Quote from: R7 on 03/01/2016 11:02 amIMHO the quiet boom choice was strange when they seemed to emphasize greener stuff. Boom or no boom supersonic flight causes a lot worse passenger miles per gallon figures than conventional speeds. Or passenger miles per kWhr too if one dreams of electric flight. I fail to see how trying to enable very expensive overland supersonic trips for a few HNWIs is greener act. Concorde was economic flop despite heavy subsidies and investment write-offs by France and UK.I think those are all legitimate points (indeed, I have heard them made by a very smart top aeronautical scientist who works for one of those companies that puts engines on big jets).And a legitimate related point is why did NASA choose this particular technology to advance at this time? Well, I don't know the specifics of the decision, but I am familiar with some of the background. Several years ago an independent study recommended that NASA start conducting more flight research (meaning actually flying aircraft). http://www.nap.edu/catalog/13384/recapturing-nasas-aeronautics-flight-research-capabilitiesLook at the findings and recommendations in the summary there. The options included environmentally responsive aviation, low boom supersonics, and hypersonics. Hypersonics is a bugaboo, with other issues. I think that low boom supersonics is something for which there is clear industry interest, although it is a niche. <snip>
IMHO the quiet boom choice was strange when they seemed to emphasize greener stuff. Boom or no boom supersonic flight causes a lot worse passenger miles per gallon figures than conventional speeds. Or passenger miles per kWhr too if one dreams of electric flight. I fail to see how trying to enable very expensive overland supersonic trips for a few HNWIs is greener act. Concorde was economic flop despite heavy subsidies and investment write-offs by France and UK.
I could also see military applications for quiet sonic booms. A supersonic bomber or tanker/transport flying over "denied territory", on a strike mission or troop deployment for example.
But it would still likely have a big radar signature.
I did not watch the Monday press conference/announcement, but did they say anything about initiating future flight projects? Are they perhaps thinking about starting a new one each year for the next several years?
Lockheed is pursuing the HWB concept with funding support from the U.S. Air Force Research Laboratory (AFRL) under its Revolutionary Configurations for Energy Efficiency program, which ends in 2017. The company will complete a study for AFRL of a manned HWB demonstrator this fall, he says. A commercialization study for NASA, looking at a freighter variant, will finish around the same time.NASA has unveiled budget plans to fly a 50%-scale hybrid wing body demonstrator after 2020 as the second in a proposed series of large-scale X-planes. To date, the agency’s definition of HWB has been synonymous with Boeing’s Blended Wing Body configuration, but Lockheed plans to propose its HWB concept, and NASA says selection of the X-plane will be an open competition. “We do qualify to play in the HWB plans, and are working with NASA to make sure that we do,” says Hooker.
Quote from: Bubbinski on 03/02/2016 06:34 pmI could also see military applications for quiet sonic booms. A supersonic bomber or tanker/transport flying over "denied territory", on a strike mission or troop deployment for example.But it would still likely have a big radar signature.
Quote from: Blackstar on 03/02/2016 08:33 pmQuote from: Bubbinski on 03/02/2016 06:34 pmI could also see military applications for quiet sonic booms. A supersonic bomber or tanker/transport flying over "denied territory", on a strike mission or troop deployment for example.But it would still likely have a big radar signature.Yeah. So you are going to lit up the ground surveillance and target acquisition radars like beacons for the Anti-Radiation missiles of the strike package to home in on. Will be interesting.However quiet supersonic strike aircraft will be useful to take out targets without radar capability. Since the target will have little or no warnings from picket observers listing for noise from approaching aircrafts.
There are a number of different aspects to this project which I'd summarize as:-technical feasibility-regulation (how much noise is allowed)-commercial interest and feasibilityNASA is tackling aspects of the first two, but they're complex. For instance, if they can prove the concept on this test vehicle, can that be scaled up to a larger vehicle that can carry passengers? And the regulation is a multi-pronged issue too, because the noise will vary based upon altitude, humidity, other atmospheric issues. I heard a NASA guy explain how he had been on the ground during a supersonic flyover by a military jet and never heard a sonic boom at all because the atmosphere had mitigated it. So there's a lot of factors that go into how the noise is detected and even defined.
Right. I think this is why they went with an actual piloted vehicle instead of a more subscale robotic one.A crewed vehicle makes this a lot more /real/ to commercial interest and investors. It's also a camel nose under the tent of regulators, as you can start doing real cross-country demo flights.
Quote from: Robotbeat on 06/15/2016 04:15 pmRight. I think this is why they went with an actual piloted vehicle instead of a more subscale robotic one.A crewed vehicle makes this a lot more /real/ to commercial interest and investors. It's also a camel nose under the tent of regulators, as you can start doing real cross-country demo flights.They have already done subscale camel noses on the F-5 and F-15. Time to go larger.