Going Up By Getting Small

A rough idea of scale; a Microlauncher on the left,
the Vanguard rocket on the right. Image by Robert Little

Back in 1989, I was given a task by my friend Dr. Mike Reynolds to build some models of the various launch vehicles, and as is typical with me, I decided to take it to the next level and build a few more. Two additional models I built were the Japanese Lambda 4S and the American Vanguard booster. Both were in 1/96, and what struck me the most were how small they really were. 

This fascination with small satellite boosters led to wondering if it would be possible for a small group of people, or maybe even just an individual, to build and launch their own satellite atop their own booster. The template for me was the Lambda 4S. It was slightly smaller than the Vanguard, and far simpler. A little imaginative planning on my part produced Project LAREDO.

While I no longer remember what LAREDO stood for (it was an acronym), much of it I do recall. It would have been a three stage solid fuel rocket that stood 35 feet (10.7 meters), and around 2 feet (60 cm) in diameter at the first stage. There would have been three solid boosters on the first stage, between each of the fins. Like the L-4S, the second stage would have also had a set of fins, and also relied upon a combination of ballistic and aerodynamics to guide its way into orbit.

Once I began work on how it was to be built, I started discovering how difficult it was going to be. While solid fuel rockets are far simpler to operate, their manufacturing isn't. The machinery required can become very pricey in a hurry. 

Liquid fuel rockets, while more complicated to operate, are much easier to build. There are also many other pluses to the design, such engines that can be throttled more effectively and shut down if needed. The complicated machinery needed to build large solid fuel rockets is negated. 

In the early 1990's, there were several groups on the West Coast that were experimenting with building liquid fuel rockets with the ultimate goal of putting an amateur satellite into orbit. Notable amongst them was the Pacific Rocket Society. During the first part of the 1990's, they were headed up by Charles Pooley, and they had that lofty goal of placing a very small payload into orbit. They managed a few tests during that time, demonstrating proof of concept. Charles Pooley is now working on what he calls "MicroLaunchers", and the goal of simply placing something in orbit can be seen as a stepping stone towards ventures even further afield. I caught up with Mr. Pooley on March 4th, 2014, with a few questions, as well expressing a few concerns of my own where CubeSats and other small satellite designs are concerned. 

Robert Little (RL) - It seems to me that many of the micro and CubeSat builders and enthusiasts haven't really given a lot of though on how to get their creations aloft (this isn't always necessarily the case, but seems perhaps a little too common). Certainly, there are the normal means, such as piggybacking on larger payloads, but then you are relying on that payload going into a similar orbit.
Charles Pooley (CP) - No, they don't give it any thought whatsoever. They assume that being a secondary payload is the only way to do it, and it is not. For one thing, it's not very cheap. The price ranges from $80,000 to $125,000 for a 1U launch, and nothing bigger than that.
(Note - 1U is the size of a standard CubeSat, 100mm square)
But the Microlauncher concept is far more that just CubeSats or small satellites. Long term plan is for true escape velocity for smaller payloads. Satellites by themselves aren't really useful. They don't help advance the exploration of space in anyway any more.
From the beginning, the premise was based on somewhat smaller escape velocity payloads. When I first worked this out in 1995, it was about 1 lbs (454 gram) payload, but since I have reduced it down to about 200 grams (7 oz). Liftoff weight including propellant will almost certainly be less than 200 kg (440 lbs), around 150 kg (330 lbs).
RL - So when you are saying "Microlauncher", you are truly meaning "micro launcher". Let's take a moment to talk about the launcher itself, since that's really my main area of interest here. Just how big (or small) would a typical Microlauncher be?
CP - Presently, we're looking at up to 10 inches (250 mm) in diameter and about 13 feet (4 meters) in length. 

Those dimensions are amazing. In this case, we're talking about a launch vehicle that is not much larger than some high power amateur rockets. To date, the smallest ground based satellite launcher has been the Lambda 4S, at around 54 feet (16.45 m). 

RL - So far, the smallest launch vehicles I've written about were the Japanese Lambda 4-S series. 

CP - They are mentioned in the book, that and the Vanguard. This isn't counting the thing carried by the F-15, the ASAT. It hasn't even been determined if one of those went into orbit. 

RL - I know that during the late 1950's and early 1960's the US Navy was conducting Project PILOT, which were air launched attempts utilizing F4D Skyrays and later F-4 Phantoms. They were small, but they never struck me as particularly practical, as not everyone has access to supersonic aircraft.

CP - Correct, and it hasn't even been considered that air launch is more expensive than ground launch. The costs of having additional propellant and rising from the ground is less than having and operating an airplane, I think. About the only thing that is practical with air launch is the ability to launch wherever you need to. 

For a long time, it seemed to me that an air launched rocket might offer some advantages. But after reading up on Project Pilot and the several attempts that were made, it seemed more of a pipe dream. The most successful air launch vehicle to date is Orbital Science's Pegasus, and it is truly a different class of launch vehicle. 

RL - As far as stability and guidance, what methods are you considering? Are we looking at gimballing, fins?

CP - For the upper stages, I'm thinking the method that (Robert H.) Goddard used to use, paddles in the exhaust. That method ought to work well in a vacuum, where the exhaust expands. The first stage will probably use a steerable engine. 

So while the Microlauncher concept may be small, it is in reality far from simple. It is hoped that this very small class of launchers could truly open up not just low Earth orbit, but delving deeper into space, with a variety of missions, including but not limited to lunar and deep space. As mentioned, the resulting probes would have to be very small, but as they say, once you're in orbit, you're halfway to anywhere. 

If you want to find out more about the Microlauncher concept, I recommend checking out his website, Microlaunchers. He has also co-authored a book on the subject with Ed LeBouthillier, "Microlaunchers: Technology for a New Space Age" 

Perhaps one day there will be tiny little armadas of miniature space probes cruising the Solar System. If so, we might have Charles Pooley and Microlaunchers to thank.