On October 4, 1957, for the first time, radio amateurs received the famous “Beep! Beep!” sound from orbit, marking the beginning of humanity’s ventures into space. However, despite the historical significance of this event, it was only the starting point of a long, long journey. In the second part on the history of astronautics, we talk about the space race between the superpowers, alternative space travel systems, and reusable spacecraft.
The Space Race and the Battle for the Moon
The first decades of the space era passed under the banner of the space race between the USSR and the United States, which made space another arena for their global competition. While it may be difficult to picture for modern audiences, in those years, literally every launch, every new space mission was considered from the point of global supremacy.
Initially, the USSR was the leader in the fields related to manned flights and launches into interplanetary space. The United States had an advantage in the “usable” aspects of space exploration: the first meteorological satellite, the first commercial communications satellite, the first spy satellite, and so on.
Soviet success in the early years of the space race was achieved mostly due to the noticeable advantages of the famous R-7 rocket and the carriers created on its basis. However, this advantage had a rather prosaic explanation. The R-7 was primarily created as an intercontinental ballistic missile designed to deliver nuclear bombs. In developing the carrier, the designers proceeded from the fact that the mass of the warhead would be a very impressive 5.5 tons. The “excess” carrying capacity incorporated in the project became the backbone for many of the USSR’s high-profile achievements in space.
This situation began to change after the United States announced its intention to send people to the moon by the end of the 1960s. Accomplishing that goal would require the use of much more powerful missiles than existing designs, and so they would need to be created from scratch. In fact, this ‘restart’ allowed America to re-enter the space race.
We will not dwell on the history of the moon race. We only note that to a certain extent, it repeated what had happened with the first satellite, Sputnik. This time, however, the United States focused all its efforts on achieving a specific goal. Meanwhile, the Soviet Union joined the lunar race with a noticeable delay, while dividing its resources into two separate projects: a decision that ultimately determined its defeat.
The end of the lunar race coincided with a significant decline in public interest in space. This was caused by a combination of different reasons. One of them was that the interplanetary missions launched to Mars and Venus convincingly showed that there was no life on those planets (at least in a complex form), and their surface conditions are absolutely hostile to humans. This dashed the hopes of many space romantics, who dreamt that in the near future humanity would create colonies on neighboring planets and establish contact with our alien ‘brothers.’
The increased understanding that space exploration is much more complex, dangerous, and expensive than was described by science-fiction authors also played a role in this diminished interest. In the end, high-profile successes in space exploration were accompanied by a number of equally high-profile disasters that claimed the lives of several spacecraft crews.
Alternative space travel systems
It is crucial to understand that over the past 60 years, in technological terms, the essence of space flight has seen little change. Modern rockets work according to the same principles as the rockets that sent Gagarin and Armstrong into space. Of course, different rockets can use different materials and different types of fuel and oxidants – but their core operating principles remain the same. Those can be reduced to one simple truth: from the point of view of efficiency (if we define it by the ratio of the payload placed into orbit and the launch mass), rockets are monstrously ineffective.
For example, let’s look at the legendary Saturn V, which took people to the moon and still holds the title of the most powerful carrier in history. It could put up to 140 tons of payload into low-earth orbit (LEO) in the form of the Apollo spacecraft with a lunar module and its third stage with fuel remnants. At the same time, the starting weight of the Saturn V was 3000 tons. Thus, the nominal efficiency of the rocket was less than 5%.
Of course, you can say that the Saturn V is the brainchild of the 1960s, and a lot has changed since then. In that case, let’s take a look at more modern rockets – for example, Firefly Alpha, which is made with extensive use of composite materials. Its launch weight is 54 tons, and its maximum carrying capacity for LEO is 1,000 kg. This translates to a conventional efficiency of only 1.8%. For Falcon Heavy, these figures are 1420 tons and 63.8 tons (4.5%), for the Falcon 9 – 549 tons and 22.8 tons (4.15%). But we are talking about low orbits. If the cargo needs to be sent “higher” (for example, to a geostationary orbit or to another planet), that carrying capacity will be reduced by several times. And at the same time, do not forget that rockets almost never fly fully loaded, and usually put less cargo into space than they theoretically can.
Even at the dawn of the space age, this ruthless arithmetic was obvious to engineers. Many of them believed that traditional chemical-fueled rockets were only “temporary” vehicles that would have to be used until something better and more efficient was created.
Particularly high hopes in this regard were pinned on atomic energy. One of the most daring projects of the beginning of the space age, called Orion, involved the use of small nuclear charges to accelerate a spacecraft.
The essence of the concept was as follows: the spacecraft is supplied with a powerful aft-mounted slab, which, during flight, ejects low-power nuclear charges that are detonated at a relatively short (up to 100 meters) distance. The charges are designed in such a way that the majority of the explosive synthesis, in the form of expanding plasma, is directed towards Orion’s tail. A reflective plate then absorbs this force and transfers it to the ship through a shock absorber system. The plate is protected from light flash, gamma ray, and high-temperature plasma damage via a coating of graphite grease, which has to be re-applied after each blast.
No matter how crazy this scheme sounds at first glance, it is feasible. Experiments using models have shown this explosive sort of flight – also known as impulse flight – can be sustainable. Experiments have also been carried out to validate the concept of a protective plate coating under real conditions. During a nuclear test at Enewetak Atoll, graphite-coated steel spheres were placed just 9 meters from the epicenter of the explosion. After testing, they were found intact, which proved that the proposed scheme for using graphite grease to protect the plate could be made to work.
The extremely high thrust and specific characteristics of impulse travel were supposed to provide the Orion with an efficiency that was literally unreachable by traditional rockets. According to Freeman Dyson, the famed physicist and mathematician, a ship with a launch mass of 4,000 tons could put cargo weighing 1,600 tons into orbit. Moreover, Orion could also be used for interstellar travel. According to Dyson’s estimates, a nuclear-pulse ship could accelerate to a maximum of 3.3% of light speed (modern calculations have readjusted this to 10% of light speed).
However, Orion never went beyond theoretical calculations and experiments. The Limited Test Ban Treaty in the Atmosphere, Outer Space and Under Water, signed in 1963, put an end to the further development of such ships.
Another interesting alternative to traditional rockets has been Nuclear thermal rockets (NTR). The heat generated by the nuclear reactor is used to heat a working fluid (usually hydrogen), which is then ejected through the nozzle. Although NTRs could not be compared in efficiency with the impulse-propelled Orion, they still had much higher thrust rates than conventional missiles. Thus, calculations have shown that if the upper stage of the Saturn V rocket is replaced with a nuclear rocket engine, this will increase the payload by 65% - 100%.
Both the USA and the USSR developed projects for creating rockets of this type and invested considerable funds in them. They were supposed to be used for missions into deep space, in particular flights to Mars, as well as for the creation of “tugs” designed to supply orbital stations and lunar bases.
However, despite a significant amount of theoretical work and a number of ground tests using prototype reactors, over time, all NTR projects were scrapped due to a combination of technical problems, the increased public fear of nuclear energy, and the reluctance of the superpowers to get involved in an expensive new space race. However, the results of the experiments and studies carried out have not gone anywhere and are simply waiting for their time. So who knows – maybe we’ll see revivals of this concept in the future.
Reusable space systems
The lunar race was truly a turning point in the history of the American space program. Thanks to an impressive financial infusion, NASA managed to achieve the most outstanding technological achievement in the history of mankind.
However, having won the battle for the moon, the American government turned out to be completely unprepared to continue supporting the space program in the same way. The country’s economy entered a difficult period, the Vietnam War required more and more resources, and generally, the public lost interest in space. This led to a large-scale reduction in space programs. Almost all projects that required significant financial investments were dismissed. In fact, a paradoxical situation occurred, where NASA’s triumph turned into the prospect of closing the entire manned space program. The organization urgently needed to offer something that could justify its continued existence.
The decision fell on a project that had been focused on designing a reusable cargo ship, initially meant to deliver people and goods to a large orbital station. NASA decided to “sell” the program to Congress (which is in charge of approving the US federal budget) under the guise of a commercial system capable of reaching self-sufficiency in the future – and even turning a profit. This was how the Space Shuttle program was born.
Initially, it was assumed that the system would be completely reusable. Engineers wanted to use a recoverable first stage to launch the shuttles, which, after separation, would land on an airfield like an airplane. It was a very elegant idea, but at the same time too complicated for those years. Soon, engineers had to abandon the idea and began to consider other options. Eventually, they settled on installing three rocket engines on the shuttle itself, and using a disposable external tank for fuel reserves.
It is worth mentioning that the experts, who were versed in the technical background of space travel, understood perfectly well that in reality, the Space Shuttle would likely never be profitable. Economic calculations carried out in the early 1970s showed that for the program to make back its cost, shuttles would need to make at least 30 flights a year, with a full load. At that time, there was no real need for so many flights But goals often justify means, and the shuttles main purpose was not to turn a theoretical profit, but the preservation of the American manned space program.
Despite all the efforts of NASA lobbyists, however, Congress was still not eager to fund the program. At some point, the fate of the Space Shuttle literally hung in the balance. To save the program, NASA turned to the Air Force for help. The military agreed to support the project, putting forward a number of requirements for the cargo compartment and the orbital capabilities of the spacecraft. NASA did not have the luxury of rejecting this offer, which culminated in a serious redesign of the vessel. By the end of that process, the shuttle had noticeably increased in size and weight, meaning that it would no longer be able to take off solely under its own power. Therefore, two side rocket boosters were added to its design. This is how the shuttles took on their final appearance.
Initially, it was assumed that the shuttle’s first flight would take place in the late 1970s. However, due to a number of technical difficulties, this was postponed several times. As a result, it wasn’t until 1981 that the winged spacecraft finally made it to the stars.
Despite their compromised nature, shuttles were revolutionary machines in their own way. They made it possible to carry out previously impossible space operations – orbital repairs, the return of failed satellites to Earth, the construction of complex space structures, the use of installations for moving in outer space, etc. Shuttles were also used to launch commercial cargo into orbit. NASA actively did this, striving to maximize the frequency of launches. The agency set a goal of conducting launches every two weeks. There were serious talks that in just a few years, shuttles would completely replace conventional single-use missiles.
However, everything carries a cost Technical trade-offs, savings on critical components, and the drive to increase launch frequencies to justify the ship’s existence — a combination of all of these factors resulted in the 1986 Challenger shuttle disaster.
After the Challenger, NASA had to make a number of major adjustments to the manned program. Due to changing safety standards, shuttles never flew at the same intensity again. In addition, a decision was made to stop using the shuttles for commercial cargo. At the same time, hopes that the shuttles could someday be profitable finally melted away, not to mention the plans to replace disposable missiles. At the very least, however, the shuttle program ensured that the American manned space program would continue.
After the end of the lunar race, the USSR found itself in a different situation than the United States. The Soviet manned program was not threatened with closure. The country instead refocused on the creation of long-term orbital stations, abandoning plans to organize expensive interplanetary expeditions. In this paradigm, the role of spacecraft, in fact, was reduced to a means of delivering crews to orbit and their subsequent return to Earth. For such a purpose, the already tested “Soyuz” rockets were quite enough.
But the Cold War forced certain adjustments. When learning of the Space Shuttle program, the Soviet military began to paint frightening pictures of winged ships dropping nuclear bombs on Moscow. It is difficult to say whether the generals really believed in such a scenario, or whether the exorbitant appetites of the military-industrial complex simply saw a source of extra funding – and the space program required more and more resources every year. Either way the country’s leadership was frightened by the threat of American space technology – real or imagined. It was decided to build a system “like the Americans”, without even trying to preliminarily determine what it would be used for.
What happened next was entirely predictable. Having spent resources comparable to the costs of the American lunar project, Soviet engineers created the Buran, which even surpassed the U.S. shuttles in some ways. However, what is the point of having a better ship if there is no practical use for it?
Shuttles were used to launch commercial and scientific cargo, repair and de-orbit failed satellites, and conduct research using the SpaceLab space laboratory. Buran was not suitable for any of these purposes. The Soviet Union did not carry out commercial launches. Most of the Soviet satellites had a very short lifespan and their orbital repair was not particularly expedient. To put cargo into orbit, the USSR had several good disposable carriers. Long-term orbital stations Salyut and Mir were available for scientific research. The country had Soyuz spacecraft to deliver people to these stations, and Progress and TKS unmanned spacecraft to supply them.
Thus, in the USSR, the “Buran” simply did not have a civilian or scientific application. As an illustration of its “uselessness”, one can cite only one fact: that despite the highly publicized test flight of Buran in 1988, at that time, it was completely unprepared for manned missions. Even if the program had not been closed, the first flight of the Soviet shuttle with a crew would have taken place no earlier than 1994.
In fact, “Buran” could only be of interest to the military in the context of the implementation of dubious projects such as the creation of combat orbital complexes and platforms for launching nuclear missiles. However, the Soviet economy, which had already begun to fail, could not support such programs. As a result, instead of a symmetrical response to the Americans, “Buran” actually became one of the last nails in the coffin of the USSR.
Yet, the superpower’s space race, and the countries of the European Union and the East that had later joined in space exploration, created our existing space infrastructure in its basic form, with all of its attendant problems and disadvantages. These existing systems and structures still allowed humanity to begin reaping the advantages of space.