The "Space Age" will also be the "Rocket Age" since rockets will be the main means of traveling in space. There are various different kinds of rocket engine, but the traditional chemical rocket engine (in which a fuel and an oxidizer are mixed and the hot gases produced are ejected in the opposite direction to the direction of travel) will be the "work-horse" of life in space, like motor-car engines on Earth. To date most rocket engines are made to operate only once on an "expendable" vehicle, like a missile. So rocket operations are extremely expensive and small scale, and rocket engineering is still a small, specialized field.

In the Rocket Age, rocket engines and rocket vehicles will be "reusable" like all other forms of transportation. Railways, shipping lines, airlines etc don't use the word "reusable" because it's obvious. We don't talk about "reusable cars", "reusable buses", or "reusable aeroplanes". So it should and will be with space vehicles. So, far from being a small technical back-water, rocket engineering is still in its early days and has yet to see its heyday.

So we're looking forward to the era in which chemical rocket engines of many sizes and shapes are in everyday use - the "work-horses" of life in orbit. Without trying to predict the details such as what size and types of vehicles, what orbits, what types of engine and so on will be used, it is possible to foresee many of the broad outlines of the "rocket age". For example, rocket vehicles for launch, for in-orbit operations, and for longer trips such as to the Moon and back, will differ in many ways - though some may be multi-purpose, probably particularly at the early stages before the different markets are large enough to support more specialized vehicles. Specifically, vehicles used for launching from Earth to orbit and returning to Earth need to have aerodynamic and thermal protection which isn't needed for operations in space. Vehicles that operate only in space will have weird and wonderful shapes without concern for aerodynamics, but to have minimum mass among other constraints.

Another example is that although using LH2 (liquid hydrogen) / LOX (liquid oxygen) engines is in some respects more tricky than, say kerosene / LOX engines, it has the advantage that LH2 and LOX can be made by splitting water (H2O) using electricity. In orbit electricity can be generated from sunlight - so without using any fuel - and so wherever there's water you can make rocket fuel. This will be very useful in orbital operations, and we can envisage propellant stores comprising large insulated tanks for both LH2 and LOX, with insulated piping and pumps for recompressing gas to liquid, large water tanks, large solar panels for generating electricity, docks for receiving bulk supplies, exhangeable tanks, specialised delivery vehicles, pumps for supplying customer vehicles - whether passenger craft returning to Earth, small local orbit "taxis", cargo craft heading up to the Moon or further out, and others. The detailed design of these facilities to make them economical and competitive, raises loads of fascinating design issues. But with an orbital tourism business generating tens of $billions of turnover, it's easy to see that such business opportunities will exist. And from a business point of view they're far more promising, near-term and potentially profitable than plans for a possible government-financed base on Mars possibly 40 (?) years from now.

Overall, as rockets will be for life in orbit as motor-cars are on Earth, the rocket business is going to grow to have all the infrastructure that the car industry has on Earth: sales operations, hire firms, lease firms, orbital propellant bases, specialised repair shops, licensing, standard maintenance procedures, spare parts suppliers, second-hand stores, innumerable accessories, and scrap dealers. There'll even a whole range of leisure-related activities: races, rallies, collectors, antique dealers and restorers. There'll also be a corresponding range of new careers - pilots and stewardesses, mechanics, parts suppliers, and numerous business roles such as freight-forwarders, traffic-controllers, lease-financiers and insurance.

Some people support the development of more advanced launch technologies, such as rocket-sled launchers, scramjet engines, magnetic launchers running up a mountain-side, "orbital towers" and so on. But no-one has ever yet tried the simple chemical rocket approach. Why did the upstart DC-X caused such waves? Simply because no-one ever did it before. It could have been done (and was proposed) more than 30 years ago in the USA. And when it was finally done a few years ago it was not by NASA but by the Department of Defense, because they want cheap access to space.

The DC-X during one of its test flights

So let's try the simplest, oldest, but still untried approach of chemical rockets before we give up and look to complex new technologies that may or may not work, but in any eventuality will certainly take a long time to develop and cost a lot more money.

Then again, some people are against the whole idea at all - some of their most common objections are:

1. "Developing one or other of these vehicles would be prohibitively expensive - it would cost $10 billion".

   Cost estimates are controversial, but they're continually coming down. "Venture Star" is estimated at $6 billion. But even $10 billion would be less than half what government space agencies spend every single year!

   Even if it did cost that much (which is doubtful), if the public were given the choice they would certainly vote to give money for this rather than for much of what the space agencies currently use this money for. Spread over 5 years it would be less than 10% of their budgets - after which all the agencies' activities would cost a fraction of their present cost. Clearly a bargain.

2. "It will be impossible to license rocket powered vehicles for passenger transport".

   This is an easy one - they already have been! In the 1950s the RATO (rocket assisted take-off) version of the De Havilland Comet jet airliner was certified to carry passengers. Thus there's a legal precedent, and even space agency managers would probably agree that what has been done before can be done again!

A lot of technology has advanced enormously since the 1950s when many of today's rockets were designed - and many problems are now essentially solved - for example navigation. Remember how in the 1960s astronauts used to do training in case they landed in a desert or a snow field and no-one knew where they were? This is now impossible. You just need a $1000 box common in Tokyo taxis and you know where you are within a few meters anywhere in the world - and of course everyone else knows as well.

So when we talk of rockets at Space Future, we mean only "reusable" engines and vehicles. And we won't report much news about expendable rockets, because they're of little relevance to starting the Space Age. That depends on developing reusable vehicles - through test vehicles like DC-X and X-33 to Kankoh-maru, Pioneer Rocketplane, Roton, Spacecab, "X" Prize contenders, and others.

Interestingly, from a business point-of-view, for manufacturers there's still "everything to play for". For example, certain engines will become the mainstream engines favoured by many different rocket vehicle designers, leading to huge orders and continuing spare parts business. Which engines will they be? The winners in the Rocket Age will be made more like car-engines or aircraft engines than expendable rocket engines today - repeatedly reusable, with standard maintenance, overhaul and repair procedures. Almost no rocket-engine manufacturer has made significant steps in this direction yet. But like a lot of business, it's basically a race, and one thing we can be sure of is that those who don't even start won't win!