THE NASA SPACE SHUTTLE: A VERY POOR CONCEPT THOUGH WELL ENGINEERED

Many years ago I read a very good book about the NASA Space Shuttle. This book was written after the first Space Shuttle blew up but before the second Space Shuttle broke up.

The book went into the whyfores and background into what went wrong with the space shuttle, how it promised so much, but ended up being very expensive and quite dangerous. One issue raised in the book was that NASA engineers not only were concerned with the O-Rings but were concerned with tiles damaging the heat shield. I have to admit that when reading the book I took the risks raised about tiles or foam damaging the heat shield as not likely to happen. Turns out the author of the book was correct, and I was wrong. An aside, if any reader can remind me of the title of this book, I would be most happy to include it here, however my memory fails me at this point

So what went wrong with the Space Shuttle? Firstly this is a disclaimer by a total non-expert, thus feel free to take what is written here with a grain of salt.

My main premise of this article is that the original concept for the NASA Space Shuttle was very poor. After the initial layout was decided upon, then the highly skilled engineers at NASA developed the vehicle that we all know. My main premise is that the engineers who built and designed the Space Shuttle had their hands tied and were asked to make the best of an extremely poor concept, with the subsequent disasters that we now all know about. I will attempt in some way to explain how and why this happened

For those of us old enough to remember, may be able to recall the promises made about the Space Shuttle before it started flying. Start with some dates, the first flight was in 1982, I was born in 1970. The promises of the Space Shuttle were;

• The Space Shuttle would fly every two weeks and be space taxi
• It would be cheaper than conventional rockets
• It would be reliable and reusable
• It would be safe and drama free
• It would usher in a new era of safe and low cost method of getting into space
• It would be used to assemble a space station

• The Space Shuttle was unreliable and did not fly regulary
• It was much more expensive than conventional rockets (cost was many mulitples of the cost of conventional rockets)
• It was a much less safe vehicle than the expendible rockets it replaced
• Two Space Shuttles failed, killing all on board
• It has been replaced by conventional rockets

For those that might be in some doubt as to whether the projected Space Shuttle was meant to reduce launch costs, then please read the following paragraph from Chapter six of the official NASA history

The goal we have set for ourselves is the reduction of the present costs of operating in space from the current figure of $1,000 a pound for a payload delivered in orbit by the Saturn V, down to a level of somewhere between $20 and $50 a pound. By so doing we can open up a whole new era of space exploration. Therefore, the challenge before this symposium and before all of us in the Air Force and NASA in the weeks and months ahead is to be sure that we can implement a system that is capable of doing just that.

A disclaimer and note to any NASA people that may read this

I would like to state that space flight is not easy, it is incredibly hard. Many of the engineers, workers, designers and scientists at Rockwell and NASA were and are incredibly bright and hard working. They were and are much smarter than I will ever be. All I am trying to do is write an opinion piece which explains in my view what went wrong, and to put it into some context

I do not claim that NASA engineers lacked skill or professionalism, my point is that the overall concept that they were asked to work on was poor from the outset, thus they were tasked with making the best of a poor lot

WHY THE FIRST SPACE SHUTTLE EXPLODED

Now it is common knowledge that the first Space Shuttle to explode (Challenger) did so because flame from the Soild Rocket Booster escaped through an O-Ring joint, and then burnt into the main fuel tank. Now at the time there was a lot of discussion as to why the O-rings failed. The reason was that the O-Rings being made of rubber were stiffer at cold temperatures and did not provide a good seal prior to lift off. Then one launch on a cold morning the ring was a bit too stiff to create a good seal.

What is less commonly asked is why there are O-Rings at all

Think about this, the Solid Rocket Booster (SRB) is just a metal tube filled with solid rocket propellant.
So why are there O-Rings in the first place? The answer is political.

The space shuttle program was not only about putting people into space, it was about distrubiting work across many states, so that there would be enough political support for the project to get it through congress. The SRBs were built in Utah by Thiokol corporation. The trouble was that the boosters were so large that they could not be transported in one piece to the Florida launch site. Thus the SRBs were built in sections and then assembled in Florida.

Now what happens next. One would think that the smart thing would have been to weld the pieces together once they arrived in Florida. This would elminate the potentially weak O-Rings. It appears that the downside of this approarch was that once the sections were joined together they could not be sent back to Utah for refurbishing. So now we ask, why did the SRBs have to be recyled/refurbished?

It appears the answer to this (well to the best of my knowledge) was that reusing the SRBs would be deemed more politically correct. It would have been cheaper and safer for the SRBs to be moved to the Florida launch pad, welded there, used once and then scrapped. However it was deemed that the space shuttle was to be a reusable vehicle, thus a political decision was made to make the SRBs reusable as well.

Next we ask ourselves why were there SRBs in the first place?

So why did NASA use SRBs which added cost, risk and complexity to the original Space Shuttle? The short answer was that they did it on the cheap. The longer answer is that the SRBs provided a cheap way (in terms of capital cost) to get the extra thrust required to get the vehicle into space, the downside was extra ongoing cost. The technical term for this decision is a false-economy. Thus they saved money on initial development costs by using SRBs, but at the price of additional costs for each subsequent launch

Now let us delve a bit more deeply in why there was a need for solid rocket boosters in the first place. Originally NASA would have preferred conventional boosters using liquid hyrdogen and liquid oxygen. These would have been safer and also provided less ongoing cost (less cost per launch), the downside was that these conventional boosters would have cost money to develop, and at the time NASA was very short of funds.

A final piece of the puzzle comes down to the size of the shuttle. The original plan was to have a 30ft cargo bay with a 20,000 pound payload. Instead NASA chose a 60ft cargo bay with a 40,000 pound payload, the end result was a larger and heavier shuttle than envisaged, which needed larger and more powerful engines. It should be noted that the Russian Space Shuttle, Buran, had conventional liquid fueled rocket boosters (not solid rocket boosters)

WHY THE SECOND SPACE SHUTTLE BROKE UP

The second space shuttle (Columbia) disintergrated because a piece of insulating foam from the main fuel tank broke off, was accelerated by the massive speeds the shuttle was flying at, banged into the wing of the Shuttle and caused a large hole in the leading edge of the wing. This hole was undected for all the time the shuttle was in orbit. On re-entry the super heated gasses around the space shuttle (caused by friction) got into the wing through this hole, weakening the wing so much that it eventually failed, causing the shuttle to break apart and hence kill all on board

In short having vulnerable foam forwards of the delicate structure and tiles of the Space Shuttle was a risk. Additionally it was a known risk, with many engineers worried about the impact of the foam breaking off and damaging the heat sheild and possibly the structure itself. It should be noted that in many many previous launches foam had broken off and damaged insulating tiles, it was a widely recognised problem and also widely reported at the time

COSTS: LETS TALK ABOUT MONEY

Now talking about money is actually harder than it fist sounds. For a start their is the issue of inflation, it being very difficult to compare 1970 dollars to the year 2010 dollars. Additionally different rockets have different payloads. Furthermore there is the issue of various orbits. The same rocket can deliver a much heavier payload to a Low Earth Orbit (LEO), than it can to a Geosynchronous Orbit (GEO)

Another factor to consider is reliability, if a laucher is cheaper, but is less reliable then the cost of payloads lost needs to be considered. Another factor to consider is technology. Technology improves over time, and hence cheaper and more efficient delivery systems can be developed over time. Another factor to consider is that a Space Shuttle mission that delivers a payload, can also provide the opportunity for the crew to perform scientific experiments in space, something not possible in unmanned expendable rockets

However I will attempt a rough comparison of costs, for sake of argument I will use 20 tonne payloads into Low Earth Orbit. Now most launchers deliver a lower payload that this, however it is the approximate payload of the NASA space shuttle, and there are a few rockets in play and that deliver an equivalent payload to the same orbit

The cost of the Shuttle per unit launch

Now the first figure given for the shuttle to deliver 24 tonnes into LEO is 450 million dollars. Another way to work out cost is to total up all the costs invloved in developing and running the shuttle project for several decades, and dividing that by the number of launches. Apparently Roger A. Pielke Jr has done this and come up with an individual launch cost of 1.5 billion dollars

So although there is some discrepancy between the two above figures, it does seem reasonable to assume that the cost for the NASA Space Shuttle to put approx 24 tonnes into orbit was between 450 million and 1500 million dollars

So how does this cost compare with other systems?

• The Delta IV Heavy American rocket can carry 22 tonnes to LEO for 170 million dollars
• The Soyuz rocket can carry 7.8 tonnes to LEO for 40 million dollars
• The Altas V rocket can carry 20 tonnes to LEO for 187 million dollars (newer technology)
• The Titan IV rocket could lift 21.7 tonnes to LEO for 350 million dollars (rocket now retired)
  
  
• The new Falcon 9 rocket is projected to carry 10 tonnes to LEO for 40 million dollars (though it has not done so as yet)
• The new Falcon 9 Heavy rocket is projected to carry 53 tonnes to LEO for 80 million dollars (though it has not done so as yet)
• The Russian Proton rocket can carry 20 tonnes to LEO for approx 100 million dollars
• The Ariane 5 European rocket can lift 21 tonnes to LEO for 220 million dollars

So we can see from the above figures that the Space Shuttle was at least three times more expensive that conventional rockets it was meant to replace. Now it is true that some of the above rockets utilise more modern technology and comparing the two systems may be unfair. However whichever way we look at it the Shuttle was much more expensive that the conventional rockets it was designed to replace.

Perhaps it is unfair to compare the Shuttle to newer technology like the Falcon rocket or the new Ukranian Angara series or rockets. However I do think it is fair to look backwards to what the Shuttle replaced, and that was the Saturn series of rockets. The Saturn V could lift 110 tonnes to LEO for 185 million dollars, and it had already been developed. Additionally there were smaller versions of the Saturn such as the Saturn 1 which could lift approx 19 tonnes to LEO for a relatively low cost. Whichever maths is used, the Shuttle was way more expensive than systems it replaced.

WHAT NASA REALLY WANTED TO DO: AND WHY THEY DID NOT DO IT

In the early 1970s, whilst the Space Shuttle was being developed, NASA had wanted a Shuttle, but the concept was radically different to what they ended up with.

NASA wanted a fully reusable two stage shuttle. The first stage would be a hypersonic reusable launch aircraft that would launch the shuttle into a high altitude and high speed. The two components would then separate. Then the the shuttle would go into space whilst the launch aircraft would then return to base and land on a runway, ready for its next mission. Sound confused? Well it turns out the Russians planned something similar, it was called Mig Spiral 50:50. Please have a look.

Please note that the ideal NASA proposal would have been very similar to the above concept, however it would have been two stage, not three stage as shown above in the Mig-Spiral 50:50 concept

Advantages of the proposed concept were:

• Low operating costs, due to mostly re-usable components (launch plane and shuttle)
• Ability to use equatorial orbits, thus gaining from the slingshot effect
• The shuttle is protected from debris impact.
• The ability to use better and safer insulation
• The launcher could be powered by conventional and cheaper jet engines

THE DEVELOPMENT TOWARDS THE SPACE SHUTTLE - PART 1

Although everyone knows what the Space Shuttle looks like now, it was not always meant to look like that. Instead there was a series of concepts over time that eventually led to the final concept. Even when the final concept (layout) was decided upon, there were four companies that bid for the contract to build the Space Shuttle, these were McDonnell Douglas, North American - Rockwell, Grumman and Lockheed. North American - Rockwell won.

Understanding the Context - what was happening at the time

To get an understanding on why the eventual decision was made, it is first essential to get a handle on what was happening at the time. Firstly America was in financial stress and money was tight. The Vietnam war was just finishing down and had cost a fortune. Additionally the second oil shock of 1973 had just hit, dramatically pushing up oil prices and hurting the American economy, thus money was tight. In brief NASA was very tight for money. Thus the huge amount of funds available in the 1960s to develop the Apollo program were simply not available to develop the Shuttle as they had wanted.

Now because money was short NASA had to make compromises, that is save money. One way of saving money was to reduce the capital cost of the Shuttle (initial development cost). The trouble with this is that by cutting costs at the beginning it leads to higher costs in the longer term. Hence lower initial costs lead to higher ongoing costs (costs per launch). The other compromise that NASA had to make was that to get political support for its funding it needed the support of the US Air Force. Thus changes were made to the size of the Shuttle cargo Bay (making it bigger to launch US spy satellites), and changing the wing design so that it could have a large cross-wind capability, that is the ability to land either side of where the orbit is taking you. This feature adds a military value, but at the expense of vehicle efficiency

Next lets talk about how lowering the capital cost increases ongoing costs. Examples of this saving of capital costs are

• Not fully developing the reusable engines the way they meant to be
• Not developing a fully reusable two stage shuttle system
• Using solid rocket boosters instead of liquid fueled boosters

Now why the interest in Space Planes, its not like NASA knew anything about them?

Well as it turns out NASA knew a huge amount about small reusable space planes by the early 1970s. They could go back and use their experience with the X-15, X-20 and X-24 rocketplanes. The star of these three planes was the X-15. The X-15 flew almost 200 flights, flew over 4,500mph (mach 6) and up to an altitude of 67 miles (this is practically space). All of these flights were in the 1960s.

The North American X-15 Rocketplane
The X-15 flew as high as 67 miles and at over 4,500 mph (mach 6+)
The X-15 flew almost 200 flights

The Boeing X-20 Dyna Soar.
It never flew, but was projected to fly at mach 26, cancelled in 1963

The Martin Marietta X-24B rocketplane. 'Only' flew to 1,164 mph.
Idea was to test getting aerodynamic lift from the vehicle body, referred to as lifting body technology
The X-24B flew 36 times

THE DEVELOPMENT TOWARDS THE SPACE SHUTTLE - PART 2

Now we know that NASA eventually ended up with the Shuttle as we know it, however there was a process of ideas that led to that point. The original idea was a fully reusable two stage shuttle. The first stage would be a hypersonic launch vehicle (speed approx mach 6) powered by both jet and rocket engines. The second stage would be a smaller fully resusable orbiter that could carry a four man crew (no females at that time) plus 10 tonnes of cargo in a 30ft cargo bay into orbit. There were many layouts proposed, here are just a few of them.

The original concept, note the straight wings

Some more ideas

An even later idea

An even later idea still

THE DEVELOPMENT TOWARDS THE SPACE SHUTTLE - PART 3

So now we have a reasonable idea of what NASA wanted to do with its projected Space Shuttle in the early 1970s, so where did it all go wrong?

The first thing to realise, as noted above was that NASA was short of money, it did not really have the money it really wanted to develop its shuttle the way it would have liked. It should be remembered that at this time NASA had just come off having massive funding allocations as part of the Apollo program and now that was starting to slow down. The second thing to realise, and this is very important, is that the new Shuttle that NASA wanted was an extremely difficult project to build. Lets just thik of this for a moment

Some of the technologies required for a fully reusable two stage launch system

• Hypersonic Stage separation - separating the two stages at speeds of Mach 6 or Mach 7
• Reusable rocket engines - until then all rocket engines had been use once, and then throw away
• Re-entry of large vehicles through the atmosphere - until then the largest vehicle had been the relatively small Apollo capsule
• Non ablative heat shields - until the shuttle heat sheilds had been designed to be used once, in essence they simply melted away during re-entry
  
  
• Higher re-entry temperatures - the larger the vehicle returning to earth, the hotter the temperature
• Control of a large aircraft though very high mach numbers - that is how do you control a large winged vehicle at mach 20
• Stability of a potentially unstable craft through re-entry, please remember at this time computers were in their infancy
• Development of jet engines that could be taken up to mach 6 (though rockets were used at this speed)
• And hundreds of more very advanced technologies that had to be developed

So what about taking their time and getting it right?

Now it can be seen that what NASA wanted to do was extremely challenging. So the obvious thing to do was to take their time, slowly develop the technologies required, and then in ten years or so they would be ready to start building their new shuttle. Now why was this path not taken? The reason is that NASA feared that a slow development process would risk having their funding cut sometime in the future, and then they would be left with no shuttle whatsoever. Thus NASA decided to follow a fast development schedule.

Now the final moves - how the eventual design was obtained, All this is explained in the final installment - PART 4, which can be found below. But first a brief interlude

DO YOU NEED A SHUTTLE TO GET INTO SPACE OR TO BUILD A SPACE STATION

It seems a simple question. At the time (early 1970s) it was assumed that reusable shuttles would be cheaper that use once, expendable rockets. But lets ask oursleves a few pretty simple questions. Firstly do we even need a shuttle at all?

To answer this question I might bring up two little technologies the first is Soyuz, and the second is the Salyut/MIR series of space stations.

The Soyuz rocket was developed in the early 1950s to get satellites and cosmonauts into space.

There have been over 1700 launches of the Soyuz rocket and it is still going strong.

Next lets look at building space stations in orbit without a shuttle, is is possible? The answer is yes. The Russians built a series of Salyut space stations and then the MIR space station in the 1970s and 1980s using their expendable rockets

Soyuz, 1700 launches and still going strong

MIR space station, built without a shuttle

THE RUSSIANS: GETTING IT WRONG JUST LIKE THE AMERICANS

Now we know that the Russians put the first satellite in space, the first man in space; Yuri Gagarin, conducted the first space walk, had a very good reliable rocket, had a good space capsule in Soyuz, and even had their own space station in Salyut. Now next they looked into reusable shuttles, their first attempt was the Mig:Spiral 50:50 as shown above. However this was cancelled, mainly due to cost and their having other alternatives such as the excellent Soyuz launch system. The funny thing is that though the Mig Spiral was officially cancelled Mikoyan kept working on it in secret (naughty, naughty).

In time they developed and built a prototype of the orbital vehicle. The next thing they did was to put a scaled down version of this orbital vehicle into space and see how it performed. The orbital vehicle was called the Mig-105

The Mig 105 orbital vehicle, a prototype was built and a scaled down version sent into space
Note the wings pivot up for high speed re-entry, and fold down for the final flight down to the runway

Now what happened next? Well something called Buran happened next.

It seems that in the early 1980s, the Russians saw that gleaming new and flashy NASA space shuttle. It seems that they said, well if they have one, then we want one too. Now is seems the thinking process here was more about national pride as opposed to thinking rationally. Be that as it may, the very highly skilled Russian engineers and scientists went on to develop their own version of the NASA Space Shuttle. It was called Buran.

Now Buran was superior to the NASA space shuttle. If I may explain why

• Buran could carry higher payloads into orbit
• Buran could be placed in a higher orbit
• Buran could stay in orbit much longer
• Buran could be flown unmanned if required
• Buran used safter liquid fueled rocket boosters as opposed to solid rocket boosters
• Buran could use its engines in descent, as opposed to the glider the NASA shuttle was

Buran the Russian space shuttle, far superior to NASAs version
Buran flew once in 1993, then the Soviet Union imploded.
Buran was a technical triumph, but conventional rockets could do the same job way cheaper
Buran never flew again

The Russians, one final chance to get it right

Now Buran was cancelled because existing rockets could do what Buran could do, but at a fraction of the cost. Additionally the Soviet Union was no more and the Russian economy was in freefall. Large expensive projects for national pride could no longer be justified. However it does not all end there.

Russia still had enormous skill in space technology and in aerospace technology. One company, Myasishchev (no I cant pronounce it either) came upon an idea, why not separate the vehicle to carry cosmonauts from the vehicle to carry payloads. This way the a small reusable space vehicle could be used to carry the cosmanauts, whilst payloads could use relatively simple, expendable upper stages. The advantage of this setup is that the new space vehicle could be much, much smaller. In addition, the vehicle together with its expendable booster could be carried under a very large aircraft.

Another factor to consider, was that with the breakup of the Soviet Union and the breakdown of the planned economy, individual companies were more able to pursue their own projects

Now as it happends Myasishchev knew a thing about making very large aircraft, for they had built large jet bombers for the Soviet air force. By joining two of their existing planes together they could dramatically lower the costs of developing the launch aircraft. All they needed next was a small enough rocket that they could carry under their 'catamaran' plane, and also to develop a small space plane.

Now as it happens Russia had a huge stock of existing rockets, additionally their rocket technology was superior to the Americans, for while the Americans spent most of their money developing their shuttle, the Russians spent their money improving on their rockets and developing and improving their rocket motors. A small aside Russian rocket motors are so much better than American rocket motors, that they are now used in some stages of American rockets.

Now one final thing was needed, and that was a space plane, well here again Myasishchev was able to follow on from the earlier work of Mikoyan and their Mig-105 space plane. The results can be seen below

The Myasishchev space plane concept, nice idea but Russia was out of money

And so it all ends.

• The Russians had the large planes
• They had the right idea
• They had the rockets
• They had the small space planes
• They had the technical skill
• Only one little problem, they had no money

THE DEVELOPMENT TOWARDS THE SPACE SHUTTLE - PART 4 - THE FINAL INSTALLMENT

The Space Shuttle - the final design is worked out

So by 1973 when the design for the Space Shuttle was being finalised, what was the situation at NASA?

• The US economy was in bad shape after the Vietnam war and recent oil shocks
• NASA was short of money it needed to develop a fully reusable two stage shuttle
• The Apollo program was coming to an end
• NASA was set upon an accelerated development schedule, because they feared a slow development schedule would result in loss of funding
  
  
• NASA needed US Air force support to get its shuttle through Congress
• NASA realised that the fully reusable two stage shuttle was enormously technically challenging
• NASA was looking for ways of cutting the initial cost of their shuttle or end up with nothing

So we know that in 1973 NASA was facing a lot of challenges. There was not the money available to develop the truly fully reusable two stage shuttle they wanted, but at the same time they realised that if they took their time to get it right, they risked getting their funding cut in later years and end up with nothing. At this time the US Airforce piped in, and put their foot down. The Air force said that if they wanted their support for the shuttle it should have a large cross-range capability and additionally a large payload bay that could carry large weights.

Now this is very significant for two reasons. A large cross-range capability means the ability to maneuver though the upper atmosphere left and right and land at airfields away from where it was lauched. In particular the Air force wanted the Shuttle to be able to take off and land in the US in a single orbit (remember the earth spins around, so you always end up further east on each orbit). This meant the Shuttle had to have a delta wing, not the straight wing NASA wanted. This meant a less efficient wing that gave greater weights. Next the large payload bay and payload capacity meant that the Shuttle had to be much bigger than what NASA wanted. A large shuttle means higher weights, larger engines, greater costs, higher re-entry temperatures.

Thus with their back to the wall, and the pressure to reduce development costs NASA Engineers came up with the idea of a single stage with an external fuel tank. Additionally they could use the 120 inch diameter solid rocket motors used in the Air Force Titan rocket to get the extra boost required. Now I am skipping quite a few steps here, but so summarise NASA was short of money and was looking at developing a Shuttle with the funds available

The layout early 1970s

• NASA new it was inefficient but they lacked the money to do it properly
• But it was to get worse the airforce demanded a big cargo bay
• End results a bigger, heavier, costly orbiter, and also having to add Solid Rocket Boosters

Now the big crunch, decision time with backs to the wall

It should be remembered that the whole concept of the Shuttle was to reduce launch costs, not increase launch costs

NASA realised that a large shuttle with a reusable heat shield required new technologies that were not then fully available. They also realised that the re-usable engines would have to run at much higher pressures than previous engines. The higher pressure engines were needed because they had to be light enough to get all the way into orbit, but also powerful enough to lift the Shuttle off the lauch pad fully loaded, and even further they had to be re-usable.

Now the smart thing to do with engine development is to slowly increase pressure over the development timeline. This way technology can be incrementally improved, and technologies that work well developed further, and technologies that dont work well discontinued. An accellerated development of very high pressure engines, together with re-usable engine technology resulted in huge technical risk

So now it was decision time for NASA. They were short of money, pushed into a corner by the airforce. They feared a slow and steady development program would leave them with nothing, so they made a decision to go ahead, even though they must have known they were undertaking something that would not achieve its aims. Perhaps we can explain it away with the thinking of the time, NASA has just succeeded with their Apollo program, they had the best people, so maybe they could get the Shuttle to work to. And in someways they did get it to work, but only at a much higher cost that the system that it replaced.

Could NASA have said no to a bad decision

This is a difficult question. NASA had been set on a Shuttle for years, and now it looked as though they were getting one even if they were not happy with the design. So what could they have done. It would have been very difficult, a very hard decision to make, however they could have made the following arguement. The Shuttle is designed to reduce costs, not increase costs. What is being proposed will be a backwards step, not a forwards step. Here is our alternate plan

• Put the Shuttle on hold for awhile until we improve our technology
• Maintain our manned space program with our fully developed Saturn I and Saturn V rockets
• Build a small permanent manned space station
• Work on a new generation of more efficient rocket motors for conventional rockets
• Start work on lightweight, high pressure, reliable and reusable rocket engines, and work on improving them over time
  
  
• Build on the work on the X-24 and X-15 into hypersonic space planes
• Start trialling and developing re-usable heat shield technology
• Develop computer software to control aircraft at very high mach numbers
• Concentrate on unmanned probes to investigate the planets
• In time develop a small Shuttle that just carried astronauts though no cargo

It has been calculated for less money than the US spent on their shuttle, NASA could have launched several Saturn V rockets per year. Even if they simply concentrated on launching the smaller Saturn I rockets with the occasional Saturn V, they could have done a lot with that capability. It should be noted that today some forty years since the last Saturn V the US still does not have a rocket that can launch anywhere near the payload of the Saturn V. Keeping the Saturn V, even it was just used occasionally, would have saved a lot of money compared to the Shuttle

An interesting, what if.

SO ARE SHUTTLES FINISHED FOR AMERICA?

The answer seems not quite. The idea still seems to carry sway, as the idea of a reusable space craft for carrying astronauts at first appears more logical than a use once then throw away system. The idea still carries on in the Boeing X-37 technology demonstator and the Dream Chaser crew launch vehicle. A little information can be found below

The Dream Chaser Spaceplane, now under development by Sierra Nevada corporation
Look familar? Is it just me or does this look a lot like the Mig 105 Spaceplane?





Mig Spiral 105 - Uncanny resemblence? Or is it just me?

The French Hermes Spaceplane of the early 1990s
Total weight was to be 19 tonnes, 3 astronauts and 3 tonnes payload
It appears that a little thing called money got in the way
Idea was to be launched by an Ariane V rocket from French Guiana

Next the Boeing X-37 technology demonstator
Look familar? Turn back the clock 50 years to find inspiration
Note the small size,
Note that a small aircraft is easier to get into orbit and endures lower re-entry temperatures

Last but not least - Space-X and their Falcon rockets

Now credit where credit is due. If we are going to dish the shuttle for being overly expensive, then we should give credit where it is due to Space-X. They seem to be doing a very good job in developing manned and unmanned rockets for a much lower cost.

How are they achieving this lower cost? It seems they are using smaller teams, being less buerecratic, using off the shelf modern technology, and also focusing on simple designs. Their unit cost per launch is a fraction of that of the large American aerospace companies, Lockeed Martin (Atlas series of rockets) and Boeing (Delta series of rockets). They (Space-X) have already have had successful launches and are now developing larger rockets

STRATOLAUNCH: BACK TO THE FUTURE

So now we have seen NASA try a reusable space vehicle, and then Russia try the same and then give up, so surely you might think why bother, I guess the answer comes down to the idea that 'in theory' a reusable space vehicle is cheaper. Now what if you simply decided for your reusable space launch system to go 'relatively' low tech, how would you go about that? It seems that the easiest thing to do would be to make the first stage a large subsonic aircraft. Better still use off the shelf commerical jet engines, landing gear and avionics wherever possible. Also when you think about it, as the launch aircraft does not have to take passengers, there is no need for it to be pressurised (with the exception of the small cockpit)

Now how else could you save money? With no need for a pressurised main cabin, there is no need for the main structure to be round, why not just build it rectangular, that would save money. Additionally as the launch vehicle is not going to be flying every day, there is no need to spend millions of dollars optimising the weight. It the aircraft is a fraction inefficient or a few tonnes overweight it does not really matter, all that matters is that it has the lift to get what you want into the sky. Now we have seen the Russians think about such a concept, Myasishchev, so that may provide some inspiration, something to get the mind thinking.

What next, now we need someone to fund it, someone like one of those billionaires who started Microsoft, they have a bit of dough hanging around. Next we need a low cost rocket to hang from our launch aircraft (Falcon 9 anyone), and lastly lets play a game and keep it all secret to near the very end. And what do we have: Statolaunch, coming to a spaceport near you soon (yes its real)

More information can be found at Stratolaunch.com LINK

Myasishchev Space plane: nice idea but Russians had no money

Sratolaunch Launch System: Yes its real, but I wonder it they will give any credit to the Russians for their idea

FURTHER READING AND LINKS

• By far the best and most detailed internet source on the development of the NASA Space Shuttle can be found on NASA's own website. The website can be found at this LINK
• An excellent article written by Richard Feynman, the renowned theoretical physicist, explaining the development of the Space Shuttle main engines and risk analysis at NASA can be found at this LINK
  
  
• Russian Space Web, excellent website relating to Russian spaceflight LINK
• A good Wikipedia arcticle dealing with criticisms of the NASA space shuttle can be found at this LINK
• A short article detailing criticisms of the NASA space Shuttle can be found HERE
• There was an excellent book regarding the Space Shuttle, written after Challenger exploded, but before Columbia exploded, however the title escapes me for now, it was an excellent read, if anyone can remind me of the title I would be most appreciative

A quick note about possible errors and further information

It could well be that some of the above figures could be a little out. If anyone feels strongly enough about this then please feel free to contact me and I am willing to make small changes where needed. For further understanding of how the NASA space shuttle was developed, I would strongly recommend reading the official NASA history, there are nine chapters there and I can recommend it as a thoroughly excellent read. Further information on rocket launch costs and payload weights can be found on the internet (wikipedia etc). I guess if you have the spare 100 million dollars lying around then no doubt you will spend a lot of time working out which rocket is the most suitable for you to launch your satellite, or no doubt you can afford to pay an expert to assist you with this

My intention was to provide a little bit of information over many topics, the anticipated readship is non-experts. For those interested in delving into the topic more fully there are a plethoria of books, websites, chatrooms, journals and documents to choose from.

Good luck

A final little note about copyright and all that. I wrote all the above text, it took me a lot of work. If by chance you want to use it, please contact me first, it should probably be OK for others to use it as long as the orginal source is noted, but please ask first.

Regards,
N. Peter Evans
November 2012