National Aeronautics and Space Administration

Glenn Research Center

Power Systems for Future Venus Exploration Missions

By: Thomas Vo

Principle Investigator: Dr. Geoffrey Landis

Mission Objectives and Overview

The research I will be involved in over the summer will be part of future NASA exploration missions to Venus. The scope of the research will be focused upon the power systems of the vehicles that will be used for the aforementioned missions. The power system, like in most space applications, will rely on the use of solar arrays to harvest the energy from the Sun. Although solar array applications have proven successful on other applications such as the Mar’s Rovers, the harsh environment of Venus unfortunately does not allow for the same technology to be directly applied to a future mission.

Although Venus is very similar to Earth in size and gravity, it has much different characteristics that may complicate the use of solar arrays as a power source. One of these characteristics is the highly reflective sulfuric clouds that increasingly impede upon the sunlight as it approaches the surface of the planet. The cloud cover, along with the dense atmosphere consisting more than 96% of carbon dioxide produce the solar array performance-reducing effect of extremely high temperatures. This is caused by the cloud and atmosphere of Venus creating the strongest greenhouse effect in the solar system. The combination of these conditions and their effects on the use of solar arrays will be further investigated. If after investigation it is determined that a practical sized solar array cannot be used, alternative power sources will have to be explored.

My Role as a Research Associate

The research work that I will be conducting will be to determine, based off of data from previous Venus exploration missions, whether or not a practical solar array based power system can be applied at lower altitudes on Venus. Before doing so I will need to explore the current technologies available for current photovoltaic cells as well as understand the atmospheric characteristics of Venus. This includes analyzing what part of the frequency spectrum is available at various altitudes from the Sun’s rays.

The desired goal is to have a practically sized solar array power system operating at the lowest altitude as possible. In order to achieve this, solar array technologies that operate well in the frequencies spectrum available at lower altitudes would need to be implemented. If a suitable solar based power system configuration can be identified this would serve as an enabler for low-altitude flying robotic exploration missions or thinking optimistically, possible land rover missions.
My personal goals for this summer research will be to:

1. Determine the following things related to the research and tie them together:
i. What frequency spectrum comes through at lower altitudes on Venus?
ii. What solar cell type would best operate at the frequencies at lower altitudes?
iii. Determine if and how any other environment factors or other characteristics of Venus would interfere with the use of solar cells.

2. Allow for the ability for a different researcher to come after me and be able to carry-on the research and interpret my findings.

3. Gain more research and analysis experience as an engineer by taking a problem presented to me and learning how to effectively break it down to be solvable.

Although many Venus exploration missions have been conducted, not many of them have been have been underneath the perpetual sulfuric cloud cover and close to the planet’s surface for detailed images and experiments. Some research studies done show that Venus may have been similar to Earth billions of years ago but a runaway greenhouse effect had caused it to become the extremely harsh environment it is today. By getting exploration missions closer to Venus’s surface and learning more about how the planet became the way it is, we can learn more about how our planet functions.

I have personally always been interested with the area of robotics and although this research is not directly related to robotics, it is still a very exciting topic for me to work on. I will put my best foot forward to help and be part of the next exciting generation of exploration vehicles and missions.