YNM

And I sadly can't see much way beyond this and keeping things safe. Li-ion batteries used on aircraft for backup power have enough problems as it is already. The main difference between hydrocarbon fuel and batteries is that while hydrocarbon fuel requires initial activation energy to be provided before they release the internal chemical energy, batteries in general have none of this at all, they need barely anything more than a short to make the reaction go. Would say that it's a slight issue, albeit not really on the car itself and more on the legal/external physical problems like curb weight limit (there's a limit defined to divide cars and larger vehicles, you can't use the same license) as well as in a crash (not really wrt the car but with the thing it hits). We're well on the way through getting past these problems however.

Yep, EDF is popular with hobby aircraft modelling already. If anything, one of the problems with turbojets is because of the very high velocity of the exhaust that they make. When directly blown into otherwise "static" air it makes for less efficient transfer of momentum. Turbofans corrected this by first mixing the higher-velocity air from the core jet with intermediate-velocity air (off the fan on the front) and only after that mixing it with ambient air. When dealing with electric propulsion I think the goal is to simply have very high efficiency over either speed or raw thrust, particularly because of the very high mass per energy stored that's available for electric energy storage for now. Given advances in propeller blade design and the reduced need for very fast travel (most people would appreciate the lavishness of the service instead of being flown in a tiny dart very fast) I think propeller (or at least unducted fan) form factor might be the shape of airplane engines to come. Also I think this was that whole "electric propulsion" thing I've heard a few months ago. Well it is interesting but the sole reason to use this thing is when you absolutely need small cross-section like fighter jets.

That's also an option, very simple one at that. We've been there, done that too (Skylab).

Probably halfway between modified Dragon v2 and v1 actually, since NASA is already enticing them to do Antares-style cargo resupply, the avionics are the same and the only change is on radiation and heatshield I suppose, also larger tanks/more fuel. Probably less cargo as well due to increased LSS duration. Maybe 3 seats rather than 4 and a lot more stuffing. Definitely can't just use a v2 since the dV is going to be tight. While HLS would be the vindication of Starship cargo I think it'll take somewhat longer for it to start launching people. Also if it does end up doing Gateway it'd probably make a shorter life out of Gateway itself - preferably you want a much larger station.

Honestly given that SpX is now involved on Gateway I think it's only a matter of time before commercial crew resupply to Gateway itself starts after the station has been established...

Given we already have resupply mission from JAXA planned for it sometime in 2024 (this document, this page) I think it'll see continuous manning much like ISS currently does. Plus neither Ariane 6 nor H3 can loft anything substantial to LLO anyway... Honestly I think that SLS won't be the one that seen to take the spotlight in the end, it'd mostly be remembered as something that helped put a few stuff up but beyond that it's all commercial/near-commercial. SLS launch cadence now does look very silly but back when we're flying Shuttles 3/4 times a year, expending what's basically an ET and two SRBs to loft payloads was already the routine anyway. The only real pain in the back was RS-25 which had to be cost-reduced because RS-68 won't fit. (SLS is really close to Ares V in all but engines, as well as upper stage where they doubled down from the J-2s.) Anyway this isn't the thread for it, I apologize. Godspeed Bill Nelson.

Only reason why they won't do this is because they'd soil the station and ruin it. They already regularly soil themselves in EVA... "Colony" as in the old days have to be distinguished from an "outpost" I think. ISS and McMurdo station is an "outpost", whereas Falkland Island and Svalbard fell more in the "colony" end (Pitcairn island is a dividing example on the "colony"/"outpost" distinction I suppose). If you want a colony, you have to be able to sustain yourself completely there, more or less. And we aren't even ready for Antarctica, so let alone most of the outer space, be it Mars or the Moon. As for whether we can actually develop the technologies to ? I'm fairly sure we can - the question then fall on what the heck are you actually doing it for. Svalbard had (and to a certain extent has) mining, Falkland Islands had whaling (and animal husbandry but idk whether the produce from that even goes beyond themselves). Tourism has now filled the gap left to an extent. One could argue that tourism might support a space colony, but for the time being what's exactly different between an LEO tourism and a Moon tourism ? You get to be in space is a large enough thing in itself. Maybe after I'm dead we'd see people taking a holiday to the Moon or Mars but within my lifetime I question we'd have proper space "colonies".

Honestly SLS is only to pre-position mission elements IMO. Can't see a lot of Orion flights myself. SLS would mostly be relegated to lift up the heaviest stuff like modules etc. for the station and maybe some surface elements. Looking at the partners for Artemis (and Gateway) itself at least one other government does look up to commercialization of the mission itself beyond the initial efforts so SLS as it arrives today isn't going to be used apart from a few early key things.

SpX is still on the whim of it's owner though pretty much. If he dies or something so will the rest of it... Would say that Gateway is already way too far into the commitment, so anything that can be named as "in support of Gateway" won't be axed either. Honestly I can see a win-win solution between ISS and Gateway - ISS would be relegated to commercial development, Gateway would be the new ISS for the governments.

Would it be from the L-1011 or is it from a B-52 or something ?

Going live, t-15 mins Overlaying graphics on the fairing...

'no specific target fire time' so, wenfire ?

They were doing upper stage cryo test two days ago, and today they were planning to do the first stage cryo test, however they were caught in a rain so it's most likely not going to be done today. EDIT : Video from Asahi Shimbun of the rollout : Test was completed on March 18 ~01:00 JST (UTC +9), but a second test is planned; however the second test cannot be carried out and so far the rocket has been rolled back into the VAB.

Well, OP says that he don't want to deal with the maneuver nodes at all, so probably let alone doing it 3 times. Although I do get the impression that part of the problem is just how imprecise the handles could be, and I've addressed this in my post here as well. Being able to change the values of the dV vector by the numbers is handy regardless of if you're doing it the lazy way or not.

Because they had a 3rd pilot onboard (crew movement) and they were lucky that a) he heard something about the MCAS system and b) the system didn't choose them to die that day (Ethiopia pilots turned the system off but it still worked on it's own). The reverse problem happens on AirAsia QZ8501 where the pilot decided that the plane was too stupid to warn him and reset the flight computer in-air. Also the SSJ-100 crash where they decided the GPWS was faulty because the mountains they were flying around doesn't exist. As for the problem at hand : 1. We have automation done succesfully and routinely safely already - the only problem is that they either operate on a strictly one-dimension basis (elevators and trains) or on three-dimension but where the margins are larger (airplanes). 2. The problem is in data and training, and the fact that these will invariably take a long time due to the human nature of other drivers and users on the road (invariably controlled by a human - pedestrians are just humans on feet - or even worse an animal, like a pack of livestock). 3. Automation on cars isn't new, we all have started on cruise control decades ago, and lane following have started to become standard on these as well. Key point however is that the driver is still expected to be ready for anything on the road itself.

These already exist from MechJeb but the resulting nodes are a bit of a hit and miss, esp. when selecting the most efficient spot on the plot.

Stay safe when driving ! I'd say that one or two falls are a common part of everyone's history with driving motorcycles. I fell down twice - once on loose sand, once on an oil spill (that had covered the whole road). You never know the limits of your motorcycle and your driving until it comes, and I'd say that having such events make you recognize what has to be done better in such situations. Although if your body starts to ache I suggest looking up a physician. It means that it was probably bad enough that your body have a trauma afterwards. I didn't after mine, but on an unrelated injury that happened to me, when the feeling wore off and the proper pain comes I slept straight to the next day. ______________ Ten years ago today, a Mw9.1 earthquake struck the north-east coast of Japan, triggering a large tsunami that damaged many buildings, as well as the second worst nuclear accident after Chernobyl. Aftershocks of the earthquake are still felt today, the most recent large one happening only a month ago.

You'd be surprised that the guy who came up with the standard agrees with the less popular opinion.

They make good products, even if it's not the top of the line. Are the limitations with the CPU/GPU or what ? I think laptops from that time still features replaceable-socketed CPU, although if it's a GPU problem you're most likely toast.

That'd be interesting if they actually approved it. Well I hope they can go and see if they really need the place to remain supported or not. There's still the other telescope at Arecibo for now.

It is a second possibility as well, the vernier/landing engines are not necessarily the same as Rutherford engines. But yeah honestly the most surprising consequence coming out from this announcement is just the engine, esp. with the perceived deadline of merely 4 years, an impressively short time for a rocket engine development if they start from scratch. Plus that'll mean they would have at least two engine production lines out, if the verniers and upper stage ends up being not Rutherford that goes up to three lines. Yeah, not saying that electric pumps can do everything. Just realized that Merlin used to make about 690 kN, although now it's rated up to 980 kN of thrust. 550 kN engine is a pretty big engine to run with electrics I suppose, unless RocketLab have a lot of confidence. Found this paper for electric pump engine performances which aligns with what Rutherford is doing. Uprating it to 550 kN - or even 250 kN - would be quite a challenge.

Well, they need to start thinking about that... Pretty sure Shuttle's insulation pads weren't designed with re-entry in mind really, but rather for keeping the craft warm or something. Apollo needs the roll program because of the stainless I suppose... Orion capsule is covered with Nomex on the non-heatshield side.

What, they don't need to roll the tanks ? Or is it going to be stainless side to the Sun, heat shield side away all through interplanetary transit ? Honestly I don't think the tiles are that heavy, even if it is they can just run all the pipes etc. on the other side. Also at the very least you need insulation up in the crew compartment, although this would cover all sides equally.

I've always assumed that it'd be a little like 'ye olde' Shuttle with thermal insulation on the other, non-heatshield side...