Comets are relics of an era that has long since passed. They formed in the same accretion disk that gave birth to our Earth, Sun and the rest of the solar system but managed to avoid being subsumed into a larger celestial body. This, along with the amazing show they put on whenever they come close to the Sun, makes them objects of particular interest to star gazers and scientists alike. However few craft have studied them as their highly elliptical orbits make it incredibly difficult to do anything more than a flyby. That is, of course, unless you’re the ESA’s Rosetta spacecraft which just made history by deploying its Philae lander to the surface of the Churyumov–Gerasimenko 67P comet.
Many would have heard about the Rosetta craft recently as it was the first craft to ever enter an orbit around a comet which was achieved back in August. However few would know that it’s been on that journey for over 10 years as the Rosetta craft was launched in March of 2004. Since then it’s been slowly making it’s way to rendezvous with 67P, using multiple gravity assists to give it the velocity it needed to match the comet’s speed. Once it arrived at the comet it began imaging its surface in incredible detail, searching for a landing site for it’s attached Philae lander. In the early hours of this morning the Philae lander detacted from its parent craft and began its descent down to the surface and shortly after we received confirmation that it had touched down successfully.
It’s not all good news unfortunately as whilst the telemetry indicates that the lander did make it to the surface the anchoring harpoons that are on it’s feet did not fire. This causes two problems, the first (and most troubling) of these is that the lander is not securely fixed to the comet’s surface. In the minuscule gravity of the comet the lander weighs about 1 gram, meaning any out gassing from the comet could flip the craft over, or worse, send it tumbling out into space. Additionally those harpoons also contained instruments for measuring surface density, a lesser issue but still a blow to the project all the same. The ESA is currently investigating the reasons behind this and might refire them to ensure that the lander doesn’t get blow away.
Firing the harpoons again is risky but the people behind the Rosetta program have never been one to shy away from potentially mission ending decisions. Back in 2007 they scheduled an incredibly low altitude pass by Mars, a mere 250KM above its surface, in order to correct its trajectory to be closer to 67P. The trouble with this though was Rosetta couldn’t use its solar panels during this manoeuvre due to it being in the shadow of Mars, forcing it to power down for the duration. The batteries on the craft were not designed with this purpose in mind however and so this trajectory correction was dubbed The Billion Euro Gamble which, thankfully, paid off.
Rosetta and Philae both carry with them a host of tools designed to analyse the make up of the 67P comet including spectrometers, thermal imagers and radio/microwave based devices. The original spacecraft design was far more ambitious, including such things a sample return mission ala Hayabusa, however whilst it might not be as lofty a mission as it once was it’s still highly capable of giving us a detailed picture of what makes up this comet. This will then give us incredible insight into the early stages of our solar system and how it evolved into what it is today.
Hopefully the harpoon issues will get sorted out in short order and the Philae lander can continue its work without the possibility of it getting blown out into the depths of space. Rosetta’s mission is slated to continue through to the end of next year, just after 67P buzzes passed us on its journey back out to the edges of our solar system. Like all good space missions there’s potential for it to go even longer and here’s hoping that Rosetta and Philae will continue to deliver long past their used by date.
For a country that was barred from ever working with the leader in space technology the progress China has made in the last decade has been incredibly impressive. They’ve quickly gone from humble beginnings in 2003 where their first taikonaut made it into orbit to a fully fledged space station in 2013, showing that they have the technical expertise required to consistently attempt envelope pushing activities. Of course whilst the most interesting aspect of any space program is the manned activities (who doesn’t love seeing people in space!) there’s always the quiet sibling in the robotics departments, attempting missions that few humans will be able to attempt. I must admit that until today I was also ignorant of China’s robotic efforts in space but suffice to say they’re just as impressive as their human based accomplishments.
China’s Chang’e program (the name of the Chinese Goddess of the Moon) is a series of lunar spacecraft tasked with creating highly detailed maps and models of the Moon’s surface with the intent that that data will be used for future manned missions. Chang’e 1 was launched back in 2007 and remained in lunar orbit for 2 years. It created the most accurate and detailed sufrace map of the moon to date and, once it was done, plummeted into the surface it just mapped to send up a spray of regolith that could be studied from here on Earth. It’s successor, Chang’e 2, was launched in 2010 and had similar capability (albeit with higher resolution instruments and a lower orbit) but instead of being plunged into the moon at the end of its mission it was instead sent out to do a flyby of asteroid 4179 Toutatis. Its current trajectory will eventually see it hit interstellar space however its likely it’ll run out of fuel long before that happens and the purpose of the extend mission is to validate China’s Deep Space Tracking network.
Chang’e 3, launched just yesterday, will be the first craft China has ever launched that will land on the Moon’s surface. For a first attempt it’s a fairly ambitious little project consisting of both a lander and a rover, whereas similar missions usually go for a lander first prior to attempting a rover. The lander is an interesting piece of equipment as it contains a RTG as a power source as well as an ultra-violet telescope, making it the first luna based observatory. Whilst it won’t be anything like the Hubble or similar space telescopes it will still be able to do some solid science thanks to its location and it makes the lander’s useful life much longer than it typically would be.
The rover is just as interesting, being roughly equivalent to the Mars Exploration Rovers (Spirit and Opportunity) in terms of size and weight. It can provide real time video back to Earth and has sample analysis tools on board. The most important instrument it carriers however is a radar on its base allowing it to probe the lunar surface in a level of detail that hasn’t been done before, giving us insights into the make up of the regolith and the crust beneath it. It will be interesting to see what its longevity will be like as its power source is its solar panels (unlike its parent lander) and the lack of atmosphere should mean they’ll remain clean for the forseeable future.
As of right now there’s another 2 more missions in the Chang’e line both of which have similar capabilities with the exception of Chang’e 5 which will be a lunar sample return mission. After that it’s expected that China will start to eye off manned lunar missions, starting with the traditional flag planting operations and then quickly escalating to a fully fledged moon base not long after. It’s quite possible that they’ll accomplish that within the next 2 decades as well as their past accomplishments show how quickly they can churn out envelope pushing missions, something that other space fairing nations have been lacking as of late.
Whilst it might not be of the same heights we saw during the cold war there’s definitely another space race starting to heat up, although this time it’s between the private space industry and China. Whilst it’s likely that China will win the race to the Moon and possibly Mars I can’t help but feel that the private industry isn’t too far behind. Heck, combine Bigelow Aerospace and SpaceX and you’ve already got the majority of the Chinese manned program right there! Still this does not detract from the accomplishments the Chinese have made and I only hope that eventually the USA changes its stance on co-operating with them.
Almost 2 years ago the Phoenix Lander, was sent on its way to Mars. The Phoenix’s mission was simple, to search the north pole of Mars for the most fundamental building block we know: water. Just like the Spirit and Opportunity rovers it was only designed with a very short mission time in mind, approximately 125 martian days (sols). After that point the solar panels would not produce enough power for it to continue operations and was instructed to shut itself down until conditions improved.
Phoenix however wasn’t designed to endure the harsh martian winters. The solar panels it has are too small to generate any meaningful charge during the winter and the lander has no way of reorienting itself to maximise the small amount of solar energy it gets. The rovers have a one up on the lander in this regard since they can find a hill at the right angle to maximise their exposure or, in the case of the trapped Spirit, digging its wheels into the soft martian soil. So despite its name it looks unlikely that the Phoenix will rise out of the frigid winter ashes, but that doesn’t stop us from hoping otherwise:
Listen up, all you Phoenix lander fans! Beginning Jan. 18, the Mars Odyssey orbiter will start listening for any signs of life from Phoenix, which has been sitting silently on the frozen arctic region of Mars since its last communication in November 2008. The Phoenix team says hearing any radio transmission from the lander is high improbabl[e], but possible. Never say never….
“We do not expect Phoenix to have survived, and therefore do not expect to hear from it. However, if Phoenix is transmitting, Odyssey will hear it,” said Chad Edwards, chief telecommunications engineer for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We will perform a sufficient number of Odyssey contact attempts that if we don’t detect a transmission from Phoenix, we can have a high degree of confidence that the lander is not active.”
Odyssey will pass over the Phoenix landing site approximately 10 times each day during three consecutive days of listening this month and two longer listening campaigns in February and March. The listening attempts will continue until after the sun is above the horizon for the full 24.7 hours of the Martian day at the lander’s high-latitude site. During the later attempts in February or March, Odyssey will transmit radio signals that could potentially be heard by Phoenix, as well as passively listening.
From the mission onset I always held a slim, illogical bit of hope that the lander would survive the long martian winter. Mars has a track record for killing the majority of space craft we send at it (the “Mars Curse” has seen 50% of the missions planned for it fail in some way, although the Americans by themselves have a 72% success rate) so the Phoenix lander coming back alive after what is considered to be certain death for it would be one of those moments where impossible odds are overcome. Sure we’ve already got almost all the science we wanted out of the lander, but that doesn’t mean there isn’t more useful things we can do with it.
It also brought back another interesting fact about Mars, the number of both active and inactive craft we have on our red neighbour. There’s currently 3 orbiting satellites (Odyssey, Express and the Reconnaissance Orbiter), 2 rovers and a smattering of landers (all inactive unfortunately). Having this much infrastructure on another planet has proved to be a great boon for all missions that go there as the existence of orbiters that can function as communications relays means that we can get more data back to Earth for the same cost. Plus its just plain cool to know we’re capable of such things, and gives me hope that we will one day make Mars our second home (that’s a story for another day!).
So in about a week we’ll start to get an idea of whether or not the Phoenix will rise again. Either way we can still look upon the success of Phoenix with a smile, and should it come around again you can rest assured the scientific community at large will be both surprised and overjoyed.
It’s all a matter of time now.