Our project, its origins, goals and outcome is best described in the following abstract, which was presented at the German Aerospace Congress 2004 in Dresden:

Do we need a Spaceshower?

“The most critical problems facing humans in longduration space´Čéight, after
the biomedical problems, are the psychosocial and psychological problems“
Oleg Atkov, Russian Cosmonaut (237 days aboard Salut 7, 1984)

In this abstract we want to raise the question if it is necessary to draw our attention also to apperently unimportant issues of future manned space missions.

We want to discuss this question considering the example of body hygiene as a basic need of human beings. Furthermore we want to point to a project that had the opportunity to research on a possible active principle for a microgravity shower during two parabolic flight campaigns.

Especially in this year Mars has become a potential goal for a manned exploration in the next decades in both politics and public because of the ESA mission MarsExpress and the NASA rover missions. ESA had already written this goal in its Aurora Programme[2] and also Nasa has a ready to use Reference Mission on stand by[3]. In these studies it is considered that such missions will last round about 750 days including 200 days for the journey to and from mars. The crew has to perform such long duration missions on self-supporting basis, for this a high level of of functionally teamwork is necessary.

But everybody knows, that a good teamwork is only possible when all crewmembers are in a mentally stable condition and feel themselves in a good shape. A great factor for this is to consider the human needs of a good body hygienics. For example everybody doesn’t feel well in a hotel with bad cooked food, hard beds and unhygenic bathes. So it must be standard that on long duration misions there is a good supply with food, beds and finally hygienic equipment that ist used with pleasure and not with antipacity. The utilisation of this equipment must be simple and comfortable.

For our shower it means that it should works like at home with streaming water that must not be circumstantial sucked off from the body afterwards as in currently used and planned shower devices. A shower based on ultrasonic or the use of washrags is - in consideration of the written reflections above - out of question.

To accelerate water droplets in microgravity other fields of forces than gravity are necessary. An electrostatic field for example provides three different principles of acceleartion of water droplets through volumina forces:

(1) Inside of an inhomogenious electrostatic field there exists a force due to a different distribution of charges inside of a dipole like a water.

(2) Furthermore there is a force because of dielectric effects inside of a condensator which a shower cubicle based on electrostatic fields will be.

(3) There is also a force acting if water droplets are charged either positive or negative. Based on this reflections and with ESA’s help we were able to observe the flight path of water droplets in an inhomogenious electrostatic field during the 4th Student Parabolic Flight Campaign and the 32nd Professional Parabolic Flight Campaign.

Because of the gained data we could give evidence about the portion of the three named effects to the whole acceleration. At this time it’s still noticeable that the biggest portion of acceleration is leading back to the force due to a charge of the droplets, so that the dieelectric forces and forces due to the theory of dipoles play only a subordinate part. Numerical simulations of these assumptions show a perplex similarity with the real trajectories.[4]

Nevertheless the strength of the electric field, which we need to accelerate the waterdrops sensibly, is a problem. This topic contains a high potential for more research, because this electrostatic field must be installated around the shower completely. But for such an installation we need a feasible strength of the electrostatic field for human beings.

We hope that our project makes a small contribution for a better planning of long duration missions in future.

[1] http://www.spaceshower.de
[2] ESA/EXPLO-PP(2001)01,rev5 „Aurora – Envelope Programme Preparation Period – Programme Proposal“, 2001
[3] Special Publication 6107: „Human Exploration of Mars: The Reference Mission of the NASA Exploration Study Team“, 1998
[4] “First Evaluation of Experiment Data” available on http://www.spaceshower.de

Download this abstract as pdf in the Downloads section.