mrfox

http://en.wikipedia.org/wiki/Down_and_Out_in_the_Magic_Kingdom An interesting novel set in a future with immortality, lack of scarcity, and how a society might cope (or not)

Cosmonaut Vladimir Komarov died on Soyuz1 due to chute deployment failure. After 18 orbits, Soyuz 1 fired its retrorockets and reentered the Earth's atmosphere. Despite the technical difficulties up to that point, Komarov might still have landed safely. To slow the descent, first the drogue parachute was deployed, followed by the main parachute. However, due to a defect, the main parachute did not unfold; the exact reason for the main parachute malfunction is disputed.[6] [7] Komarov then activated the manually deployed reserve chute, but it became tangled with the drogue chute, which did not release as intended. As a result, the Soyuz reentry module fell to Earth in Orenburg Oblast almost entirely unimpeded, at about 40 m/s (140 km/h; 89 mph). A rescue helicopter spotted the descent module lying on its side with the parachute spread across the ground. The retrorockets then started firing which concerned the rescuers since they were supposed to activate a few moments prior to touchdown. By the time they landed and approached, the descent module was in flames with black smoke filling the air and streams of molten metal dripping from the exterior. The entire base of the capsule had burned through and by this point, it was obvious that Komarov had not survived, but there was no code signal for a cosmonaut's death, so the rescuers fired a signal flare calling for medical assistance. Another group of rescuers in an aircraft then arrived and attempted to extinguish the blazing spacecraft with portable fire extinguishers. This proved insufficient and they instead began using shovels to throw dirt onto it. The descent module then completely disintegrated, leaving only a pile of debris topped by the entry hatch. When the fire at last ended, the rescuers were able to dig through the rubble to find Komarov's remains strapped into the center couch. Doctors pronounced the cause of death to be from multiple blunt-force injuries. http://en.wikipedia.org/wiki/Soyuz_1

A good part of the jets efficiency comes from the effect of ram recovery - great if you already need to go fast, but going fast does mean consuming all that efficient power that has been generated to overcome drag. Another concept that had been developed during the 50s to improve the expansion ratio of the piston is the power recovery turbine in turbo-compound engines - using the piston exhaust energy to drive a turbine to drive the propeller - pretty much the exact opposite of a motorjet! Most direct current electric start motors today are small and only drive the high pressure turbine, and only up to around 30 percent. To reduce lag, you would need to drive the much more massive low pressure turbine/fan assenbly, and accelerate all that to 100 percent, so they would need to be massively overbuilt. I think we are in agreement that the modern turbine's niche is pretty secure.

Turbines for mobile applications are also very under-expanded - trading efficiency for weight. Stationary applications generally incorprate some sort of exhaust regeneration to increase expansion and heat recovery. Quite a few modern pistons increase their expansion ratio beyond its compression ratio using miller or atkinson cycles - increasing the stroke while delaying the closing of the intake valve.

Tried this at Ferrari world, the dof was very limited and it did not feel very realistic. - - - Updated - - - http://www.flightexperience.com/ You can rent these fixed based sims by the hour.

Afterburners are not limited by the amount of oxygen - they are temperature limited - just like the motorjets were. But since an afterburner is just a nozzle, they can be built to tolerate much higher temperatures then a loaded, rotating turbine disk... just like the limitation the motorjet was trying to work around. So in a way, the afterburner is what really became of the motorjet. I have never thought of it quite this way - very interesting!

Piston diesels are actually more efficient compared to gas turbines, because their compression ratio is independent of rpm, and their intermittent combusion allows less expensive materials to be used due to lower steady state temps Their big drawback is their power to weight ratio.

But imagine a world/situation where high temperature alloys are in short supply. Given the aerodynamics and composites avlb today - you can make a reasonably fast aircraft driven by a ducted fan that is powered by a recriprocating engine. Or electricity for that matter. No need for additional fuel injection after the compressor/fan.

Motorjets was a workaround due to 2 technological limitations of its day; 1- the lack of high temperature/high strength materials to construct the turbine, and 2- material and aerodynamics for efficient, large diameter fan blades.

How about a balloon for a low cost first stage?

As a reference, this is the only other amateur rocket so far to make it up to "space". http://www.the-rocketman.com/go-fast.html

Where 3D goggles are really going to shine is in remote operated, camera equipped drones (UAV) operations. A huge and common problem for drone operators today is the total loss of situational awareness - often the phrase "where am I? And what did I just hit?" come to mind. If fact, if the drones mission is survalliance/reconnaissance, it would provide the most natural user interface if combined with a hovering/rotary wing craft, and control algorithms to emulate a "mouse look" environment.

The biggest difficulty will be interacting with other human vehicles and pedestrians. Autolands are rarely done - not only because of the higher workload, but because greater tolerances are required - the sensitive approach area must be kept completely clear of traffic, and the seperation between aircraft greatly increased over visual operations. The handling capacity of the airfield dramatically decreases. Autolands are generally only done when visibility precludes normal visual landings, and for crew/aircraft certification/currency.

Its not where they are headed - but its where they are now. The step over to full autonomus control with no realtime human backup - and no human to take responsibility immediately when the automation goes wrong, will be a huge one. One of the biggest challenges is whether a system is fail-safe - an automated subway system can simple put the brakes on and stop, if it falls outside what the system consider "normal" parameters, and be confident it will safely come to a stop without many issues, because it is on rails. And because all automated train systems today are segerated systems, they wont be putting any other traffic - train or human, at risk either. To be able to prove statistically that a driverless car, at speed and in mixed traffic, can "always" provide a safe outcome for everyone if anything goes wrong at speed, is a challenge and responsibility that current technology is not quite ready for, and the reason they get "slammed" by the regulators. Airplanes, even more so, as they go much faster and can't stop in midair.

I have no doubts that the evolution of automation in transportation will continue towards full automation. My opinion is only that the readiness and reliability of the technologies required are quite a bit beyond the current state of the art, and it will be some time before such a reality can be realized. One of the big issues, as you correctly identified, is the mixing of automated traffic with human controlled vehicles. Air traffic is by nature free flowing, analogous to vehicular and ship traffic, and crisscross from branch to branch. Unlike an automated subway line, where you can built a isolated system that is segregated from non-automated traffic, it would be extremely difficult, and operationally and economically unfeasible, to set aside space for automated aircraft where they won't interfere with human controlled traffic. Yes, google is testing driverless cars, but a human driver is always behind the wheel, ready to take over at a moments notice. So really it is actually only catching up to the level of automation that already exist in current airliners today during low visibility operations. The reality today is that when airports today go into low visibility operations and automatic approaches and landings are being conducted, the operations rate dramatically reduces to cater for the increased separation requirements.

https://youtu.be/gMfuLtjgzA8?t=13m29s Interesting relevant bit from a talk by Andy Weir, author of "The Martian", at 13:30. He did it via numeric iteration.

You are looking for a brachistochrone trajectory using a torch ship.

From what I understand, is that with current technology, a computer still cannot be aware of a problem that it was not programmed to diagnose, or "improvise" a new solution to a problem that has not been considered in its design. What the future may hold? Well that's in the realm of speculation. Would an AI that has the capacity to "foresee" a situation with a sub-optimal outcome for the humans - be required know and understand the same "motivations" humans have in the first place? - - - Updated - - - Not overly complex, just designed in a "dumb" way to have altitude and speed constraints at almost every waypoint - a situation that was not considered when the 747 FM was designed. Airport is Seoul Incheon - ICN/RKSI.

EFF 09 DEC 14: CAUTION: 747 FM DATABASE RNAV STARS KARBU 1N/GUKDO 1N/OLMEN 1N/BIKSI 1M EXCEED STAR DESIGN MAX WPTS DUE MULTIPLE ALT/SPD CONSTRAINTS AND MAY CAUSE DUAL FM FAIL. DO NOT ACCEPT THESE RNAV STARS. OTHER USEABLE STARS GUKDO 1A AND MAKSA 1M. KOREA CAA INFORMED BY BOEING AND AIRLINES. STAR REDESIGN PENDING. Not funny at all when the crew found out for the first time on approach. Don't see Boeing going out of business over this anytime soon either.

Only because the list of crashes that would've been caused by computer errors, but averted by human intervention, is not public knowledge - they exist only as internal safety memos - for corporate image reasons. For example - the amount of errors that comes up everytime an airline navigation database gets updated (every 28 days) is often downright scary. Our most recent database update had an error that "crashes"(ie fails) both flight management computers entirely every time a particular approach at a certain airport was loaded - which means losing most navigation and automation functions instantly. Other times an error is more insidous - ie a wrong altitude - but the results can be just as deadly without a human preforming a "sanity" check in realtime.

Specific energy (MJ/kg) Kerosene 46 Gasoline (petrol) 44.4 Energy density (MJ/L) Kerosene 37.4 Gasoline (petrol) 32.4 Its inferior to RP1 on both counts of weight and volume.

The thickness of the atmosphere varies with latitude - thickest over the equator and progressively thinner towards the poles.

Or perhaps, our earth being over 4 billion years old, and yet our civilization has merely existed in the last blink of an eye, other civilizations have already visited eons ago and are now long gone.

Shepherds role, when all automated systems are functioning normally, was mainly to provide a running commentary on the onboard systems. Given the limited bandwidth of the instrumentation of the day it was useful - he can provide realtime prioritization of the readings. Obviously, his main-main role was being the test-subject.

https://www.youtube.com/watch?v=FG-0NExds90