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Unfulfilled hopes: what was planned and what happened in the program “Space Shuttle”


The other day I accidentally noticed that already five times in the comments I answered the question about the degree of success of the program “Space Shuttle”. Such regularity of questions requires a full-fledged article. In it, I will try to answer the questions:



The topic of reusable media is very voluminous, so in this article I specifically limit myself to just these questions.

What was planned?


The idea of ​​reusable ships occupied the minds of scientists and engineers in the United States since the 50s. On the one hand, it is a pity to smash the abandoned stages on the ground. On the other hand, the apparatus that combines the properties of an airplane and a spacecraft will be in line with the airplane philosophy, where reusability is natural. Various projects were born: X-20 Dyna Soar , Recoverable Orbital Launch System (later Aerospaceplane). In the sixties, this rather inconspicuous activity continued in the shadow of the Gemini and Apollo programs. In 1965, two years before the Saturn-V flight, a subcommittee on reusable launch vehicle technology was created under the Coordination Council for Aerospace Operations (in which the United States Air Force and NASA participated). The result of this work was a document published in 1966, which spoke of the need to overcome serious difficulties, but promised a bright future for work in near-earth orbit. The Air Force and NASA had a different vision of the system and different requirements, so instead of a single project, ideas of ships of different layouts and degrees of reusability were presented. After 1966, NASA began to think about creating an orbital station. Such a station implied the need to deliver a large amount of cargo into orbit, which, in turn, raised the question of the cost of such delivery. In December 1968, a working group was established, which became involved in the so-called. Integral Launch and Reentry Vehicle (ILRV). The report of this group was submitted in July 1969 and stated that the ILRV should be able to:

The report considered three classes of ships: a reusable ship “riding” on a one-time launch vehicle, a one-and-a-half ship (“half” stages are tanks or engines that are dropped in flight) and a two-stage ship, both of which are reusable.
In parallel, in February 1969, President Nixon created a working group whose task was to determine the direction of movement in space exploration. The result of the work of this group was the recommendation to create a reusable ship that could:

Initially, engineers moved in the direction of a two-stage fully reusable system: a large, winged manned ship bore a small, winged manned ship that was already entering orbit:

Such a combination was theoretically the cheapest to operate. However, the requirement of a large payload made the system too large (and, consequently, expensive). In addition, the military wanted the possibility of a horizontal maneuver of 3,000 km for landing at the launch site at the first orbit from the polar orbit , which limited engineering solutions (for example, straight wings became impossible).

Judging by the signature "high cross-range" (large horizontal maneuver), the military liked this picture
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The final layout was very dependent on the following requirements:

As a result, the final demands were made at the hearings in the White House and the Congress:


In the 1970 region, it turned out that the orbital station and the shuttle at the same time would not have enough money. And the station for which the shuttle was supposed to carry cargo, was canceled.
At the same time, unlimited optimism reigned in the engineering environment. Based on the operating experience of experimental rocket aircraft ( X-15 ), engineers predicted a decrease in the cost of a kilogram into orbit by two orders of magnitude (a hundred times). At the symposium devoted to the program “Space Shuttle”, which was held in October 1969, the “father” of the shuttle George Muller said:
“Our goal is to reduce the cost of a kilogram into orbit from $ 2,000 for Saturn-V to $ 40–100 per kilogram. This will open a new era of space exploration. The challenge for the coming weeks and months for this symposium, for the Air Force and NASA, is to ensure that we can do this. ”

B.E. Chertok in the fourth part of “Missiles and People” gives several other figures, but of the same order:
For various options on the basis of the Space Shuttle, it was predicted that the launch cost would be in the range of $ 90 to $ 330 per kilogram. Moreover, the second-generation Space Shuttle was supposed to reduce these figures to $ 33-66 per kilogram.

According to Muller’s calculations, the launch of the shuttle should cost $ 1-2.5 million (compare with $ 185 million for Saturn-V).
Also, quite serious economic calculations were carried out, which showed that in order to at least equal the cost of the Titan-III carrier rocket when directly comparing prices without discount , the shuttle must be launched 28 times a year. For fiscal year 1971, President Nixon allocated $ 125 million for the production of disposable launch vehicles, which accounted for 3.7% of the NASA budget. That is, if the shuttle had already been in 1971, it would have saved only 3.7 percent of the NASA budget. Nuclear physicist Ralph Lapp (Ralph Lapp) considered that for the period 1964-1971 the shuttle, if it had already been, would have saved 2.9% of the budget. Naturally, these numbers could not protect the shuttle, and NASA got on the slippery track of the game with numbers: "if an orbital station was built, and if it needed a supply mission every two weeks, then the shuttles would save a billion dollars a year." The idea was also advanced: “With such launching capabilities, the payloads will become cheaper, and there will be more of them than now, which will further increase the savings.” Only a combination of ideas “the shuttle will fly often and save money on every launch” and “new satellites for the shuttle will be cheaper than the existing ones for one-time missiles” could make the shuttle economically viable.

Economic calculations. Please note that if you remove the "new satellites" (the lower third of the table), the shuttles become uneconomical.

Economic calculations. We pay more now (left side) and win in the future (right shaded part).

In parallel, there were difficult political games with the participation of potential manufacturers, the Air Force, the government and NASA. For example, NASA lost to the management and budget office of the Executive Office of the President of the United States the battle for first-stage accelerators. NASA wanted boosters on the LRE, but because the boosters on the solid propellant rocket motors were cheaper to develop, the latter were chosen. The Air Force, which sought military manned programs with the X-20 and MOL, actually received the military shuttle missions free of charge in exchange for political support from NASA. Shuttle production was deliberately spread throughout the country between different companies for economic and political effect.
As a result of these complex maneuvers, the contract for the development of the Space Shuttle system was signed in the summer of 1972. The history of production and operation is beyond the scope of this article.

What did you get?


Now, when the program is completed, it is possible to say with sufficient accuracy which goals were achieved and which were not.

Goals achieved :
  1. Delivery of goods of various types (satellites, accelerating units, ISS segments).
  2. The ability to repair satellites in low Earth orbit.
  3. The possibility of returning satellites to Earth.
  4. Ability to send up to eight people.
  5. Implemented reusability.
  6. Implemented a fundamentally new layout of the spacecraft.
  7. The possibility of horizontal maneuver.
  8. Large cargo bay.
  9. The cost and development time met the deadlines promised by President Nixon in 1971.


Unmet goals and failures :
  1. Quality access to space. Instead of reducing the price per kilogram by two orders of magnitude, the Space Shuttle has become one of the most expensive means of delivering satellites into orbit.
  2. Quick preparation of shuttles between flights. Instead of the expected time of two weeks between flights, the shuttles prepared for launch for months. Before the Challenger disaster, the record between flights was 54 days, after Challenger - 88 days. For all the years of operation of the shuttle, they were launched on average 4.5 times a year instead of the minimum permissible according to calculations 28 times a year.
  3. Ease of maintenance. Selected technical solutions were very time consuming to maintain. The main engines required dismantling and a lot of time for service. Turbopump units of the engines of the first model required a complete reassembly and repair after each flight. The heat protection tiles were unique - each tile had its own tile. There are 35,000 tiles in total, and they can also be lost or damaged in flight.
  4. Replacing all disposable media. Shuttles never launched into polar orbits, which is needed mainly for reconnaissance satellites. Preparatory work was carried out, but they were stopped after the Challenger disaster.
  5. Reliable access to space. Four orbiters meant the shuttle crash was the loss of a quarter of the fleet. After the crash, the flights stopped for years. Also, the shuttles were notorious for the constant transfer of launches.
  6. The capacity of the shuttle was five tons below the required specifications (24.4 instead of 30)
  7. Greater horizontal maneuvering has never been used in reality due to the fact that the shuttle did not fly into polar orbits.
  8. The return of satellites from orbit stopped in 1996. Only five satellites were returned from orbit.
  9. Repair of satellites also turned out to be poorly demanded. In total, five satellites were repaired (although Hubble was served five times).
  10. Accepted engineering solutions had a negative impact on the reliability of the system. On takeoff and landing were areas without a chance to save the crew in an accident. Because of this, the Challenger died. The STS-9 mission almost ended in a catastrophe because of a fire in the tail section, which had already appeared on the runway. Had this fire happened a minute earlier, the shuttle would have fallen without a chance to save the crew.
  11. The fact that the shuttle always flew manned, put people at risk unnecessarily - there was enough automation for the routine launch of satellites.
  12. Due to the low intensity of operation, shuttles are morally outdated earlier than physically. In 2011, the Space Shuttle was a very rare example of operating the 80386 processor. Disposable media could be upgraded gradually with new series.
  13. The closure of the Space Shuttle program was superimposed on the abolition of the Constellation program, which led to the loss of independent access to space for many years, image losses and the need to buy space on the spacecraft of another country.
  14. New control systems and gauges allowed the launch of large satellites on disposable missiles.
  15. The shuttle keeps a sad anti-record among space systems by the number of people killed.


The Space Shuttle program gave the United States unique opportunities to work in space, but from the point of view of the difference “what they wanted - what they got” they have to conclude that it did not achieve its goals.

Why did this happen?

I specifically emphasize that in this paragraph I express my views, perhaps some of them are incorrect.
  1. Shuttles were the result of many compromises between the interests of several large organizations. Perhaps, if there was one person or a team of like-minded people who would have a clear vision of the system, it could have turned out better.
  2. The requirement of “being everything for everyone” and replacing all disposable rockets increased the cost and complexity of the system. Versatility in combining heterogeneous requirements leads to complexity, cost, unnecessary functionality and worse efficiency than specialization. It is easy to add an alarm clock to a mobile phone - speaker, clock, buttons and electronic components are already there. But a flying submarine will be more difficult and more expensive than a specialized aircraft and submarine.
  3. The complexity and cost of the system increases with size exponentially. Probably, a shuttle for 5-10 tons of payload (3-4 times less than realized) would be more successful. They could be built more, make part of the fleet unmanned, make a one-time module to increase the carrying capacity of rare, heavier missions.
  4. "Dizzy with success." Successful implementation of three programs of consistently increasing complexity could turn heads to engineers and managers. In fact, that manned the first launch without unmanned mining, that the lack of crew rescue systems at the launch / descent sites suggests some self-confidence.


Hey, what about the Buran?

Anticipating the inevitable comparisons, it is necessary to say a little about him. According to "Buran" there are no statistics of operation for many years. It turned out to be somewhat simpler with him - it was covered with fragments of a collapsed USSR, and it cannot be said that this program would have been successful. The first part of this program - “do as the Americans do” was done, and what would be next is unknown.
And for those who wish to arrange in the comments of the holivar “What is better?”, Please first give a definition of what is your “better”. Because both phrases “Buran has a greater supply of characteristic speed (delta-V) than the Space Shuttle” and “Shuttle does not reset expensive cruise engines with booster stage” are correct.

List of sources (excluding Wikipedia):
  1. Ray A. Williamson "Developing the Space Shuttle"
  2. TA Heppenheimer "The Space Shuttle Decision"
  3. The cost of a kilogram into orbit (for some reason, they were thrown out of the good table)
  4. Information about the satellites that repaired the shuttles.
  5. For the pictures, thanks to the group "Encyclopedia of Military Aviation" VK.


For navigation: posts on the tag "Facilitation of access to space"

Source: https://habr.com/ru/post/211891/

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