advantage of several in-space technology developments to reduce launch requirements and eliminate the need to develop a large heavy-lift launch vehicle. This system would rely on advanced electric propulsion systems, reusable flight elements, and in-space storage and transfer of propellants. To make such an architecture feasible and affordable, the flight rate of large boosters would need to be increased through technology that reduces on-pad time and automates the checkout process. He also noted the importance of significantly reducing the amount of helium used for launch.
In the group session there was some discussion on what technologies could be of use to the emerging launch companies. There was little agreement. For example, on the topic of non-destructive evaluation, one speaker said that an emerging company would rather build a stronger structure than incorporate internal health monitoring. When asked how NASA can streamline operations, several participants said NASA should simplify systems and procedures as much as possible and make the flight system much more self contained and autonomous, all of which might require starting from stretch. There was also some discussion on the architecture proposed by Woodcock. He said the single most important technology advance would be advanced electric propulsion systems. Another participant noted that architectures that take into account the full cost of operations do not look like the Apollo architecture, but NASA keeps relying on Apollo-like architectures.
Session 3: Other Interested Parties
Emmett Peter (Walt Disney Company) began the session by presenting an overview of the engineering that the Walt Disney Company uses to ensure the safety and operability of its amusement park rides. These rides carry millions of passengers each year, which means that one-in-a-million incidents are more likely and system life and operational standards must be at a high level to prevent them. The systems are rarely able to incorporate off-the-shelf equipment. They are designed to be mistake proof, and they rely heavily on autonomy. For example, some systems use automated coupling and transfer of high-pressure gasses and fluids, with hundreds of coupling cycles each day. Peter also reviewed Disney’s automated maintenance verification system, which features clear responsibilities and timelines and incorporates handheld wireless units for technicians. After reviewing the NASA roadmaps, he said that consistency and commonality are useful but difficult to achieve. Also, classifying and qualifying parts in order of criticality is a good practice to assure that inspection is focused on the correct parts; the highest payoff for ground systems might be found in structural health monitoring and corrosion technologies.
Brian Wilcox (Jet Propulsion Laboratory) presented an architecture that offered a radical departure from traditional systems. His architecture would use a high-altitude, equatorially tethered balloon to winch rocket stages above to an altitude above 95 percent of the atmosphere. Launching rockets from a position above the atmosphere improves the performance of the small rocket systems that are featured in Wilcox’s architecture. Wilcox believes that mass producing small rockets at a rate of more than 5,000 per year would lead to significant cost savings over producing a few traditional rockets. The payloads from 222 of these small rockets would be assembled on orbit into large propulsion stages.
Edward Bowles (General Atomics) reviewed the development of the electromagnetic aircraft launch system (EMALS) and discussed the potential for using the technology for space launch. The next generation of U.S. aircraft carriers will use EMALS instead of traditional steam-powered catapults. EMALS will use linear electric motors to provide up to 300,000 pounds of force to launch aircraft and recover naval aircraft. Adapting this technology to develop a rocket launch assist system would require much longer linear motors to accelerate much larger vehicles to much higher velocities. The most expensive part of the space-launch EMALS system would be the power generation systems. The goal would be to accelerate a vehicle weighing 500 tons to a speed of Mach 3 using a track 8 miles long. Bowles suggested such a system could break even after about 40 launches.
In the group discussion, Peter said that the Disney Corporation designs their systems for constancy and interoperability from the beginning. He also said that they design with margins based on the part class with critical parts having significant margins. He also said that Disney uses stainless steel and a lot of brushing and coating to fight corrosion. Wilcox said that his system does not require any significant technology investment, and the concept could be demonstrated with a subscale balloon. Bowles said that the terminal velocity of his system is limited by