HANOVER, N.H. – In the 1960s during the Cold War, the U.S. Army Engineer Research and Development Center’s (ERDC) Cold Region Research and Engineering Laboratory (CRREL) designed a device, commonly referred to as a Rodriguez well, or Rodwell, to harvest water under the ice in Greenland and Antarctica to sustain U.S. facilities by providing water for drinking, hygiene and other needs. Presently, NASA is working with CRREL to assess whether that same technology can provide water for human-inhabited research stations on Mars.
A CRREL-designed Rodwell currently supplies water for the Amundsen-Scott South Pole Station, a year-round research station at the geographic South Pole operated by the National Science Foundation. Two and a half years ago, NASA reached out to CRREL experts and requested the laboratory’s involvement in adapting their Rodriquez well simulation model to help design a Rodwell for Mars.
“We’re helping NASA do research work on Mars with our Cold Regions laboratory — they’re depending on us to explore technology called a Rodriguez well,” said ERDC Director Dr. David Pittman. “A Rodriguez well is a way of basically drilling for water in arctic regions through big layers of ice. NASA wants to use this concept for water on Mars.”
Evidence has come back from orbiters around Mars showing massive ice deposits at mid-latitudes, not exclusively at the poles. This evidence indicates that the deposits are primarily pure water ice, though it has not been sampled yet.
“It makes for a very attractive resource for any missions to Mars,” said Dr. James Lever, a research mechanical engineer from CRREL. “We could bring the water from Earth, but the fact that there’s a massive ice deposit means we could melt it and have water for drinking, hand washing and things like that.”
Major differences between the atmospheres of the two planets create some challenges. One of the biggest differences is the Martian atmosphere is a very low-pressure carbon dioxide atmosphere rather than Earth’s higher-pressure nitrogen-oxygen mixture. The pressure on the surface of Mars is quite close to the triple point of water, where water would boil with any additional heat input or cause ice to sublimate rather than melt.
NASA and CRREL are working closely together to investigate what effects Mars’ low-pressure atmosphere would have on a Rodriguez well. The two organizations are creating tests to study whether water can be melted from ice deposits and used for Mars-based research facilities.
Researchers are working to answer other questions including whether the heat input can be controlled to avoid boiling, what the heat transfer rates to the ice and the atmosphere are, and how much power would be required to produce adequate water using a Rodriguez well on Mars.
“You have to supply that heat from the surface by warming up the injected water,” said Lever. “At the South Pole, that heat is provided by waste heat from the electrical generators. On Mars, we would do something similar, but we have to answer questions such as, ‘Do we enough waste heat to operate this well, and can we control its input to avoid boiling?’”
When NASA first approached CRREL to use its model for a Rodriguez well, the laboratory needed to adapt it to Mars, which Lever says can be done, but there are a number of assumptions that need to be examined and reviewed in an energy analysis. The two organizations are now working towards experiments that will test a Rodriguez well and ensure it will be capable of producing enough water to meet astronauts’ needs for a variety of Mars mission scenarios.
“CRREL has successfully employed this innovative technology to support human habitats in the Arctic and Antarctica,” said CRREL Director Dr. Joseph Corriveau. “I am thrilled to see the potential application of the Rodriquez well technology to support the NASA mission to the extreme cold Martian environment.”
In early implementations of the device, a Rodwell was a way to take advantage of what would otherwise be waste material, in this case waste heat, to generate fresh water for personnel stationed in remote, frozen climates. NASA is working to send humans to Mars – a place that once was assumed to have a dry climate but scientists have since discovered otherwise.
Dr. Stephen Hoffman, a contractor employed by the Aerospace Corporation and working for NASA, says there’s a lot of ice at the poles and lower latitudes and that a Rodriguez well, which the U.S. Army Corps of Engineers has a lot of experience with, might be a way for NASA to support astronaut crews who are eventually sent to Mars.
“We are trying to get a better handle on whether that’s really viable or not,” said Hoffman, who has been working with the CRREL team since the start of the project. “We need to use the expertise and experience that comes from real world knowledge, which the CRREL engineers have with Rodriguez wells, to ensure we get a realistic assessment if this is something that can be used on Mars.”
The discovery of massive ice deposits on different latitudes of Mars’ surface and the notion of being able to use Rodwells to produce potable water from those deposits will help propel two of NASA’s goals.
“One is to look for and understand whether life exists elsewhere in the universe, which includes the planets in our neighborhood,” said Hoffman. “Another charge that NASA has is to expand the human presence in the solar system, so sending people to the moon or Mars is one of the most basic charges that NASA has.”
Everywhere life is found on Earth is usually in association with water of some sort. Hoffman says they are taking that starting point and searching for life on Mars in the proximity of water.
“We don’t find it in, for example, solid ice, but we do find it on the margins of ice,” said Hoffman. “Mars doesn’t have liquid water on the surface — the pressures at that point are too low for lakes, rivers or bodies of water to exist on the surface.”
But Hoffman says there is buried ice that’s covered by debris, which provides a layer of insulation. NASA suspects that if life is going to be found, it’s going to be somewhere in proximity to that ice.
“So we want to find ice and find out what’s in it and if there’s life associated with it,” said Hoffman.
Having a sustainable source of water is not the only reason why NASA is exploring the Rodwell option. By using a Rodriguez well to supply Mars-based research facilities with water, NASA will also be able to reduce the payloads of space craft en route to Mars, increasing each mission’s efficiency.
“We can also use the water as a component for making propellant, so the crews that are going to Mars can come back,” said Hoffman. “If we can go there and use water to make that propellant, then we don’t need to bring it with us, it’s another efficiency. We might be able to get away with fewer launch vehicles, making the whole endeavor much more efficient and much more affordable.”
Not having to transport additional water or propellant to Mars makes an enormous difference in cost and reduces the number of space launches by being able to fully utilize resources on site.
CRREL and NASA have completed the first phase of testing the Rodriguez wells in pressure controlled chambers to check the viability of using the devices on Mars’ surface. The next phase will involve larger scale models and larger chambers. While the Rodwell could be a valuable asset, it is only one of the many tools NASA is pursuing with the goal of eventually placing humans on Mars. Hoffman says NASA is working diligently to ensure they can meet their directive and place a human on Mars by the 2030s.
“I started working on Mars missions in the 1980s, and I’ve been doing it ever since,” said Hoffman. “I’ve invested my professional career to try and achieve that. We will get there.”