5 février 2021 | International, Aérospatial, Naval, C4ISR
Researchers at Stanford University have developed a new type of sonar to overcome the previously insurmountable problem of seeing underwater from the air. Sound does not travel easily between air and water: there is a 65-decibel loss, which means roughly a million-fold decrease in intensity, making it makes it virtually impossible to pick up sound reflections from the air. The new technology can map the seabed and potentially detect mines, submarines and other underwater targets from aircraft.
Currently, the only ways of using sonar from aircraft are sonar buoys (sonobuoys) dropped into the water, or dipping sonar lowered to the sea surface from a hovering helicopter. The helicopter cannot move while using dipping sonar, so it has to check one spot, raising the sonar, fly somewhere else, lowering the sonar again, and so on.
By contrast, the new Photoacoustic Airborne Sonar System or PASS, developed at Stanford with funding from the U.S. Navy, will work from a moving aircraft.
“Our vision of the proposed technology is to capture images continuously as the airborne vehicle flies over the water,” Stanford researcher Aidan Fitzpatrick told Forbes. “Similar to how synthetic aperture radar systems or in-water synthetic aperture sonar systems work today.”
https://www.forbes.com/sites/davidhambling/2021/02/04/new-sonar-sees-underwater-from-aircraft/
17 décembre 2023 | International, Terrestre
The designation is a recognition that SPACECOM meets the criteria to conduct its mission to deliver a range of space capabilities to military users.
27 janvier 2020 | International, Aérospatial
By: Sebastian Sprenger Correction: A previous version of this story misidentified the cost increase to Britain's Protector acquisition program. The program is said to now cost an extra £325 million, with £187 million of that attributed to a delivery delay. LONDON — The British Defence Ministry's top civilian has identified in a letter to lawmakers the reasons why a drone acquisition program has experienced a near 40 percent hike in costs. The Ministry of Defence decided to delay by two years the delivery of 16 General Atomic Protector RG Mk1 drones to replace the Royal Air Force's MQ-9 Reaper fleet, the letter to Parliament's Public Accounts Committee said. Stephen Lovegrove, the ministry's permanent secretary, cited that decision as the main reason for the £325 million (U.S. $427 million) cost increase to the program, as £187 million of that could be attributed to the delay. “The cost growth and time delay to the program imposed in July 2017 were outside of program tolerances but were the result of the need to ensure the affordability of the overall defence program,” Lovegrove wrote in his letter. The MoD is currently in negotiations with the U.S. over a deal to build the first three of the 16 Protectors scheduled to be purchased for the RAF. The final number of vehicles on order could eventually expand beyond 16 — subject to the MoD's fragile finances in the coming years unless defense gets a sizable increase in the Conservative government's next budget round due later this year. The letter was sent Nov. 5 but has only recently been made public. Lovegrove detailed further causes of the cost increase rise in the drone program, which was expected to cost £816 million when it was approved by the MoD in 2016. Aside from the increased costs caused by the delay, the letter said that the fall in the value of the pound against the dollar accounted for £50.8 million of the price rise, and a new primary sensor cost another £64 million. Other unspecified program costs accounted for a further £23 million. The pound has firmed up against the dollar a little since the Conservative Party won the general election in December, which may lessen the impact of increased costs for the moment. The new primary sensor investment involves provision of an improved electro-optical and infrared sensor. The letter said the investment was to avoid future obsolescence issues. Consideration is still being given to the purchase of what is known as a “due regard air-to-air radar” designed for vital detect-and-avoid duties on the platform. Protector, which is the British name for its version of the new General Atomics MQ-9B SkyGuardian, is scheduled to achieve initial operating capability in November 2023, the letter read. The vehicle will replace the current fleet of MQ-9 Reapers, which the RAF has operated almost constantly during the last few years over Afghanistan and the greater Middle East. Lovegrove said the MoD had compared Protector with other options to meet the requirement but the General Atomics platform remained the best value for money. “A comparison was made between: developing a new remotely piloted aircraft system capability (either collaboratively or nationally); procuring the current Reaper Blk 5 (as used by the US Air Force and others); and procuring Protector,” he said. “This concluded that procuring Protector represented best value for money, as its higher performance meant that the operational task could be delivered by procuring fewer air vehicles. The 2-year delay and resultant cost increase have not undermined this value for money case ... it remains affordable despite the cost growth,” the permanent secretary added. Lovegrove said the biggest problem for the Protector program was not the platform itself but the availability of trained crew in the run-up to initial operating capability. “The most significant risk to the Protector program is the RAF's ability to generate and sustain the volume of trained personnel necessary to assure IOC in Nov 2023. The Protector work force builds on the current Reaper force; training and retaining sufficient remotely piloted aircraft system crews has historically proved challenging and is being closely monitored,” the letter said. The Protector is expected to fly longer and hit harder than the Reaper. The UAV will also fly in nonsegregated airspace in places like the U.K . in September, the MoD and General Atomics signed a significant deal to complete the test and evaluation activities required to fly the system in civil airspace. The first test and evaluation aircraft is due to be delivered next year subject to the successful completion of the production contract. An initial production deal is currently in negotiation, with aiming of inking a deal in the next few months. In a first for the system, the SkyGuardian version of the medium-altitude, long-endurance drone flew across the Atlantic Ocean in July from Grand Forks, North Dakota, to RAF Fairford in England. The flight covered 3,760 nautical miles in 24 hours and 2 minutes. https://www.defensenews.com/unmanned/2020/01/24/british-defence-ministry-reveals-why-a-drone-program-now-costs-245m-extra/
22 avril 2020 | International, Naval
By: David B. Larter WASHINGTON – An internal Office of the Secretary of Defense assessment calls for the Navy to cut two aircraft carriers from its fleet, freeze the large surface combatant fleet of destroyers and cruisers around current levels and add dozens of unmanned or lightly manned ships to the inventory, according to documents obtained by Defense News. The study calls for a fleet of nine carriers, down from the current fleet of 11, and for 65 unmanned or lightly manned surface vessels. The study calls for a surface force of between 80 and 90 large surface combatants, and an increase in the number of small surface combatants – between 55 and 70, which is substantially more than the Navy currently operates. The assessment is part of an ongoing DoD-wide review of Navy force structure and seem to echo what Defense Secretary Mark Esper has been saying for months: the Defense Department wants to begin de-emphasizing aircraft carriers as the centerpiece of the Navy's force projection and put more emphasis on unmanned technologies that can be more easily sacrificed in a conflict and can achieve their missions more affordably. A DoD spokesperson declined to comment on the force structure assessment. "We will not comment on a DoD product that is pre-decisional,” said Navy Capt. Brook DeWalt. The Navy is also working on its own force structure assessment that is slated to be closely aligned with the Marine Corps' stated desire to become more closely integrated with the Navy. Cutting two aircraft carriers would permanently change the way the Navy approaches presence around the globe and force the service to rethink its model for projecting power across the globe, said Jerry Hendrix, a retired Navy captain and analyst with the Telemus Group. “The deployment models we set – and we're still keeping – were developed around 15 carriers so that would all fall apart,” Hendrix said, referring to standing carrier presence requirements in the Middle East and Asia-Pacific. “This would be reintroducing reality. A move like this would signal a new pattern for the Navy's deployments that moves away from presence and moves towards surge and exercise as a model for carrier employment.” A surge model would remove standing requirements for carriers and would mean that the regional combatant commanders would get carriers when they are available or when they are needed in an emergency. With 9 carriers, the Navy would have between six and seven available at any given time with one in its mid-life refueling and overhaul and one or two in significant maintenance periods. The net result would be significantly fewer carrier deployments in each calendar year. The assessment reducing the overall number of carriers also suggests that the OSD study didn't revamp the Carrier Air Wing to make it more relevant, Hendrix said. Esper has taken a keen interest in Navy force structure, telling Defense News in March that he had directed the Pentagon's Office of Cost Assessment and Program Evaluation (CAPE), along with the Navy, to conduct a series of war games and exercises in the coming months in order to figure out the way forward toward a lighter Navy, but said any major decisions will be based around the completion of a new joint war plan for the whole department, which the secretary said should be finished this summer. “I think once we go through this process with the future fleet — that'll really be the new foundation, the guiding post,” Esper told Defense News. “It'll give us the general direction we need to go, and I think that'll be a big game changer in terms of future fleet, for structure, for the Navy and Marine Corps team.” When it comes to carriers, Esper said he saw a lot of value in keeping carriers in the force structure, and that it wasn't going to be an all-or-nothing decision. “This discussion often comes down to a binary: Is it zero or 12?” Esper said. “First of all, I don't know. I think carriers are very important. I think they demonstrate American power, American prestige. They get people's attention. They are a great deterrent. They give us great capability.” Revamped Surface Fleet The OSD assessment also calls for essentially freezing the size of the large surface combatant fleet. There are about 90 cruisers and destroyers in the fleet: the study recommended retaining at least 80 but keeping about as many as the Navy currently operates at the high end. The Navy's small surface combatant program is essentially the 20 littoral combat ships in commission today, with another 15 under contract, as well as the 20 next-generation frigates, which would get to the minimum number in the assessment of 55 small combatants, with the additional 15 presumably being more frigates. The big change comes in the small unmanned or lightly manned surface combatants. In his interview with Defense News, Esper said the Navy needed to focus integrating those technologies into the fleet. “What we have to tease out is, what does that future fleet look like?” Esper said. “I think one of the ways you get there quickly is moving toward lightly manned [ships], which over time can be unmanned. “We can go with lightly manned ships, get them out there. You can build them so they're optionally manned and then, depending on the scenario or the technology, at some point in time they can go unmanned. “To me that's where we need to push. We need to push much more aggressively. That would allow us to get our numbers up quickly, and I believe that we can get to 355, if not higher, by 2030.” The Navy is currently developing a family of unmanned surface vessels that are intended to increase the offensive punch for less money, while increasing the number of targets the Chinese military would have to locate in a fight. That's a push that earned the endorsement of the Chief of Naval Operations Adm. Michael Gilday in comments late last year. “I know that the future fleet has to include a mix of unmanned,” Gilday said. “We can't continue to wrap $2 billion ships around 96 missile tubes in the numbers we need to fight in a distributed way, against a potential adversary that is producing capability and platforms at a very high rate of speed. We have to change the way we are thinking.” Aaron Mehta contributed to this report from Washington. https://www.defensenews.com/naval/2020/04/20/defense-department-study-calls-for-cutting-2-of-the-us-navys-aircraft-carriers/