mrfox

Seems my info is out of date... https://www.businessinsider.com/antarctica-greenhouse-dlr-german-aerospace-center-2017-9#the-135-square-foot-greenhouse-can-grow-all-sorts-of-produce-indoors-harvesting-food-outdoors-is-impossible-in-antarctica-due-to-its-endless-winters-2 Antarctica's nonstop winters make it impossible to grow food outdoors. Fruits and vegetables are instead shipped long distances from overseas, just a few times per year. But in 2017, engineers at the German Aerospace Center (GAC) built a high-tech greenhouse that will allow Antarcticans to harvest produce. The farm can grow food year-round for researchers at the Neumayer III polar station on the Ekstrom Ice Shelf. The team just completed its first harvest, the AP reports. Called the Eden-ISS, the greenhouse exists inside a climate-controlled shipping container. It relies on a technique called vertical farming, in which food grows on trays or hanging modules under LEDs instead of natural sunlight.

ISRU, ie farming, is currently not allowed in current Antarctic operations due agreements as a part of the Antarctic treaties - in order to prevent introduction of invasive species and environmental pollution. It is not due to technical limitations.

Realistically, any initial iteration of a Mars colony will be a research base. And I’d imagine it would resemble Mcmurdo station in Antarctica, except with a lot more life support infrastructure.

From the golden age of KSP

Nuclear salt water rockets have nothing to do with salt water. It’s “nuclear salt” + “water”. Have a read of this list and come back. Your ideas are pretty incoherent at the moment, as you seem to be taking a few select buzz words from various concepts, and then making the rest of it up as you go along. http://www.projectrho.com/public_html/rocket/enginelist.php

Good catch with the picture and a poor misleading example on my part. you are correct on the 321 ceo and the initial 321 neo. It is on the latest 321 neo XLR that had the flap design change. Same thing for the 747 for its -8 update - triple slotted to double and single slotted.

I think it’s a combination of better aero fluid modelling during the design phase, coupled with digital fly-by-wire that allows for more complex permutations of control surface positioning in flight. In a nutshell - computers. There are some pretty big downsides to swing wings too... weight and mechanical complexity being the major one. Another is poor distribution of the center of pressure of the wing, resulting in high trim drag during supersonic flight. A similar thing has happened in recent years that has seen the demise of triple and double slotted flaps and the elimination of active CG control - both replaced by better designed and actively positioned flaps brought about by better computers. Another variation on the variable geometry theme is the XB70, another elegant design with downward folding wingtips that better optimised wing area, longitudinal trim, increased vertical tail area for lateral stability and provided compression lift for Mach 3 cruise.

The layout bears some semblance to the final proposed design of the (cancelled) Boeings 2707 SST from the 1960s. The initial version had variable sweep wings too - which would’ve been great for field performance. Its a shame variable geometry fell out of vogue - it really made for some good looking airplanes.

Well they did mention that the gen-set was going to be used for repositioning the plate in the event of a “dud” round... but yeah... certainly sounds like a nuclear bike shed design.

Re. The original blog post Why go through all that trouble with converting linear motion into rotary motion, if all you want is a electrical generator/motor set? Its like they’ve never heard of linear generator/actuators...

With air cooled piston pusher designs, the persistent problem was engine cooling - especially at low speeds. Often the rear mounted engine would overheat during climb out, or during extended ground operations.

Sorry... pet peeve. It’s damping. Dampening is adding moisture - making something wet. carry on...

Would it really be a large twin like a 777 vs a quad? With 3 or 4 engines, an engine failure allows enough margin for the mission to continue (fail operational), vs a most likely mission abort in the case of losing an engine in a twin. Of course, the 4 engine P-3 is being replaced by the twin P-8. KC-135s by KC-46s, and so on. So I guess it’s no longer seen as such a big deal to go with 2. I must be getting old. The latest gen of aircraft being fielded - both civil and military, just doesn’t seem generate as much intrigue nor excitement as they used to.

Agreed that an aircraft designed to drop bombs will be better suited than something modified. I should rephrase my question as one pertaining more to the actual physical capability required of an aircraft of a C17s vintage to fly a B52s mission profile... Or perhaps better phrased - how would a B52 be designed today using current tech?

Good point regarding the noise deadline. I imagine the incremental benefits of going from a 1950s gen to a 1990s gen engine is far greater than from the 90s to today - both with regards to noise and operating cost. The B52 re-engine brings up an interesting question - what exactly is a B52 capable of doing that couldn’t be done by retrofitting equipment to something more modern like a C17?

Prior to the 2000s, re-engining older airframes was a common practice to extend their useful economic life. Any thoughts as to why this practice has fallen out of favour?

Not both at the same time, although some in our test and engineering dept do. It’s a nightmare to keep current in multiple types, legally and practically. The Airbus control system would be another interesting discussion topic on this thread. In essence, it’s an attitude stabilisation system - like having the KSP SAS on full time. Its origins can be traced back to both the space shuttle FBW control laws, the CWS mode on older analog(and a few modern digital)autopilots, and all the way back to WWII formation bombing autopilots. https://ntrs.nasa.gov/citations/19760024058 https://www.ima-usa.com/products/original-wwii-u-s-b-17-flying-fortress-c-1-autopilot-formation-control-stick-assembly?variant=12460921192517

Well, one place it felt distinctly different between the two is during crosswind landings. One of the biggest concerns during the touchdown, derotation and rollout in high crosswinds is the possibility of engine pod strikes. A floppy wing makes engine pod clearance very tricky to judge. Although the Airbus control laws makes flying with crossed controls somewhat unintuitive, once I got my head wrapped around the logic, I ended up feeling more comfortable in on the bus compared with their Boeing counterparts.

The B52 was exactly what came to mind when I thought of this subject. But in the BUFF’s case - wing flex reduces anhedral - which to me seems be be such an elegant design outcome. This might be anecdotal, but Boeing aircraft had always looked and felt floppier to fly compared to an equivalent Airbus. The A350s wing - also carbon - does not flex nearly as much as the 787s.

Dihedral and anhedral had always seems to me to be such an inefficient way to generate stabilising moments. In this age of computers and fly by wire, can’t the (de)stabilising effects be generated artificially via control systems design? IE larger control surfaces and gains and feedback loops actively modified on the go to obtain the desired response? Is it a certification issue or is it a basic aerodynamics issue? On the same note - why so much dihedral from wing flex on the 787 compared to other current designs?

Transonic buffeting effects had also been widely reported by pilots of propeller-driven Allied fighters including the Supermarine Spitfire, P-38 Lightning, P-47 Thunderbolt and P-51 Mustang, aircraft that were known to have top diving speeds of less than 0.85 Mach (although one Spitfire was measured at 0.92 Mach). Allied fighter pilots reported seeing supersonic shock waves and popped rivets during dives as the high-speed air rushing over the wing exceeded Mach 1 even though the forward airspeed of the overall aircraft was well below that speed. https://en.m.wikipedia.org/wiki/Hans_Guido_Mutke

My poor brain can't seem to rotate the cross-section axis to an orientation that makes sense. All I can see is a bunch of your above diagrams, with their normal shocks, stacked laterally and offset by sweep angle. Which orientation do I need to be looking from to see the wedge geometry that creates the oblique shock? Edit: Well I’m going to try answer my own question since the wing platform is the obvious wedge...? In this orientation, how would the normal shock from a straight wing look? How would they both look from an overhead prospective of the two geometries, and its associated shockwaves? I’m still somewhat unclear as to how this all looks

Would you mind doing a treatment on wingsweep? Why does the airflow behave as if it is travelling in a direction normal to the leading edge? This never made any sense to me - as spanwise flow should instead be directed outwards and back towards the tips. Why can this component be ignored, when the actual flow of air particles and it’s associated interactions and energies are actually going in this direction? What happens to the analysis at the wing root, tips, fences and other obstruction? This has always been a topic that I could not get comfortable around explaining. I can regurgitate it, but lack an intuitive understanding. Any input would be deeply appreciated.

http://www.projectrho.com/public_html/rocket/mining.php#bottleneck TL;DR - Phosphorus from mars