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Canadian Team Plans Balloon-Aided X-Prize Entry
canning writes: "The National Post has an article briefly explaining the Canadian entry for the X Prize, the da Vinci project. The site includes visuals and a volunteer section, among others. The team plans to avoid almost the first half of the earth's atmosphere by launching the craft attached to a hot air balloon. The rocket will then fire it's engine and detach simultaneously. Interesting approach and believe it or not it gets better."
So this group has figured that in getting to 120km of altitude, the atmosphere is a big part, so a baloon can make the difference. Great, but what use is it in getting us closer to private space ventures, which is what the X prize was supposed to be about?
It's useful because the same technique lets you build much smaller orbital spacecraft.
To have enough delta-v to reach orbit with chemical fuels, your rocket has to be mostly fuel (between 90% and 95%, depending on the specific impulse of the fuel).
The strength-to-weight ratio of your rocket's frame gets better as your rocket gets smaller. This makes it much easier to build, say, a six-foot rocket that's 95% fuel than a 60-foot rocket that's 95% fuel.
Your rocket will lose energy as it plows through the atmosphere. As you make the rocket bigger, this becomes less of a problem. The balance point is where the cross-sectional mass of your rocket (mass per unit cross-sectional area) becomes greater than the cross-sectional mass of the column of air that it's plowing through.
At sea level, that's about 10 tons per square yard. Your rocket has to be about 30 feet high to reach the balance point, and would ideally be much larger. This will be a big, expensive rocket, and making it 95% fuel will be difficult.
Go up 20 miles or so, and you're above 90% of the atmosphere. The tradeoff point happens when your rocket is 3 feet long. Remember how I said building a 6-foot rocket that's 95% fuel is easier than building a 60-foot one? You could build something like this in a garage. All you need to have an orbit-capable mini-rocket is a way to bring the launch platform 20 miles into the air.
A mini-rocket would still be very commercially viable. Do a web search for "nanosat" and "picosat" to find projects that could be launched on a rocket this size.
A balloon is a great way to do this. Various types of powered aircraft might be able to make the trip too.
*That* is the benefit of this type of project - researching a practical launch platform that could be used for small, orbit-capable rockets.
Taking things one step at a time is critical for success.
We have a pretty clear plan of attack to take us to X-Prize level vehicles. There will be several intermediate vehicles to learn from along the way, but I am pretty confident that we can do it, and that I can pay for it. The regulatory approval is still uncertain. Things get much more questionable after that.
The next step would be using the X-Prize vehicle as a booster for a upper stage(s) that launch a microsat into orbit. That requires many times for dV, and the regulatory environment, telemetry, and logistics become a lot more challenging. This would get fairly expensive, because making a reusable upper stage(s) is a whole new level of problem, and you just can't test a lot of the systems without going all the way. Even on a shoestring, it could easily get to $100k for each attempt, after you factor everything in. Realistically, it will take a lot of attempts to learn everything you need to know. A lot of people will talk about how straightforward it is, but I have a healthy respect for the challenges. Smart money probably wouldn't bet on any "garage shop" getting to orbit, but it certainly isn't impossible.
After that, you could either work towards reusable upper stages, or scale everything up to the point you could try to orbit a passenger or a semi-useful LEO satellite.
Sure, if all that works out, I would love to make a moon shot, but that qualifies as day-dreaming, not planning. The idea that Dennis Wingo has floated recently about M class asteroids rich in platinum group metals possibly being able to have survived impact on the moon without vaporizing under some conditions is Very Very Interesting.
The extent of my "business planning" for the rockets is along the lines of "If you actually make something really, really cool, you will wind up making money on it somehow". Hopelessly naive? Possibly. We'll see. I hate being involved in business, so we would probably just partner with some of the existing companies interested in suborbital rides or sounding rocket business.
In the short term, watch for us getting a man off the ground in the upscaled lander frame within a couple months.
On topic: I think pretty highly of the DaVinci project, and I would say they are definitely one of the leading contenders. Brian Feeney talks about some technical issues on open mailing lists, which is a good sign. My biggest concern for them would be that, from my experience with JP Aerospace, getting two successful rockoon launches off within the 14 days required by the X-Prize is going to involve a good sized helping of luck.
John Carmack
The important thing is that Canada's finally using some of our precious few research dollars to do something that we should have been working on for quite some time. The benefits are clear and many:
The mission uses less fuel, since overcoming the first half can be done with a reusable balloon.
With the advantages of the balloon, it should be less of a problem as to where the launch site is, thus eliminating the need to ship everything to the deep south
We can finally paint a space vehicle red and white and have an onboard beer-cooler, potentially powered By the engines if we get the Kiwis onboard.
It saves on having to pay NASA for payload capacity to run our countless zero-G experiments
The X prize is potentially more than the entire gov't-funded budget.
Hell, this is exactly what I want to do with an Engineering degree!
- Relativistic? That's barely Newtonian!