martes, 16 de julio de 2019
Enabling Martian habitability with silica aerogel via the solid-state greenhouse effect
Abstract
The low temperatures1,2 and high ultraviolet radiation levels3 at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches4. Several ideas for making the Martian surface more habitable have been put forward5,6,7,8, but they all involve massive environmental modification that will be well beyond human capability for the foreseeable future9. Here, we present a new approach to this problem. We show that widespread regions of the surface of Mars could be made habitable to photosynthetic life in the future via a solid-state analogue to Earth’s atmospheric greenhouse effect. Specifically, we demonstrate via experiments and modelling that under Martian environmental conditions, a 2–3 cm-thick layer of silica aerogel will simultaneously transmit sufficient visible light for photosynthesis, block hazardous ultraviolet radiation and raise temperatures underneath it permanently to above the melting point of water, without the need for any internal heat source. Placing silica aerogel shields over sufficiently ice-rich regions of the Martian surface could therefore allow photosynthetic life to survive there with minimal subsequent intervention. This regional approach to making Mars habitable is much more achievable than global atmospheric modification. In addition, it can be developed systematically, starting from minimal resources, and can be further tested in extreme environments on Earth today.
ful text: https://www.nature.com/articles/s41550-019-0813-0
Portugal announces Firm Order for the Multi-Mission Airlift KC-390
press release
The Portuguese Government announced today a firm order of five multi-mission airlifters Embraer KC-390 as part of the process to modernize Portuguese Air Force capacities to support national Armed Forces operations and increase readiness in missions of public interest. Deliveries are scheduled to start in 2023. The KC-390 is designed to set new standards for efficiency and productivity in its category while presenting the lowest life-cycle cost of the market. The aircraft can perform different types of military and civilian missions including humanitarian support, medical evacuation, search and rescue and firefighting, while fully meeting the requirements of the Portuguese Air Force, adding new superior cargo and troops transport, aerial delivery and aerial refueling capabilities. “Today is a historic day for the KC-390 Program and I want to thank those who have contributed to the project. This is a very important step to consolidate the aircraft which we believe will become another success for Embraer. The Portuguese KC-390 will meet new interoperability requirements, in the areas of secure navigation, data and voice transmission that will allow the KC-390 to integrate joint operations in multinational alliances in which Portugal is integrated. These requirements, developed in partnership with the Portuguese Air Force, will enable the KC-390 to meet the needs of many other nations around the world.” said Jackson Schneider, President and CEO of Embraer Defense & Security. “The industrial partnership between Portugal and Embraer contributes to the development of engineering and the Portuguese aeronautics industry, representing more than 300 million euros in exports each year and thousands of highly skilled jobs.” Portugal is the largest international partner of the KC-390 Program and its participation in the development and production of the aircraft is recognized as having had a positive economic impact in the generation of jobs, new investments, increased exports and technological advances. The KC-390 has received its Civil Certification from the Brazilian National Aviation Agency (ANAC) in 2018 and is now in full serial production. Entry into service is expected to occur in the 3rd quarter of 2019 with the Brazilian Air Force (FAB), with follow on deliveries to occur throughout the year.
First Boeing P-8A Poseidon for United Kingdom takes flight
PR
The first Boeing [NYSE: BA] P-8A Poseidon for the United Kingdom Royal Air Force (RAF) took off from Renton, Wash. at 10:00 a.m. Pacific on July 12, marking the first flight of this inaugural UK P-8A.
During the 90 minute flight key testing took place before the aircraft touched down and moved to the next phase of preparation before customer delivery, installation of military systems.
UK Ministry of Defence (MOD) and Royal Air Force personnel, along with Boeing P-8 program leaders, were on hand to witness the takeoff and landing of the recently painted aircraft, number ZP801.
“This is a great milestone in the UK P-8A Poseidon’s journey to the UK, as we are one step closer to its arrival in Scotland,” said Air Commodore Richard Barrow, the senior responsible owner for the UK’s P-8A program. “The platform will enhance the UK’s maritime patrol capability with advanced, state-of-the-art technology.”
The RAF P-8A Poseidon fleet will support maritime surveillance, anti-submarine warfare and anti-ship warfare for the UK, and will increase protection of the UK’s nuclear deterrent and Queen Elizabeth class aircraft carriers.
The first of nine P-8As ordered by the UK now moves to the P-8 Installation and Checkout facility in Tukwila, Wash., where mission systems are installed and further testing happens before final delivery to the customer later this year. When the aircraft is delivered it will first fly to U.S. Naval Air Station Jacksonville for additional preparation and training by UK personnel before flying home to the UK. The RAF will take delivery of ZP801 later this year and it will move to the UK in early 2020.
The United Kingdom is one of six international customers for the P-8A Poseidon. As a direct commercial sale, India has received eight of the P-8I variant to date with four more in production. The U.S. Navy is on contract to receive 111 with the potential for additional quantities based on the fleet’s needs. As a cooperative partner with the Maritime Patrol and Reconnaissance Program Office, Australia began receiving their P-8A aircraft in 2016 with eight delivered and four more in production; Norway will begin receiving their five P-8As in 2022; both New Zealand and South Korea have signed agreements with the U.S. Navy to purchase four and six aircraft respectively.
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