The Lunar Transverse Maps

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Revision as of 05:02, 29 March 2008 by Jriley (talk | contribs) (Via Borealis / Via Australis)
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The Lunar Transverse Maps Project

In 2009 massive amounts of new lunar data will become available to the public. This is a resource worth billions of dollars. Students can use the new data for their projects too.

Project Description

Most of the first generation of maps that will be produced from the new lunar data will be designed for scientific purposes. A different set of information will be needed for lunar engineering and mission planning. If software to generate these maps is made available to students then very wide participation is possible. The parameters that will be considered for mapping are:

The Lunar Transverse Maps

  1. Slope – Slope is the absolute value of the first derivative of altitude. This map will have contours defining the safe areas for specific activities like landing, rover movement, and buildings. For example, the Apollo rovers were limited to a maximum of 25 degrees slope.
  2. The Heat of the Afternoon – This map will detail the number of hours that a specific point is above the maximum safe level (> 43ºC or 110ºF). The contours will detail safe levels for human and robot missions that cannot afford complex air conditioning. The local value is dependent on latitude, altitude, sun angle, and local obstructions.
  3. Earth view – This map will show direct communication availability to Earth. This detailed information is critical above 65 degree latitude and is based on latitude, altitude, and local geography.
  4. Solar Power – This map will provide the number of hours per lunation of direct sun availability at a location. It considers altitude, local geography, and sun angles through the lunation.
  5. Cold survival – This map will show an engineering parameter that includes both the length of the night and the night minimum temperatures. The contours provide power requirements to survive the night and, near the poles, areas of special interest.
  6. Rising Sun – This map will show the time that the sun is first available at a site.
  7. Setting Sun – This map will show the time that the sun is last available at a site.
  8. Bolder Fields – These areas are too rough for landing, complicate movement, and require additional site preparation for activities such as construction.
  9. Points of Interest – These are sites attractive for exploring because of scientific interest or the locations for settlement.

Data Sources

This engineering map work cannot start until the new science data is available to the public. The primary sources for data are:

  1. Kaguya, Japan -- Full coverage with the most detailed photograph for orbit ever is to be made public in the 3rd quarter of 2009.
  2. Lunar Reconnaissance Orbiter (LRO), USA – Data will start to be public in the 2nd quarter of 2009 and continue for at least two years.
  3. Others – A number of other missions may make new data available in the same time frame.

Working the Data

The student developed maps need not cover the entire surface of the Moon but can be limited to squares of particular interest that can be calculated on a desktop or laptop computer. For example, one of the proposed maps will show slope. This map can be calculated directly from detail altitude data in the following manner:

Nine point version:

  1. Select the next square
  2. Consider 8 points around central square
  3. Calculate absolute value of the difference in altitude for each square with the central square
  4. Convert to degrees
  5. Place highest value calculated in new map central square
  6. Repeat
  7. Take special actions to button together the map sections.

X-Prize Examples

The X-Prize organization is currently running a contest with a 30 million dollar prize for the first private lunar rover. This contest is of great interest to technical students.

X-Prize Lunar Lander Challenge [1]

The winner must minimally:

  1. Safely land a robot on the surface of the Moon
  2. Travel 500 meters
  3. Send images and data to Earth
  4. Be 90% privately funded
  5. Complete by December 31, 2014

Special Considerations

To do an outstand job and go beyond simply winning a prize, the small rovers for the X-Prize will have to overcome a number of difficulties:

  1. Cost of Development – Development cost must be kept low and within the capabilities of an university undergraduate team. For example, it is possible to develop mechanical and electronic devices that work reliably at 110ºC and that can be frozen and thawed from cryogenic temperatures (<?100ºC), but these features are very expensive to develop and beyond the capabilities of most student projects.
  2. Easy lunar access – This effort requires a low cost trip to the surface of the Moon with the maximum amount of payload mass delivered for each dollar spent. This will place limitations on the selection of the landing site. It must be on the near side and within a limited range of latitudes near the equator.
  3. Safe landing – The landing site must not have bolder or small crater fields.
  4. Not too hot – The survey locations must have survivable temperatures in the day, not too high, if the rover is to survive more than a few hours. Different rover designs will have different cooling strategies that will determine the high temperature limitation it can survive.
  5. Points of Scientific Interest – There needs to be some real reason for the trip. Just getting there and declaring, “We won!” is hardly worth the cost of the trip.
  6. Something to Name – Millionaire supporters will want naming rights if they are going to put up this kind of money. Claiming such rights will require that a local geologic feature be documented better than it can be from orbit.

Two possible ways to meet these requirements follow.

Laying a foundation of a new industry

To win the Lunar X-Prize the rover must land safely and last a few hours before dying. This is hardly the capability needed to lay the foundation of an industry of remote lunar tourism. In robot tourism, people pay for the privilege of remotely driving a rover around and seeing new places. To do this the rover must last for months, not hours. Surviving the lunar environment over time is a difficult challenge. There are a number of ways to address the many problems.

Big wheeled Rover, “Proud Mary”

Via Borealis / Via Australis

One approach is to land near the equator on a flat plain in the early morning, race to higher latitudes over the next tens of hours, and then circle the Moon every lunation, thereby always remaining in a benign environment. Landing a low latitude insures that the rover can have the maximum amount of payload offered by the rocket. Racing to high latitudes (65 to 75 degrees) insures that the rover will experience only a limited range of temperatures that common electronic and mechanical devices can survive for long periods. Circling the Moon at high latitudes insures that the rover will never have to hibernate through the night at cryogenic temperatures and then wake up unharmed. This plan does require a lunar satellite to relay data and commands from the Farside.

To get these advantages, the rover will have to move constantly, but only at the speed of a fast walk of 12 km/hr maximum and 5.5 km/hr sustained (6.5 miles/hr and 3.4 miles/hr). This means the lunar rover must have larger wheels than any Mars rover, have available detailed maps of the path ahead, and be able to move autonomously for hours between Earth command opportunities.

The idea then is to develop software that will let students produce the critical local lunar maps from the new lunar data. In this process the students search out a route for the Via Borealis (the Northern Road) and the Via Australis (the Southern Road). The maps must allow checking slope, daytime top temperature, solar power availability, and Earth communication availability. The routes will include sprints across open lands, maze walks through dense bolder and carter fields, and paths through critical mountain passes. At present it is not even clear that such routes exist.

Via Borealis (the Northern Road) will run about 3750 kilometers (2400 miles) crossing the Mare Frigoris (Sea of Cold) on the Nearside and then crossing 2000 kilometers of Farside highlands to regain Earth view near the small Mare Humboldtianum (the Humboldt Sea).

Via Australis (the Southern Road) will start near Mare Australe (the Southern Sea) and cross many hundreds of kilometers of lunar highlands until it passes to the Farside and crosses the very old bottom of the South-Pole Aitken Basin, an area of high scientific interest.

The students will not be looking for a single route but instead every possible route that meets all the rover survival criteria. Once these roads are established, we will need to find side routes from the main roads to places of scientific interest closer to the equator that can be transversed in a view tens of hours on a pleasant morning.

Moon with Via Borealis and Via Australis

Sand Snake Rover

Sand Snake

An alternative means of keeping a rover within comfortable operating temperatures is to bury it in the lunar regolith. Lunar regolith transmits heat poorly so its rate of temperature change and the limits of the changes over a lunation are quite benign at even a fraction of a meter below the surface.

This suggests an X-Prize rover design as a sandworm. The rover would be snake like, at least as big around as your arm and several meters long. It would slowly move below the surface of the regolith in a serpentine movement when the surface is either too cold or too hot. Its main components are:

  1. Spade head for digging with sensors for temperature, IR, and light
  2. Body with distributed computer, batteries, housekeeping sensor
  3. Science section with camera and seismic sensors
  4. A tail section that can take temperature extremes to manage Lilly pad
  5. Lilly pad with photovoltaics, antenna, and temperature sensors

At any lunar site, the snake will have a few tens of hours in morning and again in the afternoon to mover freely around the surface. In the heat of the day it moves much more slowly under the regolith. A night or when the surface is just too hot or if a radiation storm is expected the sand snake will dig in at a steep angle and enters a low-power sleep mode. At the best times it will be able to move its front sections to the surface and arch it back exposing miniaturized camera and other instruments.

A snake rover is limited to sander areas of regolith and will have trouble in very rocky areas. Its only limitation of slope is fear that an avalanche will be set off by its movement that would bury the solar panels. Its design will be very challenging work in robotics. The major concerns for this design are managing the Lilly pad tail and digging deep enough as the regolith gets progressively denser with depth. Its lifetime will be limited by abrasive ware on its outer skin.

Polar Special

Expeditions, manned and unmanned, to the lunar poles have special requirements and will need special maps:

  1. Peak of eternal light – On these mountain tops and ridges, solar power is nearly always available.
  2. Small landing fields – We have never used either a mountain top or a ridge for a landing field on the Moon. What happens when a landing undershoots or overshoots the primary landing field?
  3. Cold & Dark Access – What is the exact path and its parameters (slope, Earth view, solar power) for moving from the best landing site to a site in permanent darkness.
  4. The Cold – The temperatures in the areas of interest are too cold for normal electro-mechanical devices, but not cold enough for available super-conductors.

The student mapping project could develop routes for polar expeditions that cover travel from the most favorable landing sites to the most interesting science sites. Also needed are routes from the northern and southern roads to all the peaks of eternal light.

Naming Rights

To make this idea work we will need to obtain some funding from private individuals and corporations. This idea will be a whole lot easier to sell if we have something to offer that they really want. One possibility is naming rights for minor geological and man-made features on the Moon. This is a major legacy possibility for potential supporters.

Astronomical naming rights have been much abused of late by Web sites selling star names and lunar prosperity without any right to do so. We need to have a believable path to official and permanent naming.

Astronomical naming rights are controlled by the International Astronomical Union. This is the organization of scientists that recently was in the news for demoting Pluto to the rank of dwarf planet.

The exact naming rules will need to be researched but the following actions should be enough:

  1. Point of interest – There is something about the site that stands out.
  2. New data – Provide new insitu data not available from obit.
  3. Publish – Publish the data as a monograph in an established scientific journal
  4. Submit – Obtain a member sponsor and submit the naming request to the Union

Some names will be easy to get approved:

  1. Deceased Scientists and Explorers
  2. Mission name (e.g. Sinus X-Prize [X-Prize Bay])
  3. Historic man-made artifacts (e.g. Tranquility Base)

Difficult names to get improved might include:

  1. Living people
  2. Company or product names
  3. George

State of the Action

In the spring of 2008 I am trying to raise money and resources for this project. If you are interested in any way, please contact Tom Riley.

Return to Student Projects List.