Racescort666

Don't forget about the deliberate misinformation campaign during the F-117 operations: https://foxtrotalpha.jalopnik.com/the-f-117-stealth-fighter-program-actually-had-a-klingo-1759842067

This isn't really the place to discuss it but I suspect the semi unveil will be rather underwhelming. If I had to guess, it will be a 62k GVWR truck with 2500-4000 lbs of batteries if they stick with the 200-300 mile range target. It will probably be intended for city delivery or regional haul since line haul trucks generally need more range than that and a 4+ hour charge time for that much battery will likely be unacceptable downtime for a line haul truck.

Looks like they were having a bit of a shimmy from the left gear around 2:00

I had to look this up and it was something that was mentioned in a PBS special that came out recently. http://www.businessinsider.com/voyager-kitchen-aluminum-wrap-radiation-short-circuit-2017-9

Kind of related to concrete/cement/steel rebar: carbon fiber composites are extremely susceptible to galvanic corrosion. Without protection, aluminum inserts degrade very quickly. http://www.boeing.com/commercial/aeromagazine/aero_07/corrosn.html

I think maybe the better question is: what is the power requirement when you cross over from an RTG (decay or criticality) to something like a closed cycle gas turbine (brayton cycle) power generator. RTGs still require a temperature differential and I'd imagine that the thermodynamic efficiency is better than the conversion efficiency of RTGs.

Keep in mind, Centaur was used on Titan which lifted some pretty big payloads. Also, ULA has the final say in that.

This thread could be merged into an Orbital ATK thread: Orbital ATK doesn't launch that much but we've got separate threads for activity regarding ULA, SpaceX, and Blue Origin. As far as thread stealing, it's all the same to me. I was just trying to spread the word to whoever was interested.

It's not necessarily the vehicle that's the problem but the payload that is sometimes not designed to be held at 1g lateral.

Good call. I thought about starting an Orbital ATK thread for the Minotaur C launch last week.

It's the conning tower on the USS Iowa. Basically, it's where the Captain and high ranking officers go during a battle to give orders and not get killed if they get hit with a shell. Usually the conning tower is the most heavily armored part of a combat ship. Edit: that might actually be the USS New Jersey but it's still an Iowa class battleship.

It's not like ships have never been designed with bomb proof rooms.

Conveniently, I fly to Florida on the 28th. How much are tickets for the hype train?

It depends on what you consider to be a prototype. In my world, a prototype could be anything from something that's completely unique with most or all parts being custom/hand fabricated to a fleet (5-100) of vehicles that are more or less identical and have parts that are production representative made from semi-permanent tools.

Just finished poll, go for launch.

For those that are interested in watching.

Kerosene engine: NK-33 all the way. Just in general: I will have to echo @Bill Phil and say the RL-10. It's simple, it has great performance, and it makes a great upper stage engine.

nevermind

Ultimate answers for ultimate questions, excellent. I’ll start: 42. I get your point though, a thread for random science facts or something?

It's largely dependent on the mission though. For example, the fuel margin for a deep space probe is likely double or more than what they need to accomplish the primary mission. However, they usually plan on having an optionally extended mission. Fuel margins for sending resupplies to the ISS or other single use craft with short durations is probably much smaller.

No. Also, you're exchanging potential energy (objects in a gravitational field) for kinetic energy (wheel turning). As the weights go back around the wheel they gain their potential energy back in exchange for kinetic energy slowing the wheel back down. Basically, you've made a pendulum. If you attach a generator to it, you are converting kinetic energy into potential energy (electric this time) and the wheel slows down. Electric power generation works by converting energy from one state to another. There are always losses from thermodynamics or friction or whatever so perpetual motion devices can't exist. There are things that are practically unlimited like using Jupiter for a gravity assist. You trade some of Jupiter's orbital energy to your spacecraft. The spacecraft gets a speed boost but Jupiter's speed barely changes because it's 24 orders of magnitude more massive.

This happens from time to time in automotive. Like, it's cheaper to fill up the corporate jet with tail light assemblies and fly it to Mexico than to have the assembly line stop due to a parts shortage. So yes, literally chartering a jet to get parts on time is cheaper than having an assembly line stoppage.

CFR Part 23/25 are "Code of Federal Regulations" for airworthiness of aircraft i.e. FAA regulations. Part 23 generally covers smaller aircraft up to 12,500 lbs gross takeoff weight (although takeoff weight isn't the only factor to determine which part if falls under) while part 25 covers larger aircraft usually commercial aircraft but there are a lot of business jets that fall into this category. One of the factors that will determine which part an aircraft falls under is pilot information load. Having a high pilot load will put an aircraft into part 25 even if it's small. Conversely, an aircraft could get an exception if it has low pilot load but is still fairly large keeping it covered by part 23. Among other requirements, aircraft subject to part 25 has to have 2 pilots while part 23 only requires 1.

I'm pretty sure the G650 is a Part 25 aircraft as it requires 2 pilots. That being said, very little has happened in the bizjet market (part 23 and part 25) since the 60s. Sure, some new technology has come about and avionics and engines have gotten much better but nobody's really paved any new ground. The fanciest thing to have happen in the bizjet (not even a bizet) market was the Beech Starship which was arguably a huge disaster. After Beech broke the ice with the FAA, a few other companies have had limited success with innovation (Piaggio P180, various composite aircraft from Beech, Cirrus, HondaJet, and others) but the fact remains that the bizjet market is stale and any "new aircraft" are really just derivatives of existing aircraft with very few exceptions. All this to say, @mikegarrison is not wrong about the order of magnitude to develop a new spaceaircraft, I'm merely reinforcing the point that development costs are extremely high in this field. Also reinforced, as evidenced by the lack of innovation, is how risk adverse aerospace is. Why fix it if it ain't broke? The successful manufacturers in the bizjet market are successful most likely because they've taken no risk in the last 40 odd years, everyone else has gone broke.

Even that is generous, 50th percentile male is 78 kg (not that all of the passengers would be male) but from a human factors point of view, 65 kg is low.