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To the moon, Alice!  Terry Drinkard

So far as I can tell, the first written description of a "gun" technology used for space exploration was in the classic Jules Verne novel, "From the Earth to the Moon," wherein the main characters use an enormous cannon located south of Tampa, Florida to launch a manned capsule to circumnavigate the moon. There are certain technical objections, of course, but Verne is one of the earliest, if not the earliest, writer to discuss the technical issues relevant to space flight in engineering terms. Like Arthur C. Clarke--the "inventor" of geosynchronous communications satellites, Verne was well ahead of his time.

Verne's classic science fiction look at circumnavigating the moon has a number of striking parallels to the Apollo 8 mission that really did circle our nearest neighbor in space. Granted, Verne didn't write about rockets, possibly because at that time, towards the end of the US Civil War (sometimes referred to here locally as The Great Unprovoked War of Northern Aggression), the rocket was an anemic little thing, militarily all but useless. Congreve's rockets--copied from the rockets of the Kingdom of Mysore (the British fought four wars there)--had limited performance and that performance had been outstripped by improvements in the design of guns, their projectiles, and the propellant powder. At the time, writing about rocket-based propulsion wouldn't have been at all believable. This state of affairs would change a century later.

Parallels

In his novel, Verne had to work through a number of serious technical issues relating to trans-lunar travel. He resolved almost all of them with what by our current standards was very limited information. His characters determined that the United States would be the country to make the first circum-lunar flight. That flight would be launched--fired, really--from southern Florida, and after passing through the lower atmosphere, would still retain enough velocity to escape the earth, some 11 km/second (6.6 miles/sec). This is actually quite true. The US did launch the first circum-lunar mission, Apollo 8, from southern Florida and it did need a bit more than 11 km/s of velocity.

More parallels

There are more parallels, though, and at the risk of getting too deep, lets look at some. The names jump right out at you. Verne's spacecraft was launched from a "Columbiad" cannon (the craft itself was apparently not named) and the name of Apollo 8's spacecraft was "Columbia." I thought that was cool.

Crews and materials

The Columbiad had a three person crew, Ardan, Barbicane, and Nicholl. The Apollo 8 also had a three person crew, Anders, Borman, and Lovell. The Columbiad spaceship was made primarily of aluminum alloys. This was a huge change for Verne's day, as the more usual material would have been a steel alloy of some kind; remember, this was the hey day of cast iron. The Apollo spacecraft was built almost entirely of aluminum alloys, itself somewhat surprising in this age of cheap titanium.

Time and recovery

The trip for the Columbiad lasted 242 hours 31 minutes. The Apollo 8 mission lasted 147 hours 1 minute. Both splashed down in the Pacific Ocean and both were recovered by vessels of the US Navy, the Susquehanna for the Columbiad, and the Hornet for the Columbia. I remember as a child watching that on the television. 

Verne's cannon

There would certainly have been some problems, obviously. The length of the cannon detailed in Verne's novel was a mere 900 feet. To achieve escape velocity plus the velocity that would be scrubbed off by passage through the lower atmosphere, would require an acceleration of some 22,000 gs. Yes, twenty two thousand gravities. That's a big number, and no amount of cushiony acceleration couches will preserve human life. That's a bit challenging even for inorganic electronics and mechanical systems.

Cost of reusable systems versus single-use

That very high level of acceleration which makes the unsuitable for launching humans is what makes them interesting for launching other payloads. Moreover, a gun launcher is actually quite a bit less expensive to operate than a rocket-based system. I think the development and acquisition costs are likely a push, but there is no doubt that cost-per-mission is much lower for the gun system than for the rocket system. Think about it for a moment. In a gun-launched system, everything except fuel and payload stays on the ground and is reused time and again. Rocket systems squander incredibly expensive single-use hardware at a prodigious rate. Only the soon-to-be-cancelled Space Shuttle brought any level of reusable hardware to the space launch industry, and it wasn't exactly cheap to operate either. 

Verneshot

Before we leave the topic of Jules Verne entirely, I found the term "Verneshot" (named after Jules Verne, of course). It is a term used in planetary geology to describe a hypothetical volcanic event, one that fires an enormous amount of material from deep within the planet on a suborbital trajectory. Apparently, it explains things like continental flood basalts and planar deformation features. Who knew?

Project HARP

The reason I brought up Jules Verne and his seminal novel is that I have been reading recently of Dr. G.V. Bull and his pioneering work on Project HARP. Dr. Bull was a Canadian scientist and engineer who discovered and developed a low-cost method of exploring the lower reaches of space. Dr. Bull used cannons to fire small space probes up to 180 kilometers above the earth, and with further development, could have gone higher, even to delivering small payloads into orbit. This amazed me when I first read of it. Keep in mind that Rutan's SpaceShipOne's highest flight was only 112 km. The edge of space is conventionally defined as 100 km in altitude.

Dr. G.V. Bull

Turns out that Dr. Bull was quite a controversial figure in his day, eventually embroiling himself in Middle Eastern politics with his gun developments, which led to his assassination in 1990 by the Israelis. Nevertheless, the part of his career from 1959 to 1969 is brilliant. Sadly, as in so much of space exploration, there were both military and political aspects to it that eventually compromised the program. Dr. Bull was apparently difficult for politicians and military people to work with. I feel his pain.

Dr. Bull worked through McGill University in Montreal to establish a new research program dubbed High Altitude Research Project (HARP) in cooperation with the US Army's Ballistic Research Laboratory. This was actually an off-shoot of his earlier research on anti-ballistic missile defense in the 1950s. He discovered that shooting an instrumented missile body out of a cannon gave as good results as a supersonic wind tunnel, but for a great deal less money. Very smart.

The two limbs of the HARP

Project HARP can be broken down into two major sub-programs. The first was a relatively small-bore cannon (five inches in diameter) that launched atmospheric radiosondes to an altitude of 76 km (250,000 ft) followed by a somewhat larger seven inch gun that could clear the 100 km mark, the edge of space. This "small-bore" program is interesting in that for a few hundred dollars per flight, any researcher could put up a probe to cover the full depth of the ozone layer, for example, as opposed to even a small sounding rocket that will cost a hundred thousand dollars per launch with nothing left for reuse. The Martlet projectiles (all of the HARP projectiles were named Marlet--old name for a martin--after the birds on the shield of McGill University's coat of arms) could be fitted with a parachute retrieval system, leaving only the propellant to be replaced. It would be hard to be more efficient than that.

Urban locations

One of Dr. Bull's points was that these systems could be installed and operated very close to built-up urban areas because they were very safe, especially as compared to a rocket. Sampling the atmosphere around cities could provide us with some very interesting data as we usually sample well away from built-up areas.

Big-bore cannons

The other major sub-program is the large bore sixteen inch diameter cannon which lofted payloads to 180 km. This system actually has the potential to put a payload into orbit. Surprisingly, that 180 km altitude was achieved without a rocket boost. Before the end of HARP, Dr. Bull had begun engineering a rocket-propelled payload, one that could achieve low earth orbit. This would have been a tremendous cost breakthrough. Unfortunately, the political aspects killed the program before that could be shown.

SHARP

More than two dozen years after HARP, John Hunter of the Lawrence Livermore National Laboratories began following in Dr. Bull's footsteps with the Super High Altitude Research Project (SHARP). This group of government scientists designed and built something called a "light gas gun" which uses an entirely new concept of combustion to propel payloads to incredible speeds. The HARP guns appear to have peaked in velocity a bit above 7,000 feet per second, which is amazingly fast, well into the hypersonic regime (HARP actually launched some SCRAMjet bodies for research purposes). The new SHARP light gas gun started at 10,000 ft/s and had the program continued, there were plans to achieve velocities well in excess of 20,000 ft/s. This is really very interesting stuff since orbital velocity is right around 34,000 ft/s.

On a personal note, when I was an engineer at Boeing in the early '90s, I was a member of the AIAA, and in fact, a minor officer of the Seattle chapter. We had what I recall as an awards dinner one evening and I was seated next to a really attractive young woman who was working on SHARP, but for whatever reason she couldn't explain the application for her research, or I wasn't smart enough to figure it out; probably the latter.

TekLaunch

John Hunter is continuing development of the gun-launched space vehicle with his company Quicklaunch which has morphed into TekLaunch; a potential provider of very low cost access to orbit. I understand he is still looking for investors. It appears to be technically pretty low risk, and it reeks of cool. 

Useful

With the ongoing withering of government support of civilian access to space, it seems to me that we on the civilian side would do well to find, develop, and utilize low-cost means to put something useful into orbit. One of the keys to establishing some sort of permanent, economically-viable presence in earth orbit is the ability to move materials from the ground to orbit cheaply, and gun-launched systems certainly look promising.


Note: Both the CVR and the FDR of Air France Flight 447 have been recovered, and even after two years under 12,000 feet of salt water, both memory modules were successfully read. We can expect a fuller report starting tomorrow, Friday 27th May, the BEA has announced.

Terry Drinkard is currently consulting on an aviation start-up. His interests and desire are being involved in cool developments around airplanes and in the aviation industry. Usually working as a contract heavy structures engineer, he has held positions with Boeing and Gulfstream Aerospace and has years of experience in the MRO world. Terry’s areas of specialty are aircraft design, development, manufacturing, maintenance, and modification; lean manufacturing; Six-sigma; worker-directed teams; project management; organization development and start-ups.

Terry welcomes your comments, questions or feedback. You may contact him via terry.drinkard@blueskynews.aero

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©BlueSky Business Aviation News | 26th May 2011 | Issue #127

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