“Copyright © 2014 by J. Mírez, G. Portilla, T. Cortéz, H. De Las Casas

PROPOSAL OF A BICYCLE/STRETCHER FOR MOBILITY OF ASTRONAUTS ON THE MARS SURFACE

Jorge Luis Mírez Tarrillo

Universidad Nacional de Ingeniería - Peru

E-mail: [email protected]

Gerardo Alejandro Portilla Tuesta

Universidad Católica SantoToribio de Mogrovejo – Peru

E-mail: [email protected]

Teófilo Cortés

“Fabricaciones Mecánicas” Company FAMESA – Peru

E-mail: [email protected]

Humberto J De las Casas

Pontificia Universidad Católica del Perú, Lima, Peru

E-mail: [email protected] [email protected]

ABSTRACT

The importance of the transfer machine for astronaut on Mars for its various exploration activities is extremely important that your confidence level is pretty good both design and energy source because it will be in a totally isolated and hostile environment that is Mars. Given this hypothesized that taking into account the gravity of Mars is about one third of the Earth, the astronaut by oversizing can physically find physical activities quite effectively born so maybe an efficient and reliable way to transfer which would by a machine operating with own human strength. To do the most simple and efficient transfer machine is proposed as a bicycle. The amount of energy required to move the astronaut cycling to gravity of Mars was calculated, then a bicycle model with separable parts allowing it to this becoming a stretcher in case of accident or other necessity is required design, this was drawn and simulated in Solid Works software, later the first prototype was built in physical form having as name MPC-1, this was tested and improved in the Mars desert Research Station Mars Society in the wilderness of Utah - USA by the crew 140 and 141, for a period of 28 days. The calculation results demonstrated a low energy demand for transportation and testing in Utah desert could verify the reliability of the system, making the MPC-1 a good scan “Copyright © 2014 by J. Mírez, G. Portilla, T. Cortéz, H. De las Casas. Published by The Mars Society with permission” tool astronaut on Mars. The bike is assembled in 7 minutes, switch mode stretcher bike in 11 minutes. Field tests were on level ground, broken bicycle mode using dead load and mannequins.

1. INTRODUCTION

Mars is the fourth planet from the sun; it has a gravity which is 1/3 of the Earth’s gravity and a tenuous atmosphere (density atmosphere is equivalent to the Earth at an altitude of 30 km). Nowadays, Mars is a place of robotic exploration; they are working for supporting the human exploration. Numerous research programs have been carried out for many years in order to find how is the best way to move a group of astronauts to the surface of Mars and, when they arrived there, how they get the facilities to continue with the exploration.

Maintaining life on Mars under environmental conditions requires high reliability systems and also these systems have to allow multiple uses for different activities. The EVA's (extra vehicular activity) are activities taking place outside the habitat; each EVA is pre-programmed to minimize the risk and maximize the success through the return of information, experiments, data collected, etc.

The main purpose of these EVAs is the exploration of the terrain, for that reason, it is needed mobile units. Throughout them, astronauts have to be careful and work with highly portable and reliable systems. Being able to ensure the life of an astronaut or giving more security to the team are the reasons for the proposed design in this paper.

2. CONCEPT

Fig. 1: Assembled mode Bicycle Fig. 2: Disassembled mode Bicycle

The original idea was a detachable and portable bicycle (Fig. 1 and Fig. 2) that can be easily converted into stretcher and wheelchair. The construction strategy was to meet in group work, buy the necessary parts, assemble and build a structure under the modality test – failure, first in bicycle mode, and then, build the necessary parts of the design to turn it into a stretcher.

3. BUILDING

The building part was divided into two stages: The first stage involved the building of the prototype in Lima – Peru. First, the parts and materials were purchased and then, the building of the first prototype of the bicycle with the prospect of a stretcher started. The project was developed in a workshop of metallurgical processes using electric arc welding electrode (Fig. 3) and the first result was the first prototype of the bicycle (Fig. 4). During the first tests at this stage, the bicycle was quite unstable for the driver. The hours used for this stage were about 140 because the constant changes and adjustments in pieces were required.

Fig. 3: Teófilo Cortéz and colleagues during the Fig. 4: Gerardo Portilla during the first welding process test of the bicycle

The second stage involved the continuous improvements at the MDRS (Mars Desert Research Station). The project was seeking a better stability and height of the pedals on the ground to not let obstacles. Day 10th, after obtaining a functional prototype (Fig. 5), the project continued with the building of new parts and adjustments to the existing pieces for the stretcher mode; for that reason, available materials in the MDRS (iron and aluminum) were used. The process of improvements continued and the bicycle-stretcher conversion was almost ready (Fig. 6).

Fig. 5: Jorge Mírez and the first functional Fig. 6: Jorge Mírez working in the project prototype stretcher mode

4. TEST 4.1 FIELD TEST (In spacesuits) I. From pieces to bicycle: 7 minutes (Fig. 7). II. From bicycle to stretcher: 11 minutes (Fig. 8). III. From stretcher to pieces: 5 minutes.

Fig. 7: Jorge Mirez working in the bicycle Fig. 8: Jorge Mirez and Humberto De las mode Casas working in the stretcher mode

4.2 MODIFICATIONS AND ADJUSTMENTS I. The settings of nuts and bolts. II. Naming each piece. III. Placing signs to facilitate the assembly, disassembly and conversion equipment. IV. Inspection of wear, erosion and abrasion.

“Copyright © 2014 by J. Mírez, G. Portilla, T. Cortéz, H. De las Casas. Published by The Mars Society with permission” Jorge Mírez (part of the Crew 140th and 141th) throughout the 28 days, he has worked on this project through testing and control. He concluded, as final proof of performance, a journey of 4 km in the bicycle mode on the road (Fig. 9 and Fig. 10) and to test the stretcher handling in both, on flat terrain (Fig. 12), as well as on gullies (Fig. 11).

Fig. 9: 4 km in bicycle mode Fig. 10: 4 km in bicycle mode

Fig. 11: Stretcher on gullies Fig. 12: Stretcher on flat terrain

5. CONCLUSIONS

 It was possible to achieve the objective of designing and building a bicycle/stretcher using inexpensive materials available in Peru and in the MDRS.

 It was possible to verify that the equipment is capable of converting from bicycle to stretcher and from stretcher to bicycle; it can be reconfigured by one person.

 The materials of choice for the project, although the project succeed, they must be carefully chosen for reasons of weight, strength and durability over time.

 This project provides an alternative of mobility for astronauts on Mars; it can be improved and optimized to become more practical and reliable design, this security leads us to have a futuristic vision displayed (Fig. 13).

Fig. 13: Bicycle/stretcher in the MDRS (a Mars view)

6. REFERENCES

[1] http://www.marssociety.org/ [2]http://peru.marssociety.org/ [3]http://mdrs.marssociety.org/

7. ACKNOWLEDGEMENTS (From Jorge Mírez)

The Mars Society Peru. Pedro Manzur - Manager. Julio - FAMESA Company. Dr. Yseki. - Head, Department of Physical Medicine HNCH. The Provincial Municipality of Chota (hometown of Jorge Mírez). Teófilo Bustamante, Lely Delgado, among many others; thanks to everybody this project is a concrete reality.