Persistence and Changes in SpaceX Plans

Last week, Ilon Mask spoke at the ISS R & D conference (Research and Development at the International Space Station). In more than an hour of conversation, he, answering questions, spoke about the various areas of space activity SpaceX. Some plans remained unchanged, but there were some interesting news in the speech.

Source: Saturn Felled Public

Number of starts
The plans for 2017 include another “about a dozen” launches. Since the last two years SpaceX was forced to take breaks due to accidents, it is still interesting how well they manage to scale up their production capabilities , and how many launches they can manage in 2017. In the list of plans for 2017 over the past two weeks, the number has already decreased from 25 to 24, and after all in January this year it was planned around 30 starts. Another “about a dozen” looks like a completely realizable number, because over the past six months the company has made 10 starts, while in January and February the starting activity was very low.

Inter-flight service
Musk confirmed plans to bring the period of inter-flight service of the first stage to 24 hours by the beginning of 2018. This is not new and has been voiced several times, but the importance of this is hard to underestimate - it is the cost, laboriousness and time spent on inter-flight service that determine the competitiveness of a reusable system. At the end of the year, a version of Falcon 9 Block 5 should appear, changes in which, apart from a small increase in engine thrust, will be aimed precisely at cheaper and simpler inter-flight maintenance. Even if, as a result, the preparation for the flight will not take a day, but a week (Musk is widely known for being too optimistic about the capabilities of his companies), it will still be a serious achievement.

Rescue fairing
According to Mask, the head fairing costs $ 5-6 million. This is somewhat unusual, given that the launch cost of the Falcon 9 is estimated at $ 62 million, the second step is "about 20% of the mission", i.e. 12.4 million, and the head fairing is a relatively simple piece. In the spring of this year, one half of the fairing was already able to be put on the water, which, however, can hardly be reused because of the impact of the water. In other sources, the construction was mentioned, which was jokingly called the “castle — an inflatable trampoline” for a soft landing of the fairing, and it will be interesting to see how it will look as a result. The announced dates are the rescue of the fairing at the end of the year, reuse, possibly next year.

Second Stage Reuse
At least for some missions, it will be possible to rescue and reuse the second stage, but this is a matter for a long time, because the main work in SpaceX is now on the manned Dragon 2. Considering that the second stage is in the same orbit at the moment of separation from the payload The task as a whole is difficult. It is relatively easy to select the rest of the fuel for braking at ~ 100 m / s for de-orbiting, but steps will require thermal protection in order to survive the descent in the atmosphere. To brake on ~ 4-6 km / s, so that heat protection is not needed, will require a huge supply of fuel.

Recycling Cargo Dragon
According to estimates of SpaceX, the repeated flight of the cargo "Dragon" cost almost as much as the launch of a new one. Musk believes that he could be even more expensive, because some expenses could not be taken into account. But for the future, Ilon remains optimistic and confident that subsequent repeated flights will cost much less, up to 50% of the new one. According to other sources , the next mission of the CRS-12 will fly a new ship, but it was also said that the production of the new “Dragons” of the first version was stopped, and starting with the CRS-13, the ships that have already flown will be launched.

The first launch of Falcon Heavy
Musk in every possible way tried to emphasize the complexity of the first flight of the Falcon Heavy. He even stated that he would consider the mission successful if the rocket falls far enough not to damage the launch facility. Alas, but, in spite of the image created all these years, they say, there is nothing easier than to take three identical steps, put them together and run, the reality turned out to be quite the opposite. 27 engines create triple vibration load, absolutely other forces act on the central unit, aerodynamic load changes. And not all in such conditions can be tested in advance on the ground. Mask noted that the central unit had to be redone so that it could withstand the changed and increased loads. A separation system was put on the side blocks, and before the actual flight it cannot be fully calculated how their separation will proceed. The area of ​​maximum velocity head (Max-Q) will also be a big challenge for the new design. Ilon said that the first launch will be a wonderful spectacle, and here he is absolutely right, regardless of the success of the flight.

Interplanetary Transport System
The reusable interplanetary transport system, the oddities of which were evident in the very first moments after the presentation in the fall of 2016, will decrease in size in order to earn money on near-earth orders. This decision is welcome, because the original version looked huge to the improbability. It will be fun, but not at all surprising if, as a result, ITS decreases ten times from the initially announced loading capacity of 500 tons to a low orbit and will carry bundles of satellites that distribute the Internet. Even if their number in reality is reduced to a thousand, instead of twelve thousand by today's plans, there will be work for such a rocket.

Changes in the landing system of Dragon 2
The biggest news was the official confirmation that in the manned version of Dragon 2 there will be no jet landing. On the initial rollers, the ship put forward the landing pillars and got on the engines, but for a long time there were rumors that this unusual way of landing would be replaced by more familiar parachutes. Musk spoke in the sense that the ship could so sit down, but they did not want to waste resources on convincing NASA of this, and, moreover, he revised the concept of landing vehicles on Mars. The fact is that the manned Dragon 2 was associated with the Martian version of Red Dragon, and both ships had to land on engines. The beautiful idea of ​​using the same engines as a rescue system and landing engines for the Earth and Mars initially looked utopian because of the difference in conditions. For example, the equilibrium speed to which the ship is decelerated due to the atmosphere is about three times higher than that of Earth for Mars, and if the Earth needs to extinguish about 300 m / s, then for Mars this value is about a kilometer per second.

Each method of landing a spacecraft has its advantages and disadvantages. Rocket engines make it possible to carry out an exact landing, which considerably facilitates the task of searching and evacuating, but since the engines are turned on for the last tens of meters, it is impossible to back them up, for example, with parachutes. And parachute systems, with all the disadvantages of low landing accuracy and the need to catch a ship from the sea or search in the steppe, are mastered, are very reliable and have backup systems in case of an accident. So, although it would be interesting to look at the Dragon 2 missile landing, this is not as bad news as it might seem.

Also, since Musk said that he no longer likes the Red Dragon Mars landing method (heat shield and engines on the sides), it is obvious that instead of Red Dragon there will be some other apparatus. For some, this can be unpleasant news, but, for example, the combined method of landing (parachutes and engines) combines the advantages of different designs, it is customary and successfully allowed to plant rather large vehicles on Mars.

New Direction: Moon
Surprisingly, for the first time, Musk lowered the intensity of aspiration to Mars, saying that the base on the moon would be a logical step before the flight of people to the red planet. It is known that, for example, today's director of the European Space Agency considers the Moon more promising, and more recently NASA presented the idea of ​​the Deep Space Gateway - a visited station in the lunar orbit. Perhaps we are witnessing a big turn in the response to the ongoing debate for many years - the Moon or Mars will be the next target for humanity.

I personally liked the answers to the last questions, even if they broke someone's dreams. There is a feeling that Mask began to communicate more with engineers and, at last, he realized the complexities of space technology. I would like to hope that in the future we will see fewer super-optimistic terms and unrealistic beautiful computer graphics, which will more than be compensated by a reduction in the news about the next transfer of a long-awaited mission.


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