The last 2 were among the most exciting years of space exploration! From Falcon 9’s multiple successful landings to water discovery on Mars, and from India’s cheapest mission to Mars to Elon Musk’s BFR to colonize Mars, we’ve seen a lot of breakthroughs.
Not that just we heard a lot of fascinating news, our hopes of colonizing the red planet reached a whole new level. But, besides all the hype that going on about Mars, it seemed that we have lost interest in exploring our near lying natural satellite – the Moon.
I’m not saying that space agencies are completely ignoring Moon and have rolled up their sleeves for Mars only. There are a lot of future unmanned missions to Moon as well. These missions will satiate our curiosity to explore the dark side of the moon. (“Dark side” refers to the unexplored, and not the lack of light on this side).
Is there anything to explore other than the dark side of the Moon?
If we keep the dark side out of the table, what exactly is left to explore on the Moon? There’s no atmosphere, there’s barely water and there’s no way to protect humans from radiation, so what’s the point?
There is a point! And it’s about the origin of the Moon. About what lies below its surface. This is something scientists need to pull the curtain off from.
There are a lot of theories but the real origin is still unknown. From a long chain of past missions, scientists have collected several Moon rocks and debris. Nothing disclosed the full picture, however.
Also, Dark side of the moon is still untouched.
This is why many space agencies have their several rovers and probe missions (with more advanced technology, obviously) lined up to explore the Lunar soil.
In coming years, USA, China, India etc. are going to send their probes to the moon. China has already announced to send a rover in 2018 to the far side so that an understanding of the geology of our natural satellite could be built.
China’s upcoming rover mission to Moon’s dark side
The upcoming Chinese Moon mission will be the most interesting Moon Mission we’ll witness after almost 5 decades. A rover on the dark side of the Moon will surely reveal a lot about Moon’s geology and surface.
The Chang’e 4 which is set to launch at the end of 2018, will have the most awaited technology that even NASA wish they had on Curiosity Rover. A GPR aka Ground Penetrating Radar.
This is something that even Dr. Fred of NASA’s Jet Propulsion Laboratory mentioned in his AMA on Reddit.
Question: What technology do you wish you could have put on the rover and what would it’s purpose be?
“A higher mounted camera to see farther and over low-lying features. Also, some kind of ground penetrating radar (GPR) to see bedrock layers underneath us. GPR will be on the future Mars 2020 rover.” – Dr. Fred Calef
Yes, NASA’s futuristic rover, scheduled to be launched in 2020, will have RIMFAX — an advanced GPR.
How Chinese GPR Chang’e 4 Works
I found details on how GPR of Chang’e 4 work from one of the patents filed by Chinese Academy of Sciences. Yes, CAS is closely working with China National Space Administration on their Moon mission.
But first, let’s see why do we need a GPR.
A GPR will allow scientists to see through the regolith of Moon’s surface. The similar things are expected from Mars 2020 and Chinese Mars Mission of 2020 as well (yes, another rover from China for Mars).
Fact: What’s a regolith?
Regolith, simply speaking, is the first layer of a rocky planet/satellite/asteroid. It basically consists of dust + sediments from broken rocks + more dust. In case of Moon, you can also add minute glass particles to this list.
This layer demonstrates the basic environmental activities of a terrestrial body, and how it gets transformed over the years.
Currently, we don’t know how the Moon looks from the inside and that’s what having a GPR will allow scientists to learn. China’s current rover, Yutu, does have a GPR on it but, it cannot see enough deep (because of a single transmitter and single receivers).
The patent discloses a completely new system that’ll have multiple receivers, to precisely read surfaces beneath the ground.
The new GPR for Chang’e 4 from Chinese Academy of Sciences: Equipment
Nerd Alert: The article gets a bit nerdy from here. If you don’t want to go into too much detail, you can ignore it and move on to the next section)
According to the patent application, China will use the Single-Transmitter and Multiple-Receiver (STMR) in their new GPR system.
The robotic probe will have two channel modules containing one transmitter and three receivers attached to the both side of the rover. The transmitter on the channel modules will emit the electromagnetic pulse and the reflected frequencies will be received by the receivers.
The two detecting channels modules will be having different frequency ranges. The first detection channel has a wider transmission band, which covers High Frequencies (HF)/ Very High Frequencies (VHF)/ Ultra High Frequencies (UHF), while its receiver only covers HF/VHF.
The second band is a small transmission band which only covers UHF for both emitting and receiving.
Also, the first channel module’s frequency ranges are between to 30-90 MHz with a Voltage Standing Wave Ratio (VSWR) being less than 3. While the frequency ranges of second detection module are 250-750 MHz with VSWR value less than 2.
The use of two channel modules suggests that if due to any reason one channel module fails then the second module will prevent at least prevent the complete breakdown, the system will still be useful to some extent.
How this new GPR system actually works?
Okay, that was enough about the equipment let’s move on to the real functioning of the whole system. Which is quite simple by the way.
The transmitter antenna emits an electromagnetic pulse signal towards the surface of the Moon. As the signal goes through different layers beneath the surface, some of the frequency gets reflected back to the receiver.
The channel detection modules then collect these frequencies and convert them into a digital signal after performing amplification and sampling. The data is then stored for transmission to Earth.
The same process will continue during the rover’s exploration of areas of Moon.
Soon we will use the same technology on Mars surface as well, thanks to China’s future rover and NASA’s Mars 2020 rover. We can say that Moon is our testing ground for Mar’s future technologies.
All I can say is that Moon is our testing ground for technologies that we want to use on Mars.
Besides all this, do you know why the far side of the moon is such a big topic for scientists?