IceMole
The IceMole is a combined drilling and melting probe for ice layers ( cryobot ). The area of application extends from glaciers over the Antarctic to extraterrestrial regions. The probe is being developed by a team at the FH Aachen . The advantage compared to conventional melting probes is that the IceMole can change its direction in the ice by partially controlling the heating segments on the probe head and in this way can also drill back to the surface. This is done using a hollow screw on the probe tip. With it, the probe can not only pick up an ice core that can be scientifically investigated, but also pull itself through layers of dirt.
From the idea to development
The IceMole is developed using a rapid prototyping process. The first prototype was developed for use on terrestrial glaciers by August 2010 and successfully tested on a Swiss glacier in September. The next generations of the melting probe should also be able to be used in extraterrestrial regions. Possible destinations are the polar regions of Mars , Jupiter's moon Europa and Saturn's moon Enceladus .
The probe is being developed by a student project team in the aerospace engineering department of the Aachen University of Applied Sciences under the direction of Bernd Dachwald.
The project team has set the following goals:
- Terrestrial applications:
- In 2–3 years: glaciers and layers of ice
- In 4–6 years: The ice and subglacial lakes in the Antarctic and Arctic
- Extraterrestrial applications:
- In 10–15 years: The ice-covered polar caps of Mars
- In 20–30 years: Jupiter's moon Europa and Saturn's moon Enceladus
High demands are placed on the project. The probe is not only tested for reliability and robustness, but also for autonomy and environmental compatibility.
history
The first melt-down probes were already in use in the 1960s. These probes had a simple functional principle: they were heated at their tip and melted downwards with the help of the force of weight . The downside was that they were difficult to use and difficult to control. Conventional ice core drilling, on the other hand, is technically mature and therefore easier to carry out. But they also require a great deal of effort. You need drill rods, a lot of staff and a laboratory. This is why conventional ice core drilling cannot be used as an autonomous system. The combination of the two systems - melting probe and ice core drilling - allows the positive properties of both methods to be used and the disadvantages to be eliminated. The IceMole concept is therefore an important approach to further develop the technology for researching ice layers.
IceMole 1
The first prototype "IceMole 1" has a square cross-section of 150 × 150 mm. The angular shape is important for the drive system, as the probe head is not only made of heatable copper, but also has a hollow screw in the center of the head. Therefore, the torque generated by the screw must be absorbed by the geometry. The copper head houses four heating segments that are arranged in a square and can be controlled separately. If only one side of the head is heated and the constant tensile force of the screw acts on the ice surface, the IceMole can slowly pull itself around a curve with a radius of ten meters. The IceMole can move freely through the ice. The power supply and communication run via a supply cable to a ground station on the ice surface, which distributes the data to a PC unit. This cable is unwound from the probe when it is melted down.
In addition to propulsion, the hollow screw has a second important property: When moving in the ice, the screw absorbs an ice core that runs through the entire length of the probe. This ice core can be analyzed and evaluated within the system. The scientific instruments needed for the exploration can be integrated into the probe as a payload. Due to the maneuverability of the IceMole, these are also brought back to the surface. This was not possible with previous methods because the ice channel left by the probe freezes over again in a layer of ice that has not been heated. Melting probes that are unable to maneuver simply stay in the ice. The freezing of the ice channel has the positive effect that the probe can decontaminate itself with a mechanism and thus penetrate into closed environmental systems. Removing impurities from the probe is essential in order not to contaminate a closed ecosystem. Such a scenario would be conceivable in the case of a subglacial lake, to which the IceMole could melt through in order to then examine it on site for biological organisms. This in-situ measuring process makes the IceMole a powerful robot that works even under extreme environmental conditions. It is therefore ideal for use in extraterrestrial regions.
| Melting rate | Max. 0.3 m / h |
| Heating element | 4 × melting head |
| Power heating elements | ~ 2200 W |
| Average thermal output | 1000 W |
| Drive motor power | 25 W |
| Weight | 30 kg |
| External dimensions | 150 × 150 × 870 mm |
Field trials
The first field test took place in September 2010 on the Morteratsch Glacier in the Swiss Upper Engadin near Pontresina. The primary goal of this field test was to test and prove the drive concept under real conditions. This could be shown with the following drilling scenarios:
- Hole 1.5 m at an angle of 45 ° upwards against gravity
- Horizontal drilling with a length of 5 m
- Drilling 3 m at an angle of 45 ° downwards, through three layers of sediment (sand) and a curve with a 10 m radius
The test results show that the IceMole concept is a practicable approach to bringing scientific instruments into deep ice and then retrieving them again. Another advantage of the IceMole compared to drilling is that biological contamination is minimized and the process can be carried out to a large extent independently. The results were presented at the Antarctic Science Symposium 2011 in Madison , Wisconsin (USA) and the European Geosciences Union 2011 in Vienna , Austria .
Transport of the equipment to the Morteratsch Glacier by helicopter.
IceMole moves 45 ° upwards against gravity.
The melted canal, viewed from below.
IceMole 2 - URMEL
The IceMole team has been intensively developing the prototype since October 2010. The aim is to optimize the system. In addition, the successor "URMEL" has a new head shape with twelve heating segments and four side heaters for an even better and tighter curve radius. In addition, he gets a gear specially designed for these requirements, which should make the probe lighter and more efficient.
| Melting rate | Max. 1 m / h |
| Heating element | 12 × melting heads, 4 × per wall side |
| Melting head | Max. 2400 W |
| Melting capacity per wall side | 600 W |
| Drive motor power | 25 W |
| Weight | 25 kg |
| External dimensions | 150 × 150 × 1200 mm |
| Number of cable containers | 5 pieces |
| payload | fluorescent biosensor |
The supply cable is no longer unwound from the probe, but pulled behind it by the probe in several containers, similar to a train with wagons. Additional sensors can be integrated into these containers, which can then be used permanently in the ice. This is of great interest to researchers around the world, as they can accommodate sensors in the deep ice. The next field trial is planned for the northern hemisphere in summer 2012.
The intended goals for the 2012 field experiment were
- Test and validate the traceability of the probe. This shows that the system can bring a payload back to the surface.
- Dig a horizontal and a vertical "U"
- To travel a distance of 40 m
- To be operational for periods of 50 to 150 hours
- Independently uncouple and position cable containers
Use in the Enceladus Explorer
In 2012, the “EnEx - Enceladus Explorer” research project, funded by the DLR space agency , emerged from the IceMole student project . Scientists from six universities (FH Aachen, RWTH Aachen , TU Braunschweig , Universität Bremen , Universität der Bundeswehr München and Bergische Universität Wuppertal ) are working on the development of technologies for navigable ice melting under conditions similar to those on Saturn's moon Enceladus. Among other things, they developed a navigation and detection system as well as a decontamination and sampling system that were built into the meltdown probe. In November and December 2014, a field test took place in the Antarctic in which the EnEx-IceMole was used to take a sample of subglacial water from a depth of 16 meters below the surface of the ice.
Individual evidence
- ↑ a b The IceMole cometh - Novel design could help probe explore frozen environs on Earth and beyond . In: Nature Publishing Group (ed.): Nature News . April 30, 2011. doi : 10.1038 / news.2011.261 . Retrieved April 30, 2011.
- ↑ a b c IceMole team: The IceMole ice research probe . In: Student project - aerospace engineering . Aachen University. 1st May 2011. Archived from the original on July 25, 2011. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved April 27, 2011.
- ↑ Enceladus Explorer: Ice Mole takes a water sample. In: astronews.com. February 12, 2015, accessed May 14, 2016 .
