Why The Moon Could Fuel Future Space Missions

A recent report funded and published by the United Launch Alliance outlines the the potential viability of mining the Moon for rocket fuel. At over 170 pages, it is quite a read but Philip Metzger, one of the authors wrote a good summary on his website. I thought I would try and make a similar summary here with slight more explanation, and where it fits into the future NASA plans of getting back to the Moon and going onward to Mars and beyond. It all revolves around water, or more specifically ice. For many years we thought the Moon was a baron rocky cold desert. The samples that the Apollo astronauts brought back from the Moon, and the Soviet Luna samples imply that there is no water in the rocks or regolith. The trace amounts of water found in the samples were assumed to be contamination. Although, in 2008, a study of the Apollo rock samples did show some water molecules trapped in volcanic glass beads. Also in 1978, Soviet scientists published a paper claiming the 1976 Luna 24 probe contained 0.1% water by mass. Plus the Apollo 14 ALSEP Suprathermal Ion Detector Experiment (SIDE) detected the first direct evidence of water vapor ions on March 7th 1971. None of these discoveries were taken as conclusive proof of water on the Moon at the time.

An image of the SIDE experiment from Apollo 14. It measured the energies and masses of positively charged ions near the surface of the Moon and also studied the interaction between the solar wind and the Moon as the Moon moved through the Earth’s magnetic field. Credit: NASA.

On September 24th 2009 it was reported that the Moon Mineralogy Mapper (M3) spectrometer on India’s Chandrayaan-1 spacecraft had detected water ice on the Moon. The map of the features show that there is more at cooler, higher latitudes, and in some deep craters. Basically, the parts of the Moon that see the least light like the poles and far into craters near the poles have managed to keep the water on and below the surface. This water is in a number of different states, some locked up in minerals, some in ice form, and others in OH form, not technically water but near. This has lead to a number of new possibilities of inhabiting the Moon and using its resources. This is why the United Launch Alliance funded a paper on the possible use of mining this water and using it as a future fuel source. By some estimates there could be as much as 10 billion tonnes of water on the Moon. The water could in theory be mined, and through electrolysis turned into hydrogen and oxygen, the fuel that got men to the Moon on the famous Saturn V.

Left side of the Moon Mineralogy Mapper that was located on the Chandrayaan-1 lunar orbiter. Credit: NASA

But you have to ask, why does it matter? the Moon is far away, and surely water is just useful for astronauts living on the Moon to survive. Well the report talks about the business case to use the water as fuel, in the form of hydrogen and oxygen. First we need to understand the commercial satellite world, and geostationary satellites. When first sending up such satellites, the way to do it was to use a multi stage rocket, with the first stage getting to a Geostationary Transfer Orbit (GTO) and then the second (upper) stage being used to get into the Geostationary Orbit (GEO). Recent years have allowed the first stage to be hugely improved and often reusable by companies like SpaceX and Blue Origin. The second stage hasn’t had the same improvements though. Traditionally the second stage was a normal, and very heavy liquid rocket. This meant that it was very expensive to get things to GTO, much more difficult than LEO. The rocket was also thrown away afterwards, and as it is so far out it will take hundreds or even thousands of years to burn up in the atmosphere. 

A diagram of the traditional way to boost communication satellites into orbit. Credit Dr Phil Metzger

Now we do have a better way to do it, sort of. I talked recently about the rise of electric thrusters. A lightweight, cheap and powerful solution when used over a long period of time. Over the time span of years they can pick up speeds of thousands of miles per hour. That is the biggest downside of them though, in this situation, slowly pushing the satellite to orbit, they take up to a year to get a satellite into position. That is a year that it could be making the owner money. By some estimates that year could lose $100 million in revenue just waiting for the slow thrusters. By all accounts though, this is still cheaper than launching a large traditional rocket upper stage. The electric thrusters are amazingly light comparatively, which means you need a smaller first stage to get it up to space in the first place. The key thing you have to remember about these geosynchronous satellites is that they already have a huge price tag, some can cost upwards of half a billion dollars to build and launch.Part of the reason is that they tend to be huge, in size and weight. Some have been as big as London double Decker buses, and weigh 6 tonnes. The rockets then need to get them to one of the furthest and time consuming orbits, a costly exercise. 


A diagram of the current way to boost communication satellites into orbit. Credit Dr Phil Metzger

So why can this Moon mining idea help? well the Moon is in lots of countries space plans at the moment. China are currently sending lots of probes, and by some accounts looking to get humans there. The USA are building the SLS which should be able to get humans to the Moon, and are also developing the LOP-G idea. The concept to have an orbital station around the Moon, almost like a fuel stop for rockets going on to further parts of the solar system. This idea to mine the Moon for hydrogen and oxygen could be transferred up to this orbital space station to be transferred to the rockets that need it. This is where the geosynchronous satellites come in. Imagine if this fuel, that is dug up and processed by robots, and then sent up to an orbital station could be brought back closer to Earth via a space tug. This space tug could meet up with the rocket with the satellite on board. The upper stage rocket could have been sent up with no fuel (the heaviest bit) and is fueled by this space tug. It would allow for the speed of the old style engines, but the weight of newer electric engines. As long as the price for this whole system is cheaper than the $100 million it currently costs, then it could be a viable option. All the while, setting ground work for space agency’s to have viable water sources that can be used for future exploration. It may be the future of space travel.

Atlas 5 taking off
Atlas 5 lifting off from pad 41 at Cape Canaveral Air Force Base. If this idea takes off, these rockets could propel much larger payloads into much bigger orbits. Credit: @marcuscotephoto on Twitter

Thank You for reading, take a look at my other posts if you are interested in space or electronics, or follow me on Twitter to get updates on projects I am currently working on.

Follow @TheIndieG
Tweet to @TheIndieG

The Geeky Geological Features of Charon

As talked about in a previous post, Charon was named after the wife if the discoverer James Christy. Since then the New Horizons probe has visited and taken some amazing pictures of the surface. As part of the mapping they have also started naming some of the craters and other geological features found on the surface, and they all have very fictional culture names. Although some have been accepted but he International Astronomical Union, there are still many that haven’t. As of April 2018 they have set out an agreed naming convention and set of rules for the names. They should conform to one of the following:

  • Destinations or milestones of fictional space and other exploration.
  • Fictional and mythological vessels of space or other exploration.
  • Fictional and mythological voyagers, travelers and explorers.
  • Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt.

So far there have been many provisional names given by the New Horizons team based on mostly science fiction franchises such as Star Wars, Star Trek, Doctor Who and Firefly. Most are still provisional, but some have been accepted

Charon Enhanced
An enhanced colour version of Charon taken by New horizons space probe. It is enhanced to show the differences in surface composition. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

A Terra is a large landmass or highland, and there is only one highland region on Charon. It was named Oz Terra after the Wonderful Wizard of Oz children’s novel by L. Frank Baum. The dark spots on the surface are called maculae in planetary science. The first is named Gallifrey Macula after the home planet of Doctor Who (Gallifrey). The second is the Mordor Macula after the base of Sauron in the Lord of the rings books by J.R.R. Tolkien. A planum is a scientific name for a plateau (elevated plain) and Charon only has one. Named Vulcan Planum after the home planet of Spock in the Star Trek Series. Terrae, Maculae and Plana are all being named after fictional destinations. A Mons is a planetary mountain, you may have heard of some of the Mons currently being explored by NASA rovers on Mars. Charon has three major mountains and are named after authors and artists. Butler Mons is named after Octavia E. Butler, an american science fiction author. Clarke Montes is named after Arthur C. Clarke, a famous English science fiction author who wrote 2001: A Space Odyssey. Kubrick Mons is named after Stanley Kubrick, a film director of films such as the shining and clockwork Orange. All three of the Mons names are accepted by the IAU.

Mordor Macula is located at Charon. A large dark area about 475 km in diameter near the north pole of Charon, Pluto’s largest moon. It is named after the shadow lands in J.R.R. Tolkien’s The Lord of the Rings.  It is not currently known what Mordor is. It may be frozen gases captured from Pluto’s escaping atmosphere, a large impact basin, or both. Credit: NASA

A chasma is a deep steep sided depression (a chasm), and are being named after fictional vessels. Argo Chasma is named after a ship in the Greek myth of Jason and the Argonauts, it is also the spaceship in the English translation of the Space Battleship Yamato anime series. Caleuche Chasma is named after the mythological ghost ship that travels the seas around Chiloé Island off the coast of Chile, collecting dead who then forever live aboard (much like Davy Jones). Mandjet Chasma is named after the solar boat of the ancient Egyptian God Ra. All three of the above Chasmas are recognised by the IAU. Macross Chasma is named after the SDF-1 spaceship in the Macross anime series. Nostromo Chasma should be known to most as the spaceship in the Alien films. Serenity Chasma is from the spaceship used in the Firefly series. Tardis Chasma is named after the infamous blue box flown by Doctor Who.

Annotated map of Charon, with provisional names for features. Credit: NASA/JPL.

There are 16 notable craters found on Charon’s surface, of which six have officially recognised names. They have all been named after characters associated with science fiction and fantasy. Dorothy Crater is named after the main character is the Wizard of Oz, also naming the only terra on Charon. Nasreddin crater is a sufi traveler from folklore. Nemo is after Captain Nemo from novels by Jules Verne. Pirx crater is the main character from the short stories by Stanislaw Lem. Revati Crater is named after the main character in the Hindu epic narrative Mahabharata. Sadako Crater is the adventurer who traveled to the bottom of the sea in the medieval Russian epic Bylina. All of the above craters have been officially recognised by the IAU. Alice Crater is named after the main character of the Lewis Carroll novels. Kaguyahime Crater is named after the princess of the Moon in Japanese folklore. Organa Crater is named after princess Leia in the Star wars films, along with Vader Crater, and Skywalker crater. Ripley Crater is one of the more studied craters and is named after the main character in the Alien films. Kirk Crater, Spock Crater, Sulu Crater, and Uhura Crater are all named after main characters in the Star Trek TV franchise.

Photo of Charon centered on Ripley Crater. Nostromo Chasma crosses Ripley vertically. Vader is the dark crater at 12:00, Organa Crater is at 9:00, Skywalker Crater at 8:00, Gallifrey Macula and Tardis Chasma at 4:00. Credit: NASA/JPL

Thank You for reading, take a look at my other posts if you are interested in space or electronics, or follow me on Twitter to get updates on projects I am currently working on.

Follow @TheIndieG
Tweet to @TheIndieG

Charon: The Man Who Gave His Wife a Moon

Charon Enhanced
An enhanced colour version of Charon taken by New horizons space probe. It is enhanced to show the differences in surface composition. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

On June 22nd, 1978 James Christy was trying to refine the orbit of Pluto when he noticed something odd about the images. Going straight to Robert Harrington, his supervisor at the U.S. Naval Observatory in Flagstaff, Arizona, together they concluded that they had found what we now know as Pluto’s largest moon Charon. Discovered just 6 miles away from where pluto itself was found (Lowell Observatory), discovering Charon began a journey from Pluto being a dot on a telescope to its own planetary system. With some amazing images coming from a probe NASA sent there, we have a glimpse of the edge of our solar system. The best part of the story, Charon is named after Christy’s wife.

40 years after christy
40 years on, Christy shows the images he used to discover Charon, and now one of the New Horizons images is his PC wallpaper. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Art Howard/GHSPi

In 1930, Clyde Tombaugh discovered Pluto, and although famous in itself, there was limited study on this dot in the far reaches of the solar system. So on the fateful day James Christy asked his supervisor Bob Harrington for something to do, Harrington pulled some telescope plates of Pluto from the Naval Observatory at Flagstaff to look over. Christy looked over them for some time under a microscope and noticed some inconsistencies with the images, with the asymmetry being different between them. In simple terms he noticed a bump on the side of Pluto that seemed to move over time. Although at first he thought he might be seeing things, when he took it to Harrington he agreed with the findings.

Jim Christy points
Jim Christy pointing to the photographic plate that he used to discover that Pluto has a moon. Credit: U.S. Naval Observatory

When  looking at other images of Pluto, the bump was constantly moving from one side to the other. Further examination showed the bump moved around Pluto at the same own rotational period, 6.39 days. There were two potential theories as to what it was, either Pluto had a mountain thousands of miles high (meaning Pluto was not very spherical) or it has a satellite in synchronous orbit. In the 48 years since Pluto’s discovery at Lovell Observatory in 1930, there had never been any evidence spotted that Pluto had a moon. The next steps included scouring the archives for more cases of an elongated looking Pluto.

The Charon images
The discovery at the US Naval Observatory, Flagstaff was seen as a time varying bulge on the image of Pluto. This is a negative version of the one Christy looked at. Credit: US Naval Observatory.

Christy measured the angle from the north where the strange elongation was. At the same time Robert Harrington calculated what the answer would be if the elongation was from a satellite. They then compared their results, and they were the same. To be sure they waited for the Observatories 61 inch telescope to make a final confirmation on the matter. On the 2nd of July 1978 new images showed an elongation exactly where they expected it to be. Five days later they announced the discovery to the world. Pluto’s first satellite had been discovered.

40 years difference
The difference of 40 years, top left is one of the images Christy used to discover Cahron, the big image is from New Horizons flyby. Credit: U.S. Naval Observatory; NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

By astronomical tradition, the discoverer of an object gets the first chance to suggest a name for the object. The name does not have to be recognised by the International Astronomers Union. Christy wanted to name the moon after his wife, Charlene. To make it sound more scientific he took his nickname for her “Char” and added an “on”. The “on” was from his interest in atoms, and words like proton and neutron. He suggested the name on the June 24th, 1978. Colleagues at the observatory prefered the name Persephone, but Christy noticed that Charon was actually a real Greek mythological figure. Charon is the ferryman of the dead, associated with the god Hades. Creepily the Romans identified Hades with their god Pluto. The name was eventually adopted on January the 3rd 1986.

The greek Charon
The name Charon was partially adopted because it is the name of the ferrymen of the dead in greek mythology. this is a nineteenth century painting by Alexander Litovchenko

Charon is the largest moon of Pluto, and is about the size of Texas. It also makes Charon the largest moon relative to its parent planet at about 12% of the size. So big in fact that Charon and Pluto are seen as a double planet or binary planets. They have a common centre of gravity that is outside of either of them. It is believed that it was formed by some sort of giant impact, much like the Earth and the Moon. The sheer size and proximity to Pluto meant it was a good choice for a scientific mission to take a closer look at the system. The mission, New Horizons was launched in 2006, with a  primary mission to performa flyby study of the Pluto system.

New Horizons Artist
An artistic impression of what New Horizons looked like when it passed Pluto and Charon. Credit: NASA Goddard Media Studios.

Passing about 18,000 miles (29,000 km) away from Charon on the 24th of July 2015, New Horizons gave the world a brand new stunning view of the moon from up close. At its closest point it was 7,800 miles (12,500 km) from Pluto, mapping both the planet and the moon using its long range imaging cameras. It mapped them to a resolution of 25 mi (40 km). The way they entered the system and the speed they were going allowed them to map all sides of both bodies. They took multiple images with the close range camera to find any surface changes. They also characterised the atmosphere, using the on board ALICE experiment.

Best Charon Images
A mosaic of the best images taken by New Horizons of Charon, from a few different angles. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

The science gained by New Horizons has given astronomers a new look into the outer reaches of the solar system, and it is still planning to take more images of comets and asteroids it comes into contact with in 2019. The first close up images of Charon were revealed  to the world at the John Hopkins Applied Physics Lab in Maryland to a packet auditorium. Jim Christy, the discoverer of Charon and his wife who it was named after were there at the unveiling, were recognized by the crowd. He said “When you go from this little blur in which you don’t actually see anything, to the enormous detail New Horizons sent back,” Christy said, “it’s incredible.” That amount of change in just 40 years.