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Über dieses Buch

This book provides readers with a clear description of the types of lunar and interplanetary trajectories, and how they influence satellite-system design. The description follows an engineering rather than a mathematical approach and includes many examples of lunar trajectories, based on real missions. It helps readers gain an understanding of the driving subsystems of interplanetary and lunar satellites. The tables and graphs showing features of trajectories make the book easy to understand.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Launching to Interplanetary Orbits

Abstract
A spacecraft’s trajectory starts with its launch. Although the trajectory of the launcher is not calculated by a space systems engineer, the trajectory in which the spacecraft is put by the launcher is of extreme importance. Not only is it the starting point for the trajectory design, it also determines the spacecraft mass which makes the launcher selection a critical decision during any spacecraft design.
Robin Biesbroek

Chapter 2. Transfer to a Planet

Abstract
In the previous chapter the importance of the escape energy, C3, was highlighted and how it was used to calculate launcher performance. In this chapter we take a closer look at C3 values for transfers to different planets.
Robin Biesbroek

Chapter 3. Gravity Assist Maneuvers

Abstract
We have seen what it takes, in terms of energy and transfer time, to reach another planet from Earth. However we have also seen that for many planets, in particular Mercury and the outer planets, the energy levels are too high to reach for current launchers. In this chapter we take a closer look at the concept of gravity assist maneuvers, and what the impact is on the transfer energy.
Robin Biesbroek

Chapter 4. Deep-Space Maneuvers

Abstract
So far we only examined trajectories where the maneuvers were given by the spacecraft at departure from Earth and/or at arrival at the destination. A third position where a maneuver could be given is during the trajectory. Since the position is between planets, this is referred to as ‘Deep-Space Maneuver’ (DSM).
Robin Biesbroek

Chapter 5. Lunar Transfers

Abstract
We have seen that direct transfers to celestial bodies in the sky can fairly easily be calculated using the linked conic approach and a Lambert solver. After this, a transfer to the Moon should look easy. Unfortunately, transfers to the Moon cannot be simplified using the linked conic approach: the Earth is too close by and its gravity, even when arriving to the Moon, is still present. Therefore there will be two main gravity forces acting on the satellite, and we cannot always ignore the presence of the Sun’s gravity. A linked conic approach, which assumes that there is only one main gravity force, does not apply here. In this chapter we will look at different ways to get the Moon. In order to understand how to get there though, we first need to understand what are the characteristics of the Moon.
Robin Biesbroek

Chapter 6. Arrival Conditions

Abstract
By now we have seen different ways to arrive to a planet: direct transfers, transfers using gravity assist maneuvers and transfers using DSMs. The next step is to decide what to do when we arrive at the destination. Do we simply fly by like Mariner 10 did with Mercury? Do we enter into an orbit around the planet or do we land on it? From the arrival conditions, not every planetary orbit can be achieved. Nor can we achieve any entry point in the atmosphere of the planet. In this chapter we will look into the possibilities and consequences of different arrival conditions.
Robin Biesbroek

Chapter 7. Planetary Orbits

Abstract
Though all chapters have discussed how to get from Earth to a planet, and even how to enter an operational orbit around a planet, the type of operational orbit has not been discussed yet. The operational orbit selection depends on many factors, such as ground coverage for scientific missions, coverage to a lander for relay satellites, or the need for certain Sun illuminations due to constraints acting on the power sub-system. There are different types of planetary orbits, and these will be discussed in this chapter.
Robin Biesbroek

Chapter 8. Auxiliary Calculations

Abstract
In this final chapter we take a closer look at some important aspects that influence the system design, such as high long eclipse times can we expect, and which opportunities are there to communicate with Earth or with surface elements. Finally, we take a brief look at budget summaries and discuss margin philosophies.
Robin Biesbroek

Backmatter

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