Exotic Systems

It's interesting that many of the more exotic ideas for achieving interstellar travel derive their inspiration from science fiction. Perhaps the most obvious example of this is the warp drive, with which we have become familiar through Gene Roddenberry's epic Star Trek series. Miguel Alcubierre, a Mexican theoretical physicist, was intrigued by this idea, and in the early 1990s he set about attempting to find a way of describing how it might work within the formal framework of Einstein's theory...

Popular Operational Orbits

Now that we have a grasp of the three principal distinguishing characteristics of orbits shape, size and orbital inclination we can begin to look at the Earth orbit types that are most commonly used by spacecraft operators. Obviously, if we allow all possible variations in these three characteristics, then there is an infinite number of resulting Earth orbits to choose from The popular orbits that we are about to introduce, therefore, are a small subset of this vast number of possibilities, and...

Halo Orbits Around Lagrangian Points

Lagrangian Points

In earlier chapters, we described a variety of orbits around Earth, but in this section we discover that it is possible for a spacecraft to orbit around a point in space where there is no mass This rather fascinating state of affairs requires some explanation. The story starts in the 1770s with an Italian-French mathematician named Joseph Lagrange. Note that this is about 100 years after Newton gave the world his revelations about how objects move in gravity fields, giving the world's...

Third Body Forces

Third-body force perturbations are caused by the gravitational influence of a third body in addition to the spacecraft and the Earth. The Earth is not isolated in the universe there are other celestial bodies out there, the gravitational fields of which can have a significant effect on the motion of an Earth-orbiting spacecraft. The Sun and the Moon have the greatest perturbing effect. If we think about these bodies, and look at Figure 3.7, then the total gravity force governing the motion of...

Where does the Suns energy come from

The region of space surrounding the Sun is not called the solar system simply because of the gravitational grip that the Sun exercises over its attendant planets. It is also because of the total dominance it has in governing the space environment from the inner planets out to a distance on the order of 100 to 200 astronomical units (AU). This outer boundary of the solar system, called the heliopause, is the place where the Sun's influence ceases and the interstellar medium the stuff between the...

Primitive Model of the Universe

WE live in a world where it is difficult to extract ourselves from what might be called the collective knowledge of the human race. We are surrounded by huge information banks storing the collected thoughts of the clever people who have shaped the way we think about the world. Among these resources we can include our own education from our earliest years. In addition, we have the written word, the spoken word through television and radio, and access to the World Wide Web, which provides a view...

The Electrical Power Subsystem

As we recall from Table 7.1 in Chapter 7, the main function of the power subsystem is to provide a source of electrical power to support payload and subsystem operation. This job is critical to the overall health of the spacecraft. Just about every type of spacecraft payload and all the subsystems, with the exception of the structure and possibly the thermal control, need a reliable source of electrical power to operate. A failure, or brief interruption, of the power subsystem function can have...

Choosing the Best Orbit

The five types of orbit we have discussed are popular with spacecraft operators, but how do we select the best of the huge number of possible orbits to choose from for a particular spacecraft mission This question is central to the activities of the team of project engineers tasked with the job of the spacecraft mission analysis. The quick answer is that the spacecraft needs to be in the right place, that is, the right orbit, so that the spacecraft payload can most effectively achieve its...