Average Reviews:
(More customer reviews)Are you looking to buy Spaceplanes: From Airport to Spaceport (Astronomers' Universe)? Here is the right place to find the great deals. we can offer discounts of up to 90% on Spaceplanes: From Airport to Spaceport (Astronomers' Universe). Check out the link below:
>> Click Here to See Compare Prices and Get the Best Offers
Spaceplanes: From Airport to Spaceport (Astronomers' Universe) ReviewThe writer of this slim volume wants to convince you that a spaceplane is the way to go, not just for earth to orbit, but interplanetary space as well.He correctly points out that current space launch technologies, whether dumb boosters or primitive space planes like teh Space Shuttle are costly, and very unsafe compared to commercial air transport. Costs are identified as being high due to poor reusability and few launches. Similarly, launching new hardware infrequently is not the way to improve reliability. From this he believes that only when launches are frequent and the vehicles reusable, will prices fall to sustainable levels. So far so good.
What will sustain high launch rates? Space tourism. This will generate a self reinforcing demand for higher volume and hence lower prices. Of course there are no operating SSTO spaceplanes today and they are very far off as well. Almost all require mixed cycle engines to improve their mass ratios. So far all very conventional thinking, even if dumb boosters are the current best way to deliver large payloads to orbit and beyond.
However the author strays off into fantasy when he then suggests that spaceplanes should become the interplanetary ships as well. We are presented with the idea that the spaceplane should be the vehicle for a trip around the moon. Now I know that I have difficulty staying on an aircraft for a few hours and a day is extremely uncomfortable. Now imagine seven days in possibly weightless conditions in a cramped cabin. And that is even before the radiation exposure. If you are dedicated enough to endure all that, what about his proposal for a multi-month mars trip in similar conditions? The author's logic is that the single vehicle is the reliable, safe way to go and that it's wings are needed to reduce propellant costs for reentry and that it's tanks could act as cargo containers for propellant to either the moon or back for refueling.
This is where his logic breaks down. It makes far more sense to have a reusable, dedicated space ship for interplanetary travel. This ship only needs fuel for changing orbits, not for launch, and can be large and protective of the passengers.
My sense is that the author sees all travel through the lens of commercial air travel, but fails to see that off world trips are more like sea voyages. If if are going to take a cruise that takes months, would you prefer to have the freedom of a big ship or be in the passenger cabin of an aircraft?
As to content, it is generally quite lightweight, and there is a lot of repetition between the chapters. The last chapter is a review of many of the private space companies paper spaceplanes. It is already outdated with claims that commercial operations will start in 2009, 2010. Virgin Galactic may not even start suborbital trips until 2014. Orbital trips are still the preserve of missile technology, with Boeing throwing its hat in the ring just this week.
Perhaps spaceplanes are really like the small airplanes of yesteryear, full of potential, but still unable to cross long distances and oceans like ships and airships. Unlike those times, we already have a good idea of the energies involved to reach orbit and the methods to achieve this. Air breathing, combined cycle spaceplanes might not be enough to achieve the goal.
Spaceplanes are a very elegant idea, and I really want to believe, but...Spaceplanes: From Airport to Spaceport (Astronomers' Universe) Overview
Want to learn more information about Spaceplanes: From Airport to Spaceport (Astronomers' Universe)?
>> Click Here to See All Customer Reviews & Ratings Now
0 comments:
Post a Comment