NASA scientists scientists are building the next generation ChemCam with upgrades and brand new spectral capabilities for the NASA Mars 2020 rover.
As the NASA Curiosity rover roams the surface of Mars, its ChemCam captures the chemical makeup of its surroundings with a specially designed laser system. It is the most powerful laser to operate on the surface of another planet. The burst of infrared light it fires lasts only a few billionths of seconds, but it is powerful enough to vaporize the spot it hits at more than 8,000°C. Even from a distance, the ChemCam can examines rocks and soil using a process called Laser Induced Breakdown Spectroscopy (LIBS), where laser bursts atomize and excite components and spectral images capture their chemical signatures.
Here on Earth, scientists are already building the next generation’s ChemCam with impressive upgrades and brand new spectral capabilities for the NASA Mars 2020 rover, named for the year of its scheduled launch. In addition to a faster LIBS system, the SuperCam will feature an entirely new conduction-cooled laser system to provide the non-destructive analysis ability of Raman spectroscopy, capable of detecting carbon-based signatures of organic materials.
Together with the Centre National d’Etudes Spatiales (CNES) and The Research Institute in Astrophysics and Planetology (IRAP), Thales Group is in the final stages of testing the compact SuperCam system that will eventually endure harsh Martian conditions. They have already built and tested a full, representative model.
Unlike Curiosity’s LIBS-only functionality, this new instrument will be able to switch between a LIBS mode and a Raman mode of lasing, a method that requires two different laser colors to excite and probe molecular vibration energies for its non-destructive chemical identification. The second color is produced by a crystal that doubles the 1064 nanometer frequency used for LIBS measurements – which now produces 10 times as many shots in each burst of the laser for faster sampling.
This second, 532 nanometer beam will allow Mars 2020 to detect molecular structures evident of organic matter — evidence of past life. The new optical architecture required to produce the two operation modes, however, was not without its challenges.
The upgraded LIBS oscillator uses a diode pumped Nd:YAG crystal, as opposed to ChemCam’s Nd:KGW, which provides the longer bursts but requires new methods to ensure functionality over a large temperature range. Because the Nd:YAG absorbs over a narrow range of frequencies to lase at a given temperature, the SuperCam uses a multicolor stacked diode that can pump with a wide spectrum to account for a range in temperatures.
“This laser is running in burst mode, but with this laser we can do 1000 shots in one burst while the ChemCam laser was 10 time less,” said Eric Durand, one of SuperCam’s developers at Thales Group, France. “We longitudinally pump this laser with a stack which is a broadband emitting so that when the temperature is changing, the ND:YAG crystal is still absorbing the light and the laser can be used over at least 50 to 60 degrees without temperature regulation.”
Adding another complication to temperature control, the KTP crystal producing the green, frequency doubled light required additional stabilization.
“The most difficult aspect was to achieve the temperature range also with the green wavelength because we have to keep the efficiency over the whole range, and it was only possible by heating a little the KTP crystal,” said Durand.
The temperature stabilization required to keep the system aligned and working for either mode is difficult enough to achieve in a lab, but this system was designed to have the same stability while on the rover as it traverses the rocky Martian terrain. Moreover, it has to meet tight size and weight restrictions that come with space travel and stay free of contaminants that would destroy its components – a feat achieved by sealing the instrument with laser-welding.
The robust and powerful abilities of the new SuperCam will be an invaluable chemical probe for the Mars 2020 rover and may just bring to life a whole host of new findings back to us here on Earth.
Android Go puts reliable smartphones in budget pockets
Nokia, Vodacom and Huawei have all launched entry-level smartphones running the Android Go edition, and all deliver a smooth experience, writes BRYAN TURNER.
Three new and notable Android Go smartphones have recently hit the market, namely the Nokia 1, the Vodafone Smart Kicka 4 and the Huawei Y3 (2018). These phones run one of the most basic versions of Android while still delivering a fairly smooth user experience.
Historically, consumers purchasing smartphones in the budget bracket would have a hit-and-miss experience with processing speed, smoothness of user interface, and app stability. The Google-supported Android Go edition operating system optimises the user experience by stripping out non-important visual effects to speed up the phone. Thish allows for more memory to be used by apps.
Google also ensures that all smartphones running Android Go will receive feature and security updates as they are released by Google. This is a major selling point for these smartphones, as users of this smartphone will always be running the latest software, with virtually no manufacturer bloatware.
Vodafone Smart Kicka 4
At the lowest entry-level, the Vodafone Smart Kicka 4 performs well as a communicator for emails and WhatsApp messages. The 4” screen represents a step up for entry-level Android phones, which were previously standardised at 3.5”.
The display is bright and very responsive, while the limited screen real estate leaves the navigation keys off the screen as touch buttons. It uses 3G connectivity, which might seem like an outdated technology, but is good enough to stream SD videos and music. Vodacom has also thrown in some data gifts if the smartphone is activated before the end of September 2018.
Its camera functionalities might be a slight let down for the aspirant Instagrammer, with a 2MP rear flash camera and a 0.3MP selfie snapper. Speed wise, the keyboard pops up quickly, which is a huge improvement from the Smart Kicka 3. However, this phone will not play well with graphics-intensive games.
Next up is the Nokia 1, which adds a much better 5MP camera, improved battery life and a bigger 4.5” screen. It supports LTE, which allows this smartphone to download and upload at the speed of flagships. It also sports the Nokia brand name, which many consumers trust.
Although the front camera is 2MP, the quality is extremely grainy, even with good lighting. This disqualifies this smartphone for the social media selfie snapper, but the 5MP rear camera will work for the landscape and portrait photographer.
The screen also redeems this smartphone, providing a display which represents colours truly and has great viewing angles. Xpress-on back covers allows the use of interchangeable, multi-coloured back covers, which has proven to be a successful sales point for mid-range smartphones in the past.
Huawei Y3 (2018)
The most capable of the Android Go edition competitors, the Huawei Y3 (2018) packs an even bigger screen at 5”, as well as an improved 8MP rear camera and HD video recording. The screen is the brightest and most vibrant of the three smartphones, but seems to be calibrated to show colours a little more saturated than they actually are.
Nevertheless, the camera outperforms the other smartphones with good colour replication and great selfie capabilities via the 2MP front camera – far superior to the Nokia 1 despite the same spec. LTE also comes standard with this smartphone and Vodacom throws in 4G/LTE data goodies until the end of September 2018. The battery, however, is not removable and may only be replaced by a warranty technician.
Comparing the 3
All three smartphones have removable back covers, which provide access to the battery, SIM card and SD card slots. The smartphones have Micro USB ports on the bottom with headphone jacks on the top. The built-in speakers all performed well, with the Y3 (2018) housing an exceptionally loud built-in speaker.
Although all at different price points, all three phones remain similar in performance and speed. The differentiators are apparent in the components, like camera quality and screen quality. It would be fair to rank the quality of the camera and battery life by respective market prices. The Vodafone Smart Kicka 4 performed well, for its R399 retail price. The Nokia 1, on the other hand, lags quite a bit in features when compared to the Huawei Y3 (2018), bwith oth retailing at R999.
SA gets digital archive
As the world entered the centenary of Nelson Mandela’s birth on Mandela Day, 18 July 2018, South Africa celebrated the launch of a digital living archive.
The southafrica.co.za site carries content about the country’s collective heritage in South Africa’s eleven official languages.
Designed as a nation building, educational and brand promotion web based tool, the free-to-view platform features award-winning photographic and written content by leading South African photographers, authors, academics and photojournalists.
The emphasis is on quality, credible, factual content that celebrates a collective heritage in terms of the following: Cultural Heritage; Natural Heritage; Education; History; Agriculture; Industry; Mining; and Travel.
At the same time as reflecting on the nation’s history, southafrica.co.za celebrates South Africa’s natural, cultural and economic assets so that the youth can learn about their nation in their home language.
Southafrica.co.za Founder and CEO Hans Gerrizen conceptualised southafrica.co.za as a means for youth and communities from outlying areas to benefit from the digital age in terms of the web tool’s empowering educational component.
“We can only stand to deepen our collective experience of democracy and become a more forward planning nation if we know facts about our nation’s past and present in everyone’s home language,” he says.
Southafrica.co.za, with sister company Siyabona Africa, is the organiser and sponsor of the Mandela: 100 Moments photographic exhibition that runs until 30 September at Cape Town’s V&A Waterfront-based Nelson Mandela Gateway to Robben Island. The 3-month exhibition, which runs daily from 08h00 until 15h00, is showcasing one hundred iconic Nelson Mandela images taken by veteran South African photojournalist and self-taught lensman Peter Magubane.