Interesting thesis. I hope it's true but wonder if, instead, the "growth" is mostly marketing retaining names of families...
There's too few data points to extrapolate a trend from with 25-30 year intervals. Orbital rockets have existed for slightly less than 60 years, which is just about two intervals. A trend for smaller rockets also appears to be emerging, indirectly due to Moore's Law.Although the datapoints are limited and there is little to draw conclusions from, I have a hunch that the launch market is going to fragment between systems capable of supporting human spaceflight and those that need only carry satelites and small robots. We can't shrink people any time soon, but we can still shrink satelites quite a bit more, or pack more capabilities into the same size package. These can be launched on smaller, cheaper vehicles with lower safety margins. Human capable vehicles will probably continue to grow but this will taper off at some point, and instead the flight rate of these vehicles will go up - just like other forms of transport.
1) Rocket will on average continue doubling in capability every 25-35 years. 2) Their growth in capabilities will outpace their growth in mass due to greater efficiency.
Quote1) Rocket will on average continue doubling in capability every 25-35 years. 2) Their growth in capabilities will outpace their growth in mass due to greater efficiency.I don't see point 2 happening. Many rockets have mass fractions on the order of 95%, end engine efficiencies in the 95% range. Both leave little scope for improvement: we're near the limits of currently-known materials. We've gotten close to those limits over the past 30 years thanks to computers that allow us to calculate things like structural strength, so we can build a rocket that has the structural strength it needs, with very little margin. 30 years ago, those margins were much larger. So we've seen a lot of your #2 happening in the past decades, but this process is running into physical limits.
The question that continues to bug me is why this is happening. Are we seeing ever more capable rockets because of military requirements, the requirements of commercial customers, or because rocket makers are trying to gain an edge on their competitors?
The question that continues to bug me is why this is happening. Are we seeing ever more capable rockets because of military requirements, the requirements of commercial customers,
The computer world has long known of something called “Moore’s Law”. This “law” was first proposed by Intel co-founder Gordon Moore in 1965. It refers to an observation made by Moore, when he noticed that the number of transistors per square inch on integrated circuits had doubled every year since their invention. Although Moore’s Law today is no longer holding up as we near the limits of physics, computers are still continuing their exponential growth albeit at a slower rate. Much like with computers, the capabilities of rockets are also growing at an exponential rate, albeit a much slower exponential rate. It is something so common amongst families of orbital carrier rockets that you might call it “Wernher’s Law”. Instead of doubling in capability every 12-18 months, many rocket families are doubling in payload capability every 25-30 years. There are of course some exceptions, like the Proton rocket family. But even this family is being replaced by an even more potent successor family of rockets that will only grow in capabilities over time.
Quote from: Hyperion5 on 06/17/2017 09:52 pmThe question that continues to bug me is why this is happening. Are we seeing ever more capable rockets because of military requirements, the requirements of commercial customers, or because rocket makers are trying to gain an edge on their competitors?Payloads have long been the driver for launch vehicle upgrades. Usually, but not always, it is government payload requirements that drive launch vehicle size. - Ed Kyle