HAL Id: hal-01425928
https://hal.archives-ouvertes.fr/hal-01425928
Preprint submitted on 4 Jan 2017
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Safe landing of spacecraft without its destruction by the
means of three-dimensional landing stations
Adrian Fellhauer
To cite this version:
Safe landing of spacecraft without its destruction
by the means of three-dimensional landing
stations
Adrian Fellhauer
January 4, 2017
Abstract
Current cutting-edge technology focuses on the preservation of rockets through vertical landing or landing by wings. While these are valid and partially successful approaches, the idea in this note may help to extend the range of recoverable spacecraft. This is achieved by constructing a landing station which is located on the ground or on a drone ship and shall help guide the rocket so that it can land softly. Thus, the influences of wind, waves or lacking thruster precision can be partly compensated for.
1
Motivation
A major company has interest in making the lower stages of rockets reusable.[1] This may signify a certain economic value of reusability of spacecraft.
2
Idea
The idea is to construct a three-dimensional landing station on the ground (or mounted to drone ships), so that the landing station works as a stabi-lizer for a rocket which is to land. Only a rough idea is described, without any computations of stability. However, certain considerations regarding material and shape are given to hint towards a working construction.
The three-dimensional landing station will look like a part of a quadric (or a flower vase), where the top is rather wide and the construction has only the width of the rocket itself at its narrowest point.
3
The shape
The construction shall serve as a three-dimensional extension of the classic landing pad for usual rockets. We aim at reducing the modifications that have to be applied to the rocket to a minimum; however, as described below, there may be a trade-off between the cost of such modifications and the money saved from landing the equipment safely.
A two-dimensional section through the basic shape may look like this:
Note that the construction ought not to be solid, for else the thrust emitted from the rocket engine may push against this solid construction, causing it to be subjected to dynamics that may be difficult to calculate due to the complexity of the situation. The logical alternative is to use a steel skeleton construction.
In this case, one could make a modification to the rocket as thus: The shape of the rocket could be changed so that a horizontal cross-section through a standing rocket may look like this, seen from above:
The pattern is chosen so that the edges of the steel skeleton have a radial distance that is a multiple of the radial measure of one saw tooth. In this way, two advantages would be achieved:
1. The pressure exerted on the rocket hull by the construction would be distributed more evenly
2. Rotations will be prohibited
I do not know whether this modification will have adverse or beneficial impacts on aerodynamics and stability of flight.
4
Magnetism?
It is unclear to the author whether the forces of magnetism may be used for landing spacecraft more safely. One has to take care that these forces won’t interact with the rocket or any other equipment in an undesirable way, and there may be considerable energy expenditure.
References
[1] Eric Betz. The falcon has landed. now spacex is eyeing mars. Discov-ery, 38(1), 2017.
