For the last few months, the rover has been easing its way over what is called the “Murray Formation”, a transitional layer marking the separation points between the materials deposited over the aeons to create the gigantic mound, and the material considered to be common to the crater floor. Named in honour of the late co-founder of The Planetary Society, Bruce Murray, the formation comprises a number of different land forms, which the rover has been gradually examining.
On June 4th, 2016, Curiosity collected its latest set of drilling samples – the 11th and 12th it has gathered since arriving on Mars – on the “Naukluft Plateau”, a further region of sandstone within the Murray Formation, similar to the area dubbed the “Stimson Formation”, where the rover collected samples in 2015.
The aim is to carry out comparative geology between the two sites to determine whether or not their formation is related. The “Stimson Formation” sandstone strongly suggested it has been laid down by wind after the core slopes of “Mount Sharp” had been laid down by sedimentary processes the result of Gale Crater once being home to s huge lake, but which had then been subjected to fracturing by the passage of water. These bands of fractured sandstone have become more prevalent as the rover has continued up through the “Murray Formation”, so it is hoped that by obtaining samples from “Naukluft Plateau”, the science team will gain further understanding of precisely what part water played in the evolution of the slopes of “Mount Sharp” after the lake waters had receded.
Since completing the drilling operations, Curiosity has turned south, and is now climbing the mound “head on”, rather than gradually zig-zagging its way upwards.
The MSL rover has also provided geologists with another surprise. In mid-2015, the rover collected samples from a rock dubbed “Buckskin”. Reviewing the analysis of the minerals in the samples, as discovered by Curiosity’s on-board laboratory suite, scientists have found significant amounts of a silica mineral called tridymite.
“On Earth, tridymite is formed at high temperatures in an explosive process called silicic volcanism. Mount St. Helens, the active volcano in Washington State, and the Satsuma-Iwojima volcano in Japan are examples of such volcanoes,” said Richard Morris, a NASA planetary scientist at Johnson Space Centre. “The tridymite in the Buckskin sample is thought to have been incorporated into “Lake Gale” mudstone as sediment from erosion of silicic volcanic rocks.”
The find is significant because although volcanism did once take place on Mars, it has never been thought of as being silicic volcanism, which is far more violent that the kind of volcanism associated with the formation of the great shield volcanoes of the Tharsis Bulge and other regions of Mars. So this discovery means geologists may have to re-think the volcanic period of Mars’ early history.
China Launches Long March 7
Saturday, June 25th saw the inaugural launch of China’s Long March 7 booster, a vehicle I wrote about back in April 2016. The launch was also the first from China’s fourth and newest space launch facility, the Wenchang Satellite Launch Centre, located on Hainan Island, the country’s southernmost point.
The Long March 7 is a core component to China’s evolving space ambitions. Classified as a medium lift vehicle, it can carry around 13.5 tonnes to low Earth orbit (LEO), it will operate alongside China’s upcoming heavy lift launcher, the Long March 5. This craft will be capable of lifting around the same payload mass directly to geosynchronous orbit, and around 25 tonnes to LEO. Both vehicles will play a lead role in China’s plans to expand her explorations of the Moon, establish a permanent space station in Earth orbit by 2022, and reach Mars with automated missions.
The inaugural launch of the Long March 7 took place at noon GMT on Saturday, June 25th (20:00 local time). It carried a Yuanzheng 1A upper stage and a scale model of China’s next generation crewed orbital vehicle into an orbit of 200 km (120 mi) by 394 km (244 mi) as confirmed by US tracking networks.
Yuanzheng is an automated “space tug” China has used numerous times to deliver payloads to their orbits, and is capable of re-using its engine multiple times. It is most often used to boost China’s communications satellites into higher orbits.
The sub-scale capsule was used to carry out an atmospheric re-entry test to gather data which will be use to further refine and improve the re-entry vehicle which will form a part of China’s replacement for its ageing, Soyuz-inspired Shenzhou crew vehicle. This unit returned to Earth, landing in a desert in Inner Mongolia on Sunday, June 26th, after orbiting the planet 13 times. Also aboard the vehicle was a “cubesat” mission to test a navigation system, and a prototype refuelling system.
The Wenchang Satellite Launch Centre is also key to China’s evolving space operations, providing the country with far better access to equatorial geosynchronous orbit. It will also be central to China’s space station and planetary mission ambitions, and will witness the inaugural launch of the Long March 5 later in 2016.
In September, China also plans to launch the Tiangong 2 space laboratory, a replacement for the Tiangong 1 which was visited twice by crews in 2012 and 2013 for short duration stays. This launch will be from one of the country’s older launch facilities, and will be followed before the end of 2016 by a crew, who will spend around 30 days about the facility.
Pluto’s Active Ocean, Charon’s Mighty Grand Canyon
“Our model shows that recent geological activity on Pluto can be driven just from phase changes in the ice – no tides or exotic materials or unusual processes are required. If Pluto’s most recent tectonic episode is extensional, that means that Pluto may have an ocean at present. This lends support to the idea that oceans may be common among large Kuiper Belt objects, just as they are common among the satellites of the outer planets.”
This is a comment from Planetary Science Institute Senior Scientist Amy C. Barr, who with Noah P. Hammond of Brown University, has co-authored a new paper on the results of their analysis of geological evidence imaged by the New Horizons space craft as it sped by Pluto and its partner / moon Charon almost a year ago. Their conclusion is that Pluto’s ocean, deep under its icy shell, is still active.
Central to their idea is the formation of ice II. This is a phase of ice that is 25 percent more dense than the ice we are familiar with on Earth, which floats on water. Ice II forms at high pressures and low temperatures, the kind of conditions expected in Pluto’s ice shell. If it were to form, Pluto would experience volume contraction, causing compressional tectonic features to form on the surface – however, none have been found in any of the images New Horizons took of the planet, which included hundreds of the extensive “Sputnik Planum” ice field.
This suggests that Pluto’s interior is warmer than might be expected, and thus a liquid ocean could still be there – and still active – today.
At the same time the ocean paper was published, NASA / SwRI released a new image of Pluto’s partner / moon, Charon, revealing a huge “grand canyon” scoring its surface. Informally named “Argo Chasma”, it was fortuitously imaged by New Horizons high up on Charon’s limb, with sunlight falling across it in a way which made it possible for its overall dimensions to be approximated. It is believe to be a total of 700 km (430 mi) in length and around 9 km (5.5 mi) deep. By comparison, Arizona’s Grand Canyon is 450 km (280 mi) long and roughly a mile deep.
Can Boeing Get a Crew to the ISS On Time?
Boeing, the surprise winner of a contract to fly crews back and forth between US soil and the International Space Station, is racing to get its vehicle, the CST-100 Starliner, ready for an February 2018 crewed test flight. This is already some 4 months behind the planned launch date for the mission, originally slated for October 2017, and Boeing are remaining cautious about achieving it.
Starliner is one of the most technically complex designs the company has undertaken, as such, the company knows everything must flow smoothly for them to reach their target. It is one of two vehicles NASA plan to use as “space taxis” for the ISS, the other being the SpaceX Dragon 2 vehicle. This has a significant advantage over the CST-100 in that it is an evolution of and existing craft, the SpaceX Dragon cargo vehicle, rather than an entirely new and untried design.
However, both programmes have been constantly hampered by a hostile, Republican-led Congress, which had consistently under-funded the Crewed Commercial Transport programme since 2011, whilst simultaneously ordering NASA to spend more on the Space Launch System and Orion Multi-Purpose Crew Vehicle – despite the fact that both of those programmes are fully funded, and cannot be accelerated simply by awarding them more money.
Starliner has been further hampered by going over its allowed mass budget, forcing Boeing to re-examine the vehicle and get it down to a mass appropriate for launch atop the United Launch Alliance (ULA) Atlas V rocket. However, the company has paid the deposits required to reserve 4 Atlas V launches:. The first of these will be an uncrewed test flight in 2017, followed by the February 2018 crewed flight, and then two flights to the ISS before the end of the year.
It’s not clear which craft – CST-100 or Dragon 2 will make the first crewed flight to the ISS, but whichever it is, Boeing might end-up with the short end of the stick. NASA is due to cease funding the ISS in either 2024 or 2028. While Dragon 2 has a potential career beyond ISS operations, as SpaceX can continue to use it in a variety of roles atop their own Falcon family of launch vehicles, Boeing has no such luxury. Even the CST-100’s launch vehicle, the Atlas V might not have a long-term future; it will be facing increasing competition from SpaceX’s semi-reusable Falcon boosters, which can under-cut ULA’s launch prices by around 60%, and also from the orbital version of the New Shepherd reusable launch vehicle Blue Origin is slowly working towards.