mrfox

To shed a bit of relevance to the difference in risk levels between test flying and the finished products - note that both the Gulfstream G6 (a plaything for the rich, just like VG), and the Airbus A330 (one of the most sucessful and prolific large commercial jets today) both suffered fatal crashes with total hull loss during flight testing.

It might not be intuitive, but as a piece of minimalist engineering it was art at its finest - and its simplicity was absolutely necessary, given the weight and computing limitations of its time. Not to mention this sort of keyboard interface was at its infancy at the time - most computers were still switch/punchcard driven when this was designed. Its interface is actually pretty damn logical in comparasion.

http://www.capcomespace.net/dossiers/espace_US/apollo/apollo13/transcript.htm#mcc5

Or... in the case of apollo 13, they had to do a mid-course correction burn using their lander engine (the one that hasnt been damaged by the previous explosion), with no nav computer because they needed to conserve battery power for re-entry - just a stopwatch, a mark on the window, a big start/stop button and lots of jockeying on the joystick - just like KSP!

http://www.switched.com/2009/06/22/four-nerve-racking-space-shuttle-launch-aborts/

http://www.spacedaily.com/reports/China_Sends_Life_to_Moon_999.html

A robotic mission can do more per dollar, but a combined manned/robotic mission would provide the maximum overall return, full stop, given the time constraint. The crew won't be there to do the lifting and grunt work, but to operate the probes and machinery in real time, make decisions, provide feedback, do repairs and modifications, even create tools/machinery/experiments on the fly - all the sorts of other things that limits the operational flexibility of fully robotic missions of today.

Never? We've only been a space faring species for just over 50 years. This encounter is 50+ years away. Try to open your mind up a little to discussing possibilities rather then shut out ideas with dogmatic trivia. Transmission has not been an issue thus far, because we have never gone so far before. A manned mission can accomplish more given the limited time of the encounter. It would certainly cost a hell of a lot more, but thats more of a political hurdle than an engineering or scientific one.

One upping that one would be the launch/abort of soyuz 18a, which did 21.3Gs during the abort maneuver!

Its just that with a 10 hour transmission delay (one way) at point of closet approach, scant data on the properties of the body, and a limited window of time for study, it does scream for sending someone out there, an operator who can operate autonomously, able to make decisions on the fly, and and work at a decent pace. Perhaps this is the one mission where the orion drive needs to be resurrected for.

Given that this is a "once in a civilization" opportunity, it would be interesting to discuss the likelyhood, benefits and obstacles of a manned mission.

Hence you are aware of the razor thin performance margins of current aerospace tech, and thus, the issue of using high weight/low energy fuel in this application. There are specific applications which you can justify such a system - something where there is a high weight cost for transporting the power plant, but a zero to nil transport cost for getting the fuel - generators for remote mining camps for instance, where everything needs to be flown in, but low grade fuel is avlb locally.

This then becomes a chicken/egg problem. The reason jet aircraft cruise at such speeds is because they are powered by jets. The cost of a jets inefficiencies are offset by the cost of time it saves from high speed travel. This balance is not static - Notice in the past decade the resurgence of turboprops for short/medium range flights because of the increase of the price of fuel. If fuel cost continue to increase it would not be a surprise if ideas such as unducted fans with higher propusive efficiencies are reintroduced, bringing the long range cruise speeds down from where it is today.

Jet engines are pretty inefficient thermally, the reason they are used in aircraft is because they are low weight. Using a low specific energy (high weight) fuel defeats the purpose.

Back on topic... Some practical issues rgd BWB in commercial service I can think of are: Wing fineness and aspect ratio - if your aircraft has a thick wing, its chord and span needs to be scaled up also, otherwise the wings performance will be sub-optimal. You end up with a massive design that does not fit any of the current runways and airport facilities avlb. Loading, center of gravity, center of rotation issues - Most BWB designs lack a tail, which makes load balancing extremely critical. Same with lateral balance - You will need to load very symetrically and wont be able to tolerate much imbalance. In a passenger setting this means few to no movement can be tolerated in flight. There is also the issue of vertical accelerations experienced during roll manuevers by passengers on the outer extremes of the cabin. As they are so far out from the center of rotation, it will be quite the nauseating and uncomfortable ride - made worse by the lack of outside references - every turn will be a barf fest. The lack of a tail also mean that the wing will not be able to take full advantage of the high lift devices typically used in most commercial aircraft for takeoff and landing - which means that its runway requirements, comparaed to an aircraft of similar performance, at anywhere near comparable weights, will be extraordinary (in a bad way).

An answer from Andy himself: http://youtu.be/gMfuLtjgzA8?t=32m30s

The OTRAG (Orbital Transport und Raketen AG, or Orbital Transport and Rockets, Inc.), was a West German design from the 1970s. Modular CPRUs (Common Rocket Propulsion Units) - Simple, steel cased pressure-fed rockets with almost no moving parts. Bundled into clusters of varying sizes, depending on mission payload And staging requirements Over 6000 static tests firings were done, with total burning time approaching one million seconds. And 14 suborbital test flights. In terms of reliability, the CRPU was human-rated and had a confidence level higher than 6-sigma. Such a shame it was shut down, mainly due to the political climate of its times.

My understanding is that the effects of time dialation are relative to each observer - meaning that both the observer from outside the black hole, and the observer falling in, should observe each others time slow down. Heres a great video by Eugene Khutoryansky explaining GR in laymans terms

Documentaries often use footage of a Saturn V launch, and one of the most used pieces shows the interstage between the first and second stages falling away. This footage is usually mistakenly attributed to the Apollo 11 mission, when it was actually filmed on the flights of Apollo 4 and Apollo 6.[13] A compilation of original NASA footage shows the jettisoning of the first stage (S-IC) and the interstage, filmed from the bottom of the second stage (S-II), both from Apollo 4.[14] This is followed by footage of the separation of an S-IVB second stage from the first stage of a Saturn IB. The glow seen on the jettisoned stages is due to the hot, invisible hydrogen-oxygen flames of the J-2 engines used by the S-II and S-IVB.[13] The footage also shows the more conspicuous plumes of the solid ullage motors as they pull the stages apart before the main engines are fired. The cameras ran at four-times normal speed to show the events in slow motion.[14] The camera capsules were jettisoned soon after the first stage separation and though at about 200,000 feet (61*km) in altitude, were well below orbital velocity.[13] They then reentered the atmosphere and parachuted to the ocean where they floated waiting for recovery. Both S-II cameras from Apollo 4 were recovered so that there is footage from both sides of the vehicle.[1] http://en.wikipedia.org/wiki/Apollo_4#Saturn_V_cameras

Here she is, engine off, in formation with a F-104, gliding in for a landing Kinda brings the topic full circle - even a brick can glide!

Some other examples of airplanes with extremely poor glide ratios, yet are more than capable of landing with no engine power: F-104: Glide ratio - appox 5 :1 X-15: Glide ratio - appox 4:1 X-24B: Glide ratio - appox 2.5:1

There is a big difference between humans and the other animals mentioned - between humans, there is an implicite (or explicite) agreement for us not to eat each other. We cannot make the same compact with dolphins/apes/etc. Along this same line of thinking, there is a distinct difference between eating dogs/cats/pigs domesticated as pets (trained not to harm their human owners - hence, a mutual compact exists) vs those same animals bred for food.

http://en.wikipedia.org/wiki/Biomagnification

A negative of a carnivourous diet is that you have a greater exposure to to all the dieseases, poisons, chemicals and heavy metals ingested downstream in the foodchain.