Jerome Pearson

The orbital tower: A spacecraft launcher using the Earth's rotational energy

Abstract The theoretical possibility is examined of constructing a tower to connect a geostationary satellite to the ground. The “orbital tower” could be built only by overcoming the three problems of buckling, strength, and dynamic stability. The buckling problem could be solved by building the tower outward from the geostationary point so that it remains balanced in tension and stabilized by the gravity gradient until the lower end touches the Earth and the upper end reaches 144,000 km altitude. The strength problem could be solved by tapering the cross-sectional area of the tower as an exponential function of the gravitational and inertial forces, from a maximum at the geostationary point to a minimum at the ends. The strength requirements are extremely demanding, but the required strength-to-weight ratio is theoretically available in perfect-crystal whiskers of graphite. The dynamic stability is investigated and the tower is found to stable under the vertical forces of lunar tidal excitations and under the lateral forces due to payloads moving along the tower. By recovering the excess energy of returning spacecraft, the tower would be able to launch other spacecraft into geostationary orbit with no power required other than frictional and conversion losses. By extracting energy from the Earths rotation, the orbital tower would be able to launch spacecraft without rockets from the geostationary orbit to reach all the planets or to escape the solar system.

The ElectroDynamic Delivery Experiment (EDDE)

The ElectroDynamic Delivery Experiment (EDDE) is proposed for a space demonstration. EDDE consists of an autonomous space vehicle powered by lightweight solar arrays, a bi-directional electrodynamic tether, and batteries for power leveling. The EDDE vehicle can modify its orbit repeatedly without rocket fuel, and can change all six orbital parameters by modulating and reversing the current flow in the conducting tether. The base spacecraft is connected to the service module by a 6-km-long electrodynamic tether, and is designed for 2 kW of power and a total mass of 180 kg. Tether lifetime of several years is achieved with a two-strand caduceus, with the strands connected every few meters. Tether libration is minimized by mass distribution and by active current control. The vehicle and tether system concepts are developed, the operational envelopes are examined, and potential applications are evaluated. The EDDE vehicle is about twice as fast as ion rockets for high-inclination orbital plane changes, and ha...

Low-cost launch system and orbital fuel depot☆

Abstract A new system is proposed for the low-cost launching of large quantities of rocket fuel into Earth orbit and the storage and transfer of the fuel to the NASA Space Station. The system consists of an electromagnetic launcher that fires heat-shielded fuel tanks into high Earth orbit, where they are captured by a long, rotating tether. The tether is in an elliptical orbit that ranges from high Earth orbit down to low Earth orbit, where it drops the fuel tanks into an orbit near the Space Station. The payloads are used for upper stage rockets, for stationkeeping propulsion, and for high-g-tolerant supplies for the Space Station. The system has the potential for launching more than 100,000 kg into Earth bit each year at a launch cost of

Integrated Lunar Transportation System

An integrated transportation system is proposed from the lunar poles to Earth orbit, using solar-powered electric vehicles on lunar tramways, highways, and a lunar space elevator. The system could transport large amounts of lunar resources to Earth orbit for construction, radiation shielding, and propellant depots, and could supply lunar equatorial, polar, and mining bases with manufactured items. We present a system for lunar surface transport using “cars, trucks, and trains,” and the infrastructure of “roads, highways, and tramways,” connecting with the lunar space elevator for transport to Earth orbit. The Apollo Lunar Rovers demonstrated a batterypowered range of nearly 50 kilometers, but they also uncovered the problems of lunar dust. For building dustless highways, it appears particularly attractive to create paved roads by using microwaves to sinter lunar dust into a hard surface. For tramways, tall towers can support highstrength ribbons that carry cable cars over the lunar craters; the ribbon might even be fabricated from lunar materials. We address the power and energy storage requirements for lunar transportation vehicles, the design and effectiveness of lunar tramways, and the materials requirements for the support ribbons of lunar tramways and lunar space elevators.

LEO Mobility Vehicle for Space Situational Awareness

The Air Force and DOD are addressing the problem of space situational awareness by a combination of ground-based optical and radar sensors, plus short-range inspectors launched with spacecraft. There is still a major need for long-range space patrol vehicles to provide space superiority. The LEO Mobility Vehicle (LMV) meets this need. It is like a UAV in space, free to roam Earth orbits as a versatile surveillance system with complete low-Earth-orbit (LEO) to geostationary transfer orbit (GTO) coverage on demand, to observe, inspect, and trail objects. The LEO Mobility Vehicle has very high delta-V for large orbit changes, and thus provides a new and unprecedented capability for space situational awareness, space-based space observation, and close-up inspection and surveillance of all objects in space, from LEO to GTO. One dedicated secondary payload ring on a Delta 4 or Atlas 5 could launch 18 LEO Mobility Vehicles, creating an operationally responsive space fleet completely covering LEO like the GPS satellites cover the Earth.