In the distant 70s engineers wanted to build spaceships of the future, which would be able to transport goods and people into orbit and then return safely to Earth again be in order. In part, they succeeded.
In the 90's space agency NASA led development of spacecraft that would function like an airplane. Agency pursued the goal to create a reusable spacecraft that would be effective and reliable, and has been profitable from the economic point of view - as opposed to the shuttle.
Why is expensive to run shuttles?
The structure of this device includes four components, only one of which was reusable, namely winged orbiter. Exterior extensive fuel tank is detached from the structure, and when the fuel has been completely consumed, and this occurred after 8 minutes of flight, he simply burned in the atmosphere. Located on the sides of the two booster also disconnects after 2 minutes of flight. After they landed in the ocean and went on further recovery. A little later, after the removal of missiles already filled with solid fuel. But all of these treatments have been very costly, as required special equipment, so it was easier to buy a disposable boosters to launch the space shuttle.
All these factors have raised the cost of launching the shuttle to huge numbers, but it is up to $ 400 million, making it extremely expensive vehicle. It should be noted that this amount is only one flight, not counting laboratory and on board satellites.For 40 years of the space age rockets single application in contrast to the space shuttle are cheap.
But by itself the idea of a single application seemed more wasteful because the car is comparable to throwing after each trip. Theoretically create multifunctional vehicle can be a long time. But due to the fact that produce materials that complement various designs, expensive, so their use is impractical.
Technology today on the verge of creating a reusable rocket
In recent years, several factors have changed, making the idea of creating a single-stage reusable launch more realistic. Since the inception of the shuttle key technologies have improved significantly. The rapid development of composite materials, ceramics and alloys possible to develop powerful heat shields and lightweight fuel tanks. In addition, the engines have become more reliable and easier. In addition to this problem, and heavy hydraulic systems were replaced by electro-mechanical flight control system. A modern computers and navigation system maintenance and improved navigation.
Technologies of this type are already being used in the construction of the liner Boeing-777 and F-22 bombers. All of these studies received their shoots in the 80s, when there was the development of an aerospace plane that would go into orbit.
Research
In the 90s engineers, supporting the use of reusable rockets, we were able to convince DARPA to conduct research, to make sure that single-stage rockets are more practical and cheaper to use. The first of such vehicles under the name Delta Clipper Experimental designed and built in the McDonnell Douglas Corporation.
Once the machine was ready, the team was ready to demonstrate to the public that DC-X is ready to fly.
The connection to the private sector
To reduce the cost of space flight need not so many operations. According to most experts, the cost reduction will help to attract new clients, among which there will be space tourists. Another part of the researchers believe that the costs may be reduced in the case where the pilot's seat in the government let private entrepreneurs.
From this point of view NASA fully agrees. In the 90 years of space agency announced that it wants to assist the private sector in the development of an experimental spacecraft X-33. The essence of this experiment was to show that space travel may be quite cost effective. In addition, the goal was to reduce the cost of the payload by 90 percent - to about three thousand dollars per kilogram.According to forecasts of NASA, reaching this goal, they could receive a reusable launch vehicles from the private segment, which will build and maintain the park.
However, MPH is not the main purpose, and served as a replacement for the shuttle. I need to replace the shuttle was not, how could they serve about 15 years, and with additional enhancements and up to 2030. The main goal of reusable launch vehicles were cost savings to start.
Tender wins NASA Lockheed Martin
Three major aerospace companies were interested in the development of X-33.Large version DC-X, DC-XA or Clipper Graham offered the company McDonnel Douglas. Improved vehicle on the basis of shuttle shuttle offered Corporation Rockwell International. But in July 1996 the space agency has decided to work with the company Lockheed Martin Corporation, based on the fact that under the plan the company was supposed to use a large number of technological innovations. In addition, the company promised a lot of interesting details in the development of reusable launch vehicles.
The essence of the plan was to Lockheed Martin rocket equipment klinovozdushnym reusable rocket engine. Usually used for this standard cluster conical rocket nozzle, as in the construct used several nozzles which are arranged along the edges of the rectangular wedges. In this case, we choke on each of the 7 engines on their own would be governed by an automatic control system. In the plan also included the construction of the "lifting body", in which the vehicle would have looked like a body with small wings. A huge area of the X-33 would unlock a new type of heat shields and efficiently distributes heat during re-entry.
Specifications X-33 are as follows: length of 20.4 meters, width 20.7 meters, speed of 17,000 kilometers per hour. It should be noted that this speed is not sufficient for reaching orbit. Starting devices planned for March 1999.
The device named VentureStar
His next concept called Lockheed Martin VentureStar, which was supposed to come out after the X-33. In general, the device was similar to the previous apparatus, but this was more than two times. Start facility was planned for 2004.
This ship was fully automated and included the crew. The onboard computer system itself would set the direction for each mission. A system of automatic control would regulate everything from the engine to the direction of the flight path.In this case, the people on the ship would be ordinary passengers. A capsule with a life-support system would be located in the cargo hold of the ship.
Unfortunately, the project was closed in 2001 due to lack of funding and the appearance of serious technical problems. Hope is now on SpaceX Elon Musk, who understands the importance of creating a reusable launch vehicle, which is engaged in SpaceX.
The development of launch vehicles by private companies was to reduce the burden of delivering astronauts to the International Space Station. In fact all that happened: space agency has signed contracts with companies such as Boeing, Lockheed Martin and SpaceX.
The space shuttle, which was first launched in 1981, despite the many constraints, was a very useful tool. With the help of the crew of the shuttle were launched military and commercial satellites, repaired the failed space equipment, conducted the research. With reusable launch vehicle in the future it will be easier to be able to access people in space. Vehicles of this kind will be an excellent way of expanding frontiers of knowledge.
