Tag: Bennu

China’s Chang’e4 Probe becomes first spacecraft to land on the Far Side of the Moon.

Don’t call it the dark side! Just because the Moon keeps the same face towards the Earth doesn’t mean the other side is dark. In fact the side of the Moon we can’t see gets just as much sunlight as the side we can see. Still the Lunar Farside has always been a land of mystery.

We do have photographs of the farside, taken by the lunar orbiter series of space probes that made detailed images of the entire Moon’s surface in preparation for the Apollo landing, see image below. However, even during the heyday of Apollo NASA never considered landing a probe on the surface of farside let alone a manned landing. NASA’s reason for avoiding the farside is quite simple, if you go behind the Moon in order to visit the farside you’re not only out of sight, you’re out of radio contact, so an unmanned probe couldn’t get its data back to Earth anyway! Because of this the Moon’s farside remained untouched for almost 50 years after Apollo.

The Farside of the Moon as compiled from Lunar Orbiter Photos (Credit: NASA)

Now however China’s National Space Agency (CNSA) has succeeded in landing the Chang’e 4, a sophisticated robotic probe that even carries a small rover, onto the Moon’s farside. So how did the Chinese resolve the problem of communicating with the Chang’e 4 as it landed in Aitken Basin, the Moon’s largest and oldest impact crater. Well they did so by first putting a relay satellite named Queqiao into lunar orbit. In this way Chang’e 4 will remain in constant contact with its command center back on Earth. See image below.

The Queqiao Relay Satellite keeps the Chang’e 4 Lander in contact with Earth (CNSA)

The Chang’e 4 was launched aboard a Long March 3B carrier rocket back on December 7th and went into lunar orbit on December 12th, see image below. As is usually the case with Chinese space missions there was no public statement of exactly when the Chang’e 4 would land, the announcement came only after Chang’e 4 was safely on the ground.

Launch of the Chang’e 4 Lander (Credit: CNSA)

But Chang’e 4 did land safety and has already begun to send back close up images from the surface of farside, see image below. Then after about a day to check out all of the lander’s systems the Chinese ordered Chang’e 4 to deploy it’s 6-wheeled rover named Yutu. See images below of the Yutu rover descending from the Chang’e 4 main lander.

Ground level Image of the Farside of the Moon (Credit: CNSA)
The Yutu Rover at the bottom of its ramp (Credit: CNSA)
The Yutu Rover making the first Tracks on the Farside of the Moon (Credit: CNSA)

In addition to experiments dealing with lunar geology and interactions of the solar wind on the lunar surface the Chang’e 4 will be carrying out some simple low frequency radio astronomy observations. You see here on Earth all of the electronic devices that are a part of modern society interfere with all of the low frequency signals coming from outer space, and more and more the high frequency ones as well. But on the farside of the Moon Chang’e 4 will be shielded from all of mankind’s artificial signals allowing it to see those from astronomical sources only. Radio astronomers hope that one day the farside of the Moon will serve as a platform for huge radio telescopes with which they can see the Universe without worrying about artificial interference.

Chang’e 4 represents another major step forward in China’s space program. Having become only the third nation to launch humans into space China is currently developing its own, small space station and is moving forward with robotic lunar and interplanetary probes. Taking a slow but steady approach as opposed to NASA’s herky jerky bursts in different directions China hopes to put a man on the Moon sometime in the mid to late 2020s, the same time frame as NASA (see my post of 31Dec2018). In that case we are in another space race back to the Moon, if a quieter one. I wonder who will win this time!

Before I go; with all of the excitement of New Horizons exploring Ultima Thule and Chang’e 4 landing on the Moon’s farside it was easy to miss the news that the Osiris-REX spacecraft has gone into orbit around the asteroid Bennu, the smallest, least massive object which a space probe has ever orbited. Now Osiris-REX will take a few months to study Bennu in order to determine a suitable landing spot from which it will obtain a sample of the asteroid for return to Earth.

Close up view of the asteroid Bennu as seen by the Osiris-Rex space probe (Credit: Earth Sky)

Space News for March 2018.

It’s been a quiet month as far as space exploration is concerned. The most interesting news items are actually updates of earlier stories but are rather important in the long term.

The first item I’d like to discuss concerns astronaut Scott Kelly and the continuing research into the medical effects of his yearlong mission to the International Space Station (ISS). You may have heard reports that because of his time in space Scott Kelly and his twin brother Mark Kelly were no longer identical that being in space had actually changed Scott’s DNA!! The image below shows Scott and Mark together, Mark is the one with the mustache.

Scott Kelly (left) with his Brother Mark (Credit: Space.com)

Well that’s not quite true. In fact a very important phrase ‘the expression of’ was left out of some news stories. Now what exactly does that mean? Well, our DNA can ‘express itself’ differently under different environmental conditions.

For example, if you eat a huge amount of food and drink a lot of beer your DNA will express itself by producing a lot of fat cells to store all those calories and you will become obese. On the other hand, if you eat right and exercise you DNA will express itself by producing muscle cells and you will stay trim and fit. Same DNA, it just expresses itself differently depending on what environmental conditions its exposed to.

What the latest medical tests have revealed is that the change in the expression of Scott’s DNA has amounted to about 7%. That’s quite a lot actually but about the same as the results that had been published earlier and within the range of normal variance for DNA expression. Click on the link below to be taken to NASA’s official announcement of the results of Scot Kelly’s medical tests.

https://www.nasa.gov/feature/nasa-twins-study-confirms-preliminary-findings

Before I go on to another subject, Scott Kelly also made some news this week by giving an interview in which he voiced his opinions of America’s space program and its future. The big takeaway from the interview was Scott’s criticism of NASA’s continued low budgets and the increased competition from China. Scott’s warns; “I think that China will overtake the US in the space business–If we allow them to.”

Scott is also concerned about the Trump administration’s recent plans to cut all funding to the ISS starting in 2025 despite the fact that the station’s expected working life takes it to 2028. Kelly is more hopeful when it comes to the scheduled test launches later this year of both Space X’s and Boeing’s space capsules. The first tests this year will be unmanned but hopefully starting next year NASA will no longer be dependent on the Russian’s in order to get our astronauts into space.

And speaking of NASA and the Trump administration the other news this month is that the space agency has continued with its plans to design, build and launch into deep space a Lunar Orbiter Platform called Gateway. The idea behind Gateway is to establish a small space station either in lunar orbit or an orbit around both the Earth and Moon. This station will give NASA experience in operating in deep space as well as a place to carry out solar and astrophysical experiments. The image below shows an image of the planned Gateway station.

Design Illustration of Lunar Gateway Station (Credit: Space.com)

The problem is, take a guess, money! Since Trump has directed NASA to a goal of returning astronauts to the surface of the Moon and then on to Mars where’s the money for Gateway. Once again it seems that NASA just can’t seem to set a clear goal for itself and get the funding necessary to achieve it.

NASA has been without a permanent Chief Administrator since Trump took office and just last week the agency’s interim administrator retired leaving NASA without any real boss. Without leadership from congress and the white house America’s space program will continue to founder without direction.

On a somewhat brighter note, NASA is at least making plans for the outside chance that the Earth will be struck by the asteroid Bennu on 21Sept in the year 2135. According to the best estimate the 500-meter in diameter space rock has a 1 in 2,700 chance of colliding with our planet on that day.

Right now the NASA probe Osiris-REx is on its way to Bennu on a mission that includes taking a sample of the asteroid and returning it to Earth. As a part of this mission NASA should get a better idea of Bennu’s orbit and therefore a better idea of whether Bennu is a future danger to Earth.

Should that prove to be the case NASA is developing a concept it calls the ‘Hypervelocity Asteroid Mitigation Mission for Emergency Response’ or HAMMER. Depending on just how big Bennu is HAMMER will impact on the asteroid to nudge it into a safe orbit or carry a nuclear bomb to destroy it. The image below shows the asteroid Bennu compared to a couple of more familiar objects.

The Asteroid Bennu (Credit: News.com)

Now where have I heard all that before? In a sense NASA is simply using Bennu as an example of a potentially dangerous asteroid to design a mission around. Based on the first part of this post I wonder whether or not by 2135 it will be a Chinese spacecraft that ends up protecting us from Bennu?