Getting to space takes a tremendous amount of energy. Sufficient fuel must be carried to generate the energy required. Oxidizer must also be carried unless atmospheric oxygen is used. Rockets, by definition, carry their own oxidizer, which often weighs as much as eight or more times the weight of the fuel itself. SA's ejector ramjets use inlets to capture atmospheric oxygen thus dramatically reducing the amount of propellant that must be carried. Moreover, the ejector ramjets are much more fuel-efficient as well, thus reducing the propellant (hydrogen) weight. Furthermore, SA's Reusable Launch Vehicles (RLV) employs an aerodynamic "horizontal" trajectory, using lift generated by its wings rather than brute force thrust from a rocket-powered vehicle to climb up to altitude. To better visualize this, picture a rocket that climbs vertically off a launch pad. The thrust must equal the weight just to "lift off" the ground. Only the thrust in excess of the weight of the rocket-propelled vehicle contributes to accelerating the vehicle upward, the rest goes solely into countering gravity. In contrast, the RLV uses wings to generate lift to counter gravity. Wings are much more efficient at generating lift to counter gravity than using thrust from a rocket. SA's aerodynamic configuration generates four pounds of lift for every pound of drag created even at high speeds. Thus using the wings to generate lift has a dramatic advantage over pure thrust. To obtain four pounds of vertical lift using a rocket, you must point straight up and generate four pounds of thrust. If instead you elect to use a wing to generate four pounds of lift, you need only generate one pound of thrust and that would allow the wings to generate four pounds of lift. The wings, in other words, provide a true "mechanical advantage" over pure rocket thrust, reducing the thrust (and therefore fuel consumption) required to counter gravity by a factor of four. Hence SA's RLV has three features that dramatically reduce propellant consumption: 1) Inlets to capture atmospheric oxygen rather than carry the oxidizer on board; 2) Fuel efficient engines; 3) More efficient horizontal lifting trajectory.

Since the performance of emerging suborbital launch systems is not yet publicly available, in order to properly quantify the dramatic effect of SA's advantages in reducing propellant consumption and cost, it seems appropriate to compare SA's orbital launch system to the most fuel-efficient, rocket-powered, orbital launch system existing today--the Russian Soyuz first designed in the 1950's and still in use today. Variants of Soyuz were used to launch the very first satellite as well as the first man into orbit. It is interesting to note that in fifty years no one (not even the US Government with the Space Shuttle) has developed a more fuel-efficient and cost-effective rocket-powered launch system capable of deploying passengers to orbit than Soyuz. Even recently awarded NASA contracts to develop new launch systems to service the International Space Station have as their objective to create a US capability to achieve costs "equivalent to" not "less than" that of Soyuz. Furthermore, although some work is in progress with respect to developing rockets for missions such as interplanetary transfer, it does not appear that any major dedicated effort is underway to dramatically increase the fuel efficiency of rocket engines that are capable of accelerating from earth to orbit. Thus for the foreseeable future, Soyuz seems indicative of the "best in class" as far as fuel-efficiency and cost-effectiveness for transporting passengers to orbit on rocket-powered launch vehicles.

The Soyuz consumes 600,000 pounds of propellant, and expends all its hardware, to place its two crewmembers and one "paying passenger" into orbit about the earth. That is the equivalent to the takeoff gross weight of a jumbo jet, all discarded on every mission, at a price of $20 million per passenger. As a result of its aforementioned advantages, SA's RLV will consume only 35,000 pounds of propellant per passenger placed in orbit. That is equivalent to the amount of fuel consumed by a charter aircraft, and no hardware is expended--every aspect is fully reusable, further reducing cost. Thus the impact of SA's technology is dramatic: similar in nature to the difference between "expending a jumbo jet" and "chartering a business jet" to place each passenger in orbit.

To compare two "orbital systems" is relatively straightforward, as the conditions required to reach orbit are fairly well defined: lift passengers up to an altitude of 62 miles or more (so they are above the vast majority of the atmosphere) and accelerate them to 17,500 mph (so their centrifugal force exactly offsets the force of gravity). However, comparing suborbital launch systems is less straightforward, as some may be traveling great distances while others merely go "straight up & down." In each case, a portion of the energy consumed is used in lifting each passenger up vertically in altitude (increasing the passenger's potential energy, which is a function of the altitude) and another portion is consumed accelerating the passenger's velocity (increasing the passenger's kinetic energy, which is a function of the velocity squared). SA plans to provide its guests the optimum overall suborbital experience: a combination of both orbital altitude and hypersonic horizontal travel. Even so, the total propellant consumed per passenger on SA's suborbital excursion is just 1500 pounds, with no hardware expended. That is about equivalent of the amount of fuel consumed per passenger taking a trip on a large turbofan-powered commercial airliner. All that is needed between flights is refueling. Once again, the dramatic advantage of SA's technology is apparent: it enables SA to offer affordable suborbital excursions in a price range that 72 million people are already spending on international travel each year.

High reliability is another major factor in reduced operating expenses. All launch vehicles to date have been powered by rocket engines, in which they have operated with a dismal historical failure rate of 13%. As would be expected insurance premiums for such vehicles track failure rates, hence premiums can be as high per mission as twenty percent of the sum insured (typically the total value of the vehicle and payload carried onboard). Since the emerging suborbital personal space flight industry does not have an insurance database yet, it may be instructive to discuss the impact of reliability and associated insurance rates on the satellite launch industry, which includes decades of available data. If we assume a launch vehicle costs $100 million and the sum insured is $500 million ($100 M for launch vehicle and $400 M for the payload, such as one or more satellites), then with a 20% rate, the premium would cost $100 M, doubling the price of the launch. To reduce the overall price to our orbital launch service customers, we have developed an Aerospaceworthiness (ASW) Standard and all of our systems will be designed, built, maintained and operated in compliance with the Standard. Compliance with the ASW Standard allows SA to qualify for aviation-based premiums rather than launch vehicle-based premiums. The aviation-based rates are typically less than 1% of sum insured per year, even for the supersonic Concorde. Thus, the savings generated by incorporating higher reliability in the design, enabled by the fuel-efficiency of the ejector ramjet engines, is substantial.

There has never been a debate over whether ramjets worked exceptionally well at high speeds, delivering exceptional fuel efficiency. Ramjets were flight tested up to hypersonic speeds back in the 1960's! However, the use of those ramjets was limited by their inability to operate effectively at low speed. They had to be boosted up to supersonic speeds by a separate system, which proved to be cumbersome. We have overcome that deficiency with the introduction of ejectors in the ramjet inlet that operate at low speed to entrain and compress air and direct it down the inlet, and as a result, SA has opened up the opportunity to provide our guests a safe, green and affordable total experience.