of Long-Distance Space Travel
Long-distance flights are even worse. The planets closest to us, Mars and Venus, are extremely inhospitable. The budget for just one human flight to Mars, according to experts, starts at $400 billion. It’s difficult to imagine how much it would cost to transform an entire planet. Most importantly, is it even possible in the case of Mars? It is unlikely that humanity would be willing to pay such a price for the development of the “red planet.” It might be a different story, however, if there were a planet that was already habitable…
Look Further!
Or maybe you recall the very same Arthur C. Clarke’s Second Law? “The only way of discovering the limits of the possible is to venture a little way past them into the impossible.” Maybe we should try to engage humanity in a more ambitious task and venture beyond our tiny home, minuscule on the scale of the universe. How about our Solar System?
Clarke’s three laws
- When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
- The only way of discovering the limits of the possible is to venture a little way past them into the impossible
- Any sufficiently advanced technology is indistinguishable from magic.
In 1992, Aleksander Wolszczan and Dale Frail were the first to discover planets outside of our Solar System (they are called exoplanets, from the Greek exo, meaning “outside”). Two planets were found near a radio pulsar — a wildly rotating neutron star that spits out enormous energy and bears little resemblance to our Sun. Any object near such a star is obviously uninhabited.
Scientists then posed the question: do star systems have planets similar to the Sun? We didn’t have to wait long for an answer. In December 1995, the star 51 Pegasi in the constellation Pegasus, 50 light-years away, drew the attention of Swiss astrophysicists Michel Mayor and Didier Queloz. An object impacted it, causing a change in its movement. The explanation was found: a massive planet, similar to Jupiter, orbits the star, only it is twice as light and has a surface about 1800°F hotter. Since then, a real hunt for exoplanets has commenced. To date, the existence of more than 4,000 planets outside of our Solar System has been confirmed.
Space | Exploring Earth-Like Exoplanets
The next step is to search for planets that are as similar to Earth as possible. Scientists are looking for them in the so-called “Goldilocks zone” or circumstellar habitable zone, the main feature of which is the possibility of finding water in the liquid phase. Astrophysicist Wesley Traub, after analyzing data from the Kepler mission (a telescope that specializes in searching for exoplanets and was in orbit from 2009 to 2013), came to an interesting conclusion: 20 %–40 % of “dwarf” stars similar to the Sun have exoplanets in the habitable zone! This means that the probability of the existence of a very close relative to the Earth is quite high, if not the existence of a “twin” of our planet itself.
Considering Extraterrestrial Life and Development
Whether there is life there and what level of development it has reached is another question. This makes it possible to give interstellar travel a practical dimension and start thinking about how to get there.
Closed for Inventory
Modern chemical engines have allowed humankind to overcome the atmosphere’s transparent “armor.” For example, Voyager 1 moved over 13.5 billion miles from Earth, about 150 times the distance to the Sun, in nearly 43 years. This is impressive but microscopic on a universal scale. Its top speed of 38,000 mph (relative to the Sun) was achieved mainly through clever gravitational maneuvers rather than its engine.
Similarly, the fastest spacecraft, the Parker Solar Probe, reached 213,200 mph on November 5, 2018, surpassing the 1976 record of 156,500 mph set by Helios 2. By 2025, Parker is expected to achieve a speed of 430,000 mph relative to the Sun.
Such speeds are made possible by the powerful attraction of the Sun and the giant planets used for gravitational maneuvers. But isn’t it possible to achieve such speeds on our own? Unfortunately, no: modern chemical engines based on the exothermic reaction of fuel and an oxidizer compound cannot achieve this in principle. There is an insurmountable obstacle — the Tsiolkovsky rocket equation:
* Payload + vehicle structure + fuel
** Payload + vehicle structure
The Challenges of Increasing Rocket Speed
According to this formula, the speed of a rocket can be increased in two ways. The first is to take as much fuel as possible, even at the expense of the payload. What happens in practice? For example, if the mass of a spacecraft is assumed to be 16.5 t, then to accelerate it to the speed of “Parker” (≈213,000 mph), you would have to take all the oil reserves on the Earth (≈220 billion t) with you!
In other words, there is no real engineering capability that can achieve such high speeds with single-stage rockets. In addition, the Tsiolkovsky equation does not take into account the need to overcome the Earth’s gravitational pull — it is at this stage that modern rockets spend the majority of their fuel. Spacecraft are launched by multistage carriers, which on average account for 90 % of the total mass. Do not forget that the remaining 10 % includes not only the payload (satellite, manned ship, etc.), but also the structure of the craft itself — the hull, engines, tanks, pipes, and hundreds of thousands of parts without which it cannot work. So, the astronauts have to endure severe weight limitations and take into account literally every gram to meet the carefully-calculated percentages of the payload.
Exploring Alternative Fuels
But there is another variable in the Tsiolkovsky equation, the specific impulse, which can be considered with sufficient accuracy to be equal to the rate of expiration of the combustion products! Maybe we should just find better fuel? But even here, humanity has reached its limit. Currently, a “hydrogen-oxygen” pair is used, providing a speed of 10,000 mph. The most common combination of “kerosene-oxygen” is much slower — only 7,000 mph, and the “methane-oxygen” combination, promising in terms of efficiency and energy intensity of the steam, can only offer up 7,800 mph.
The main conclusion that follows from the Tsiolkovsky formula is that chemical rockets are unsuitable for serious travel in space. The fact that we continue to use them can be considered pure luck: if the mass of the Earth was just 40% greater, then chemical rocket engines could under no circumstances take us to near-Earth orbit, let alone on long-distance travel.
Predictions from Arthur C. Clarke.
The 21st century.
Didn’t come true
The first consumer device for energy production, absolutely clean and safe, based on principles of low-temperature nuclear reactions, will be released to the market. This means the end of the era of fuel extracted from minerals.
OYLA: There is no such device at the moment. It is still unclear how much time is left until the end of the fossil fuel era. Currently, 85 % of energy is generated from mineral extraction.
Internal combustion engines (ICE) in cars will be replaced with new devices for generating energy.
OYLA: Internal combustion engines are still used in 90 % of the world’s cars. Interestingly, the company Tesla, which produces electric cars, was founded in 2003.
The first human clone will be created.
OYLA: Therapeutic cloning is being developed to produce stem cells, but human cloning is prohibited in many countries.
The world’s last coal mine will shut down in India.
OYLA: In 2018, the last coal mine in Germany closed, but it is far from the last in the world. In 2019, the world produced about 8 billion t of coal.
NASA will create a new generation space telescope (the successor to Hubble).
OYLA: The James Webb Space Telescope was actually planned to be launched by 2007, but due to various problems it is expected to be launched in 2021.
All nuclear weapons will be destroyed.
OYLA: There are about 14,000 nuclear weapons in the world.
Generators powered by space energy will be developed. Power plants will begin to close; their time is up. Electrical networks will be dismantled.
OYLA: There are no such generators. We still generate power from power plants.
Construction of the Hilton Orbital Hotel will begin. Giant cargo bays of “shuttles” that previously fell to Earth and burned up in the atmosphere will be used as building materials.
OYLA: So far, the only place in space where a person can live is the International Space Station. But in 2021, the launch of the Aurora Station is planned — the first space hotel, which will begin to receive guests in 2022.
Technology for the transmutation of chemical elements will be developed, allowing us to control the structure of materials. Lead and copper, due to their greater utility than gold, will become twice as expensive as the “noblest metal.”
OYLA: There is no such technology yet. Gold is still more expensive than copper and lead.
Megawatt-hours will become the international unit of currency.
OYLA: There are about 180 different currencies in the world.
A huge meteorite will fall on the cap of the North Pole. Serious damage will be caused to the coast of Greenland and Canada. The “Spaceguard” project will be launched to identify and divert potentially dangerous comets and asteroids from Earth.
OYLA: In 2013, a meteorite fell near the city of Chelyabinsk (Russia). The damage was not catastrophic. There are various projects to detect space objects that are dangerous to the Earth, such as Pan-STARRS, ATLAS, NEAT, and others.
Artificial intelligence (AI) will reach the level of human intelligence. On Earth, two types of intelligence will coexist: biological and non-biological. Humanity will send spaceships with artificial intelligence to the nearest stars.
OYLA: It is too early to talk about the coexistence of two types of minds, although artificial intelligence is already used in scientific research, and it helps in the production of satellites, spacecraft, and processing photos from space.
