Until the revolution: the problem of reusable rocket SpaceX

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The track “Earth — Moon”: how Russia will develop space in the XXI century 12 APR 2016, 16:08

Rocket somewhat similar to cars and other modern equipment: manufacturer of the new device is often much more profitable than repair the old

Private us company SpaceX for the first time managed to re-start stage of the Falcon 9 rocket into space and successfully land the returned item carrier on the platform in the Atlantic ocean. According to the forecast of experts, the technology of reusable devices should greatly reduce the cost of spaceflight, and the Elon Musk, CEO, called this event a revolution in the space industry. However, can we speak of revolution?

Experience the space Shuttle

Space exploration was originally a purely military objective, civilian purposes of the question at all. This industry still remains under tremendous influence of the ministries of defense and each state wants its own launch vehicles. Among the leaders in the number of launches Russia, USA and China, they have an average of more than 20 launches per year. More than five launches, the Europeans and India (India in the recent years have seen very strong growth). Less than five launches Japan, Israel, North Korea and Iran. The last couple of decades begins to grow, the share of commercial launches. And with the emergence of a new player — SpaceX Elon musk, the rally saying that the price of launches will be reduced, the world began the competition for the lowest cost of space flight.

Space wars: how the success of Elon musk hit “Roscosmos”

The Americans in this way have relied on the use of reusable spacecraft. Initially this approach was applied when designing the space Shuttle. In the American system the space Shuttle was a reusable space “Shuttle”, as well as two solid propellant booster. However, the death of “Challenger” and “Columbia” with their crews was a serious blow for the space reputation of the United States and for a time had suspended research in the field of creating a reusable spacecraft. Developments in this area nevertheless remained and was applied to the design of reusable rocket stages, landing which does not bear the risk of loss of passengers. So the re-launch of Falcon 9 is certainly the first implementation of the ideas, which in the USA is not the first decade.

Despite the obvious importance of this event, calling it by far a breakthrough is not. The idea of a reusable spacecraft inevitably requires diagnosis and repair, thus encountering what in science is called “theory of destruction”. In modern mechanics is still not fully formulated a holistic theory that describes the processes of destruction of materials, so calculate precisely, how to behave in one or another detail after the flight into space, virtually impossible. This can lead to unforeseen consequences, which, unfortunately, will be detected only at startup. In addition, a complete check of all components and assemblies of the apparatus, and especially their replacement, even partial, may result in considerable expenses. SpaceX itself its expenditures for these purposes do not disclose. Now officials say SpaceX on a 10% discount to partners who agree to reuse the first stages.

The production of most of the details are automated, and therefore to make them from scratch can be much cheaper than the mechanical interference and production of individual parts “individually”. The situation is about the same as with cars and, in fact, generally all modern appliances: the manufacture of the device is often much cheaper and more profitable than repair.

Chinese version

If the proposed apparatus will still be so reliable that the need for diagnostics and expensive repairs will really disappear, it will become really serious success. If the same tier will be able to fly into space at least twice, it will significantly reduce the cost of the flight. However, how to achieve this? To increase the reliability of the device by increasing safety, why naturally increases the weight of the entire apparatus, which automatically entails a reduction of the payload mass delivered into orbit. In addition to the return of the steps required to carry additional devices that also weigh a lot. Thus, the mass of the payload delivered into low orbit on a Falcon 9 rocket with a returned step, is 13 t, whereas without the return stage 22. Thus, the need for reusable margin kills the idea of the low cost of delivering cargo into orbit as the payload mass becomes too low.

In short, the idea of a reusable spacecraft, in spite of the excitement caused by the launch of the Falcon 9 carries some promise, but is fraught with a lot of unresolved contemporary science issues. An alternative way is cheapening the production of missiles through improved automation of the Assembly. Our competitor in this are not so much America and Elon Musk who are on their own, special way, as China, who chose the same “traditional” path as we. The cost of running their carrier rocket “Changzheng 5” comparable cost and with our “Proton-M” and American Falcon 9. And who in this race will be the first, only time will tell. In General opportunities to reduce the cost of launching multi-stage rockets are very limited and to achieve really significant savings is unlikely to succeed: it is not more than about percent. To radically reduce the cost of cargo delivery into orbit of the Earth need other solutions.

The authors ‘ point of view, articles which are published in the section “Opinions” may not coincide with ideas of editorial.

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