That is a great question, and one I have thought about a lot recently.
Obviously, one of the largest constraints on cheap access to space exploration is the cost of a launch. However, I think you are looking for something more than that.
What it really comes down to is this: the cost of satellites is too high. For example, a typical satellite launched today can cost upwards of $200 million. This puts satellite technology in the hands of organizations (be they government or private) that can afford that price tag. Yes, the return on that investment can be huge. But that return is only available to organizations with deep pockets. My company, PBHspace, is trying to change that with the development of the
Q1 Spacecraft Bus.
But just why are satellites so expensive? Do they really need to cost $200+ million? I believe there are several contributors to that price tag, which I will outline and discuss for you (in no particular order):
First, most people who work on a satellite have very little perspective on the "big picture". They are a part of a Systems Engineering process, but they are only aware of their individual component. I wrote an
article to this effect, published in Space Times, which was widely received. Now, if all the engineers who worked on a satellite had an understanding of how their components worked toward the entire system, efficiency would be increased, decreasing cost. Too often an engineer learns various engineering principles in school, and then forgets them because they are not applicable to their job, and when it comes time to work on a large project - such as a spacecraft - they have little or no understanding of how their work makes the whole project move forward. By training engineers to work as a part of the system, as opposed to the subsystem or component, a spacecraft engineering company will reap the benefits of improved efficency and lower costs, which should be passed on to the customer.
Second, the cost of engineers is too high. For example, in the first eight years of my career, my salary nearly doubled, but my capabilities as an engineer had not really doubled, only the number of years mattered. Now, I want to make money as an engineer, and I am not looking for a pay cut, but is it necessary to pay an engineer with 10 to 15 years of experience $150k+ when you could pay a fresh out of school engineer a third of that to do (about) the same job? Again, I wrote an
article about innovation in the workplace, and whether it is necessary to pay for years of experience when a younger employee could do as well (or better, depending on the industry). There have been times in my career when I have looked back and said "I could have done this job at the beginning of my career, and it would have cost the company a lot less!" So, if a spacecraft engineering firm places less emphasis on years of experience, and more emphasis on the actual (innovative) capabilities of its engineers, there is a potential cost savings that would come with paying less for younger engineers who bring a lot more to the table than most firms give them credit for. Of course, experience should not be totally discounted, but engineering teams should be built with fewer experienced engineers and a larger proportion of less experienced engineers to reduce cost and, possibly, allow for more innovation. And those innovations wil benefit the engineering design, and the cost savings wil be passed on to the customer.
Third, there is a perception that satellites are expensive. Yes, they are highly complex feats of engineering that fly into a harsh environment and survive with a mission for years on end. But if you tell someone it is going to cost $200 million for their satellite, they will accept that. So the firm makes it cost $200 million for the satellite. But, and this is what PBHspace is aiming for, what if the same mission could be accomplished for $10 million? Would customers balk at that low price? Or would there be more customers?
Designing a spacecraft takes a lot. As I said, they are complex engineering marvels. But the methods of design have not really changed in the nearly 60 years that man has been orbiting artificial satellites. Things have gotten a lot more complex, yes, but the same engineering principles have held firm. And that is what needs to change. By ensuring that all members of the engineering team recognize not only the importance of their subsystem or component, but also the overall "big picture" of the engineering project, it will be possible to improve engineering efficiency and lower costs. By not relying so heavily on years of experience, and paying younger engineers with the same capabilities a lower salary, the engineering cost of the spacecraft will be reduced. And when costs are reduced, it no longer is necessary to say to the customer that the satellite will cost $200 million, and the overall perception that satellites need to cost so much can be eliminated.
Now, my discussion focussed on my perception of satellites, but the same applies to other spacecraft. There are several companies around the United States that are looking to develop spacecraft for space tourism or to supply the ISS with cargo and astronauts. There are, of course, differences between a communications satellite and a manned spacecraft, but the ideas outlined in this response still apply to some extent.
I hope I have been able to shed some light on how I perceive the costs of space exploration technology can be reduced. If you have any further questions, feel free to ask. And thank you, again, for your question.