I'm both happy for you and sad. Its exciting, but 50 years ago people expected this to become a normal thing. The excitement and the rarity shows how badly we neglected space since then.
The big and annoying issue with the Crew Dragon design seems to be the chosen RCS fuel (AFAIK, monomethylhydrazine and N2O4), which makes both fueling and clearing after landing a delicate process.
Hopefully Crew Dragon proves itself as a capable platform for Earth-orbit transportation, but this fuel issue is a hard one to counter.
Hypergolic fuels have TONS of advantages, including extremely reliable ignition. Basically all crewed orbital spacecraft have used hypergols in some ways. SpaceX's Starship will not use hypergols, although it probably won't be available for years.
> Basically all crewed orbital spacecraft have used hypergols in some ways.
Right, but Soyuz spacecraft is flying since 1960-s, has a half a year orbital storage time, and yet it has no toxic RCS for the capsule. At least that simplifies handling after landing.
And it was long since proven RCS doesn't need to use toxic components. The fact that Crew Dragon still uses them points more to the tradition than to the necessity.
Soyuz still uses hypergols on the service module. SpaceX has no separate service module (just the trunk which has no propulsion), which saves money as the whole propulsion system can therefore be reused. If the Soyuz used peroxide for the service module, it’d weigh far more due to lower performance.
Peroxide has serious limitations in performance (and, like all strong oxidizers and monopropellants, has serious safety concerns by itself and can burn you). SpaceX does nothing out of pure tradition, if that hasn’t been made clear by their approach so far. The future is not hypergols, but there are legitimate reasons for it today.
Kliper is a relatively modern design, which, while admittedly not produced in metal, used much more benign components for RCS. And Kliper also doesn't have a separate service module.
One can always say "but Klipper is a paper spacecraft". Of course, nothing is perfect. Buran can be brought as an example, and arguments against that could be broght up - "oh, it's too old". The point still stands - it's possible to not use toxic components, it's desirable - and it's not done. In my opinion, performance arguments - for a relatively low delta-V system - aren't convincing. After all, Crew Dragon is much bigger and newer craft that Soyuz.
Paper spacecraft can do anything. Buran was designed for the same mission lengths as the Shuttle, on the order of a few weeks at most, not half a year or more. For long mission durations, storable hypergolics are the way to go for now. We don't have good flight time on anything else, and we need that for something we're putting crew on.
> For long mission durations, storable hypergolics are the way to go for now.
Soyuz is a counterexample which flies for decades. Lockheed's engineers working on orbital fuel storage (Advanced Cryogenic Evolved Stage) will also point that it's not a law of physics.
SpaceX - correctly - speeds up the process by maximally reusing the known solutions for the problems - this not only makes development faster, but saves a whole lot of money on testing the variants which will be found not working.
I disagree that SpaceX does nothing out of pure tradition. In many areas, where invention is hard, unlikely and expensive, SpaceX instead opts to optimize the known solutions rather than invent new ones. Practically everywhere - landing first stages, full-flow combustion Raptor, reusing Dragon, all of that has good precedents in Delta-Cliper, RD-270, Gemini and VA TKS - SpaceX makes a right commercial decision to use proven technologies, which brings us results and doesn't break the bank. Note that truly innovative things, like spinning detonation wave engines, are still in the research labs, and not - at least in a big way - in the SpaceX factories. That's correct way to go considering that we have and know a lot already which we don't use fully.
> if that hasn’t been made clear by their approach so far.
No it hasn't. They just need to be read differently. The fact that they brought - well-tested and beneficial - traditions from computer industry into rocketry doesn't make them doing everything strictly from the first principles.
Why weird? Choosing something takes trade-offs - in the case of SpaceX capsules, they chose not to develop non-toxic technoogy, saving some time and money, but making an inferior product. It's not weird, it's their decision - which I'm not sure is good.
Given that we hopefully will soon see Starship flying, that may be rather moot point though.
Your posts use terms like "inferior" to automatically shift the conversation to the notion that hypergolics are inferior solely because they are dangerous chemicals, and ignore engineering decisions that are made.
Its the same as arguing that RP1 engines are inferior to H2 engines because RP1 is based off fossil fuels. It's not relevant to the point.
RCS engines are practically always hypergolic since you need to be able to pulse on and off very easily/quickly, and propellents need to be storable (non-cryo). If you look at the choices remaining, they're all various levels of extremely toxic.
Buran had non-toxic components for RCS. Kliper was planned with non-toxic RCS. Soyuz spacecraft at least has non-toxic components for capsule RCS, so when the capsule lands, it doesn't need to be approached in a chemical protection suit.
It's not a question of choices - there are choices. I suspect it's a question which is considered less important so far, so SpaceX didn't pay that much attention to it, considering they had to do a lot of other things already. But I hope we'll get there sooner rather than later.
> I suspect it's a question which is considered less important so far, so SpaceX didn't pay that much attention to it, considering they had to do a lot of other things already.
They had a lot of other things to work on, so they - because of that, I suspect - didn't pay that much attention to it.
I strongly suspect they've given the matter orders of magnitude more engineer-hours of consideration than you have. Yes, they have many other things to consider as well; that's why they have a lot of engineers.
I think for some questions you don't need to measure who spent more time to determine who's more correct. I also think that SpaceX realized they'd need to give many more efforts to develop this particular superior technology - I agree that this could be expensive and would take time. Maybe the Starship plans also affected their decision.
Buran was using LOX, storing it for up to two weeks with a cryocooler and a complicated cooling system, Crew Dragon can be rated for hundreds of days and doesn't have the volume/mass/cost to spare.
Dreamchaser with its propane/N2O thruster is a better counterexample. They avoided toxic components so it could theoretically land at any airport, making it a strong selling point. There are also new(-ish) hydroxylammonium nitrate based propellants which are storable, better than hydrazine and aren't toxic either.
> Crew Dragon can be rated for hundreds of days and doesn't have the volume/mass/cost to spare.
Mass is often an issue with spaceflight. We're arguing about what's better overall, not what's better by all possible criteria. Crew Dragon I'd say has more mass to spare than earlier spacecrafts - because at least of economy of scale and more mass-efficient subsystems.
Propane/N2O is an interesting combination. It needs to be pressurized quite a lot (the N2O in particular) to stay liquid, ruling it out for large systems like launchers. But for small thrusters, it means the system is self pressurizing, meaning (potentially) less mass and complexity for the entire thing.
HAN and ADN are also interesting options.
That being said, they should be tested and flown a lot more on cargo launches before they're ready to be put on crafts carrying humans.
Soyuz still uses UDMH and nitrogen tetroxide as its propellants. It simply jettisons the propulsion module before reentry so the reentry module has no thruster system and therefore no (toxic) fuel.
With the return of a SpaceX vehicle, the recovery crew don't have suits on, that would be very unwieldy at sea, and they would just back off if trace gas detectors measure a toxic leak.
> Soyuz still uses UDMH and nitrogen tetroxide as its propellants.
Right, but at least Soyuz doesn't have them in the returning capsule. Crew Dragon could be just as good in this aspect, but unfortunately isn't. So when moving the capsule from the sea the team has extra dangers.
Isn't the crew dragon using those hypergolic thrusters only in an abort scenario? IIRC they did test using them to do a propulsive landing, but the current plan is to use parachutes and land in the sea, no? And those thrusters had some ports to prevent seawater ingress, so I would guess that if they haven't been fired and there's no leak there's no danger.
From a quick search their main RCS is still a dimethylhydrazine which is quite toxic. They're just on the engine part of the craft instead of on the capsule so it doesn't come down to Earth.
Right, but at least the capsule, which goes through atmosphere and keeps people inside, doesn't have the toxic substance.
It's not saying Soyuz is perfect, or near that. It's about Crew Dragon - the spacecraft could use already existing ways to avoid toxic materials in operations, and it wasn't done. And it's hard to do after the design is complete. So we can reasonably hope for the next spacecraft to be better - fortunately trying to make Starship refuelable on Mars and limiting propellants to LOX and methane works for the goal of reducing toxicity.
The way to do that requires throwing away the entire engine section which it a lot of equipment when you're trying to make a commercially viable option and need to reuse as much as possible.
One might say that Crew Dragon's days are counted already.
Even SpaceX' Gwynne Shotwell (she is SpaceX' long-time COO, in case you do not know her yet) is hoping that SpaceX will fly people on Starship in maybe 3-4 years and she is way more grounded than Mr. Musk.
They plan to achieve this unreasonable sounding feat by producing large numbers of Starships and launching them very often to accumulate massive experience with the craft in very short time in parallel basically.
I wouldn’t say she is that much more grounded: she has also said they are planning on passenger New York<->Shanghai rocket trips for a price between an economy and business class plane ticket by 2028:
So that's longer than from Alan Shepard's flight to Moon landing. And the task - with all peculiarities - still seems simpler.
I don't think this points to the "ungroundness" of Shotwell. Similar projects were discussed and BOTEd for quite some time. The whole suborbital tourism thing is practically rather similar technology, and we're a couple of decades in the implementation time for that.
It is hard to emphasize how much harder that last X% of reliability is to allow something like this for flights of hundreds of civilians. We’re not talking space tourism but a utilitarian service for business travelers and stuff.
Hey don’t even have a settled design and have made radical design changes recently.
SpaceX commercial crew program began in 2010 and is only just coming to fruition.
But principles are long since known, and prototypes are coming more and more often. Delta-Cliper, Space Ship One, New Shepard, unmanned Dragons, first stages of F-9, aerodynamic tests in wind tunnels - all of them contribute, to various degrees, to the technologies needed.
That doesn't seem like a crazy estimate. It's not conservative, but seems doable.
The very first SpaceX launch was in 2008. Since then they have developed and iterated on reliable, reusable space travel. Its plausible that they can adopt that technology to a commercial platform in 8 years.
What's great though is that all the technology, systems, tooling, procedures, experience, etc.. that has been developed for Dragon 2 will roll right into Starship. It's a huge head start.
Earlier this week when they were de-fueling they mentioned that the "escape system" was still active during that process. Is that because the fuel is potentially dangerous? Tangentially related, can the "escape system" be activated even when the rocket itself hasn't left the ground? I watched the escape system test but IIRC it involved launching and then aborting so the pod that carries the crew was already high off the ground before the escape system was triggered. It surprised me that it could triggered from a standstill.
Anything involving fuel is dangerous. Demo-2 is first time that humans are on the rocket while its being fueled. The escape system is on while fueling and defueling since those are high risk times for the rocket.
Even when boarding commercial flights, crew tells you not to fasten seat belts if they’re still refueling. Just in case you need to evacuate (of course it’s just a token concern, I would t expect to survive an airplane bursting in flames even if still docked.)
people have survived even crazier situations, like an airplane cartwheeling down a runway AND THEN bursting into flames. (100+ survivors, out of ~300 IIRC)
The abort system is like ejection seats: the greater the part of the flight envelope it works in, the better, because you have smaller portions of the flight that problems are unsurvivable. The abort system tests were for the most difficult regimes of flight: maximum dynamic pressure, and zero altitude, zero airspeed. Having tested that, they can be sure it'll work in less difficult sections.
Maybe not, but they'd better do. The experience can be changed - SpaceX, for example, convinced them that loading fuel is better done with crew onboard.
The point is, it's better not to have toxic components close to humans, and it also can be done technically. There could be reasons otherwise, but so far I don't see them particularly convincing, robustness and all notwithstanding.
You're not arguing anything. You're saying "I think something else can be good too".
Until you literally give an actual engineering (comparison of performance/reliablity/etc) reason that hypergolics are the wrong choice to make, this is effectively saying that "something should be different because I think so"
> Until you literally give an actual engineering (comparison of performance/reliablity/etc) reason that hypergolics are the wrong choice to make, this is effectively saying that "something should be different because I think so"
As with many discussions, we talk here mostly qualitative differences. Quantitative differences are harder to get by - for example, back of the envelop calculation says that 30 kg of peroxide in Soyuz landing capsule could be, roughly, replaced with 15 kg of hydrazine, so you'd have a 15 kg mass saving here, but in general actual engineering calculations are harder. I wish they wouldn't be such.
Given those very crude estimations and the practice, which shows there are no big unforeseen problems, we have a valid arguments for the alternative. It's an engineering argument, an estimation and not necessarily full calculations, and it's not effectively an arbitrary opinion. You may finally decide the issue using hard numbers, but since we don't have them now, the question stands.
What would be the options? Compressed cold-gas (which don't have much kick, and require compressed gas which carry their own dangers).
You could go with a monoprop Hydrazine which would eliminate half the toxic stuff. There are also some new developments here: hydroxylammonium nitrate (HAN)/water/fuel ? No idea of the trade offs there.
Biprop hydrocarbon/gaseous compressed oxygen? Presumably that'd require an ignition source (and power source). How do you see that trade off?
Do you consider high-test peroxide non-toxic? (It certainly has a different risk profile, but is nasty stuff on contact with about anything that can oxidize). The decomposition would also make storage and rotation a consideration.
Soyuz uses straight hydrogen peroxide, I believe, 82% concentration. For 3 tons capsule it takes 30 kg of peroxide - monopropellant - to land.
Buran is still the example of a high tech option - it used LOX and kerosene for RCS, the biggest trick was to keep LOX liquid for a month-long missions. It was done with mid-1980 technologies.
Kliper planned to use LOX and ethanol. The craft wasn't completed in metal though.
One has to remember that hydrogen peroxide - the rocket concentrations are called HTP, high test peroxide - can be used as an oxidizer, after a catalytic decomposition - and after decomposition HTP is easily hypergolic with fuels. "Hypergolic" doesn't mean "nitrogen-containing, long-storing and toxic", it means "self-igniting" - and it could be non-toxic (or at least HTP toxicity is on the whole different level that hydrazine's one).
To come back from orbit you don't need too much delta-V. So Soyuz uses 30 kg of peroxide, maybe it would use 15 kg of hydrazine for the same effect - you're saving 15 kg in a 3 ton spacecraft but losing on toxicity. Similarly, Crew Dragon is a heavier craft, flying on a bigger F-9 rocket, it can probably allow for some extra mass spent for RCS fuel in order to make it non-toxic.
> You could go with a monoprop Hydrazine which would eliminate half the toxic stuff.
Hydrazine is, I think, a way bigger half. NTO is comparatively benign... not so carcinogenic. But still lethally dangerous :( .
> Biprop hydrocarbon/gaseous compressed oxygen?
Was done at least. Yes, it would require extra systems. You think it can't be done?
> Do you consider high-test peroxide non-toxic?
Comparing to hydrazine - yes.
> The decomposition would also make storage and rotation a consideration.
Yes. Have to chill it, take care while in storage and keep tanks extra clean. But still.
Crew Dragon carries 3 klbs, or 1.4 tons of hypergols. It doesn't just use those tanks for RCS, but also for the abort system. Also, Crew Dragon is closer to 14 tons at landing.
Indeed. If you want to switch to a less efficient propellant, you also have to explain how to make the launch escape system work with it, otherwise you've traded the extra safety of not having to handle hypergols for a massive extra risk in a less capable escape system.
HTP may be (comparatively) non-toxic but that doesn't mean it's necessarily less dangerous. The Kursk (Soviet ballistic missile submarine) was sunk by a malfunctioning HTP torpedo.
Having an oxidizer that easily starts to exothermically decompose sounds extremely dangerous. This was pointed out as the main factor why HTP "lost" to NTO/IRFNA as the storable oxidizer of choice already back in Clarks Ignition (1972).
The toxicity of NTO is bad, extremely so, and everyone knows it. But having your oxidizer tank suddenly go boom on its own accord is even worse.
The suits are just pressure suits, more for basic protection and temporary loss of pressure, not extended EVAs or anything. They do look pretty comfortable, though, and I think the audio and signal are better.
The touchscreen interface is "different" - the astronauts talked a bit about helping SpaceX design it and the pros and cons of it in a recent interview. I wrote it up here but you can also check the original long NASA TV thing.
I watched the "Everyday Astronaut" Youtube stream where he said that those are IVA suits (as opposed to EVA) and can only hold pressure for a couple of minutes, enough time for the capsule to return safely to earth in case of an emergency.
> Lifting off from Launch Pad 39A atop a specially instrumented Falcon 9 rocket, Crew Dragon will accelerate its two passengers to approximately 17,000 mph and put it on an intercept course with the International Space Station. Once in orbit, the crew and SpaceX mission control will verify the spacecraft is performing as intended by testing the environmental control system, the displays and control system and the maneuvering thrusters, among other things. In about 24 hours, Crew Dragon will be in position to rendezvous and dock with the space station.
It's absolutely incredible to see this. So much work to get us here. So much work just to organize this launch event. Seeing astronauts getting dropped off in one of the most technologically advanced automobiles on Earth and walk into the capsule sitting on top of a rocket which is the Pinnacle of humanity's biggest advancements in technology and space is astounding and goosebumps-enducing. What a time to be alive!
Because it's the first time in a decade the US has done it, and done it in a way that is significantly less expensive, paving the way for much easier access. It's a minor historical event in terms of human achievement since, as you said, we've done it before. But it's a major economical event in the history of space exploration, and historic for the potential that represents.
The big deal is what is now much more likely to happen in 10 years because of what just happened. People are inspired by a successful mission and that makes the possibility of future missions more real.
This is a big deal because a group making up a medium-sized private company with a private company budget was able to accomplish what a nation-state sized government with an unlimited budget was able to accomplish ~40 years ago. And if they can do it, then it won't be long before other companies do it too, which means that space travel will no longer be limited by political ambitions or realities.
This is the Apple II moment of space travel: when megacorporation giants were squeezed out of the market in a few short years by some dudes working out of their garages.
I was thinking it seems a bit unfair to go on about how amazing it is while ignoring the Russian rockets that have been doing the same mission for years eg. https://youtu.be/erfXf08tuFg?t=3906
However watching that it's cool to see cutting edge tech rather than the 1960s style stuff. Also hopefully this is just a step for SpaceX on the way to Mars and beyond.
Imagine your same argument but comparing old computer modems to new ones. I dont get it why is a gigabit connection a big deal? I have my 14.4kps modem and I can download images just as good? ... Now we can do a lot more, for a lot cheaper, and the cheaper it becomes the more we can do in space. We could do mining, better satellites, colonies, better research.. Space is the limit ;)
It's a couple ex-military pilots being driven through one of the more secure sites in the United States. Is this Warhammer 40K aesthetic not out of place?
It replaces NASA's M113 armored personnel carrier, a tracked vehicle which dates back to the Vietnam War. The fire crew sits in there for protection from an exploding rocket. The vehicle is great for evacuating astronauts.
If you want the closest view of a launch without being in the rocket, get some firefighting experience (preferably on an aircraft carrier or something of similar hazard) and then ask your senator to recommend you as a qualified guest firefighter.
And 116 years ago an engine could only fly us from the top of a hill to the bottom. Don’t underestimate how quickly technology can change what’s possible :)
Musk plans to send a SpaceX rocket to Mars, with cargo only, by 2022, according to the SpaceX website. A second mission, which would take more cargo and crew, is targeted for 2024
I would expect Elon to push really hard to send something to Mars in 2022 aboard Starship, even if it's just an empty ship. They need to try navigating with precision and landing. It's a 2 year delay if they miss that window.
well, if adapted for Mars conditions that dropped Cybetruck would be very useful for the landed crew of the next mission. The Mars trucks are going to be electric, not ICE :)
I'd imagine they'd probably send a modified cybertruck with some non-perishable supplies of some kind in the hope that there'll be some useful supplies on the planet for future missions even if stuff doesn't go smoothly.
Could be good marketing, ‘Cybertruck - tough enough for Mars’ vs ‘Built Ford Tough’, or just make a Super Bowl commercial with the footage of it landing on Mars.
Ha, not sure if people get how great that choice is if they don't know the beer. For those who don't, Gulden Draak is a Belgian beer which translated would be "Golden Dragon"
They are going to have some time to use the manual controls beforehand, for testing purposes, but I believe the docking procedure itself will be done by autopilot.
They said in the press conference after launch that docking will be automatic. The purpose of this mission is to demo dragon and testing automatic docking is part of that.
There are two rows of physical buttons below the touch screens along with a large manual abort lever. The physical buttons are used for manual docking.
With all due respect to all the engineers that work at SpaceX, the UI of the cockpit has regressed to the point of pure marketing. Same with the suit design, looks like an awful low budget sci-fi film. Functionalism and the beauty in the way things are without adornment is dying. And, it is painful to watch as a engineer who designs HMI systems. IMO design and aesthetic that emerge out of the way things are is so much more authentic than CEO's inspiration from a sci-fi movie genre that was probably conceived by some guy in 80's in half a dozen hours before before putting up a hollywood set. These movie makers did not study UX/UI and it was all about entertaining the audience.
Just look at how functional and beautiful the aesthetics of space flight was like during the golden era of Apollo 11. There was no design. There was just pure emergence of aesthetics from whatever they were doing to make things functional (ok, with some small exceptions like the logo and US flag on the suits): https://www.youtube.com/watch?v=tpLrp0SW8yg
If SpaceX designed a mars rover, it would have gaudy shrouds and plastic covers, probably some LED lights to make it look cool, sleek 30, 45, 60 degree angles everywhere (ohhh space aesthetics), and all kinds of marketing bullshit whereas NASA engineers are focused on what is important. And it is gorgeous without even trying.
> Same with the suit design, looks like an awful low budget sci-fi film.
Or a high budget sci fi film, or a medium budget sci fi film, since literally every film involving a spacesuit ever made had a more reasonable design than the utterly ridiculous, cumbersome, and bulky Hamilton Standard design American astronauts were stuck with for such a long time.
Wasn't the Hamilton Standard suit for EVAs? I don't think the ones they wore today are comparable, they're more of a replacement for the "pumpkin suits"
I thought they were both designed by Hamilton Standard. If not, my bad. I don't think I'd want to stick up for any of the older suits as being aesthetically, or much more importantly, functionally, being as good as they should have been.
Of all the possible critiques of SpaceX, an attack on the new space suits is a genuinely weird one.
I don't know it might just be that it's different from any other suit but it looks like they got stuck between wanting a more modern clean design and the fact that it's real middle aged men that need to wear and move in them and they just look weirdly boxy with the big white expanse on the front and back of the torsos. Look at these for example they're just very square and empty.
It's mostly just that older suits [0] and scifi suits [1] have painted a picture of there being more stuff involved in a suit to break up the expanse of the torso and the back, so they look weirdly plain. I bet they're perfectly fine functionally, and the single port seems like a good idea, but the do kind of miss the mark for me aesthetically.
Also really hope they figure out how to make flexible necks work because this [2] video of them trying to look to the top of their rocket looks so uncomfortable.
I agree fairly strongly with your sentiments. I wanted to know more about what the pilots think of it.
In an article[1] a month ago, Bob said "I don’t think I’m going too far out on a limb to say that the right answer for all flying is not to switch to a touchscreen, necessarily. But for the task that we have and to keep ourselves safe flying close to the ISS, the touchscreen is gonna provide us that capability just fine."
Doug explained "The difference is you’ve got to be very deliberate when you’re putting in input, relative to what you would do with a stick. Because you know, when you’re flying an airplane for example, if I push the stick forward it’s going to go down. I actually have to make a concerted effort to do that with the touchscreen, if that makes sense."
So it sounds like there's more cognitive overhead to use the touch interface for flying. I did think the touchscreen was perfect for the procedure checklists shown extensively in the middle console during today's flight.
In the on-board media event a few minutes ago, he pointed out "One thing that does get lost is there is an extensive button panel down below."
I'd be concerned about touch screens where the user input is at the mercy of Chromium and then the OS, which itself is complicated enough. Maybe they have some crazy Chromium + RTOS solution though. I'd be interested if they set up mechanical testing for the touch screens and what their error rate for handling a touch is.
A stick while flying is useful for weather, but there's no weather in space. In space, a stick probably provides little feedback.
This is some seriously lame backseat HN driving. Zero skin in the game, sat in on zero mission briefs and zero design decisions. Never used it. Never spoken to someone who has.
Yet think it makes for a good HN post to "facepalm" at their decisions.
You should listen to the astronauts. SpaceX is developing all of it with them and for them. They seem quite happy with UI because it allows rapid iteration on procedures. If they screw up something SpaceX can adjust interface within days. With space shuttle they would need to wait months and months.
I mean, it's possible, but I'm skeptical of any argument here that assumes the astronauts would be willing to risk their lives using systems interfaces they believed would cost them precious time in a life & death situation. At least without more direct evidence than speculation that can't be disproved for upwards of a few decades.
Astronauts at NASA are specially taught in PR. They have to protect their partners. You absolutely can't fight astronaut or military pilot being frank of things they don't like.
I get the Apollo esthetic (I watched the Skylab missions as a kid on our black & white console TV). But two of the major differences between then and now is cheap computing and additive machining. Cheap computing means you don't need a zillion physical switches for everything. So the cabin is less cluttered and the usability is better.[0]
The advent of additive machining means everything doesn't have to be right angles and hard corners.[1] As a result the cabin will be safer because your astronauts are less likely to be hurt if there is an unanticipated thrust. Parts can also be made to fit better and to closer tolerances.
With regard to the suits - they look far better than the orange shuttle flight suits. I think that having the umbilical on the thigh was a good innovation. No idea how comfortable they are, but they're only going to be worn for launch & entry. I expect Doug & Bob have already put their shorts & t-shirts on.
[1] Which is the same reason why shift levers in cars are being replaced by knobs and switches - so the passengers don't get hurt by them in an accident.
> The physical buttons are used for manual docking.
I don't think so, they're using the screens for docking too according to their own site. [0] You can do the same basic task the pilot would be doing during a manual approach from what I think is Waypoint 1 (meaning Dragon is in front of the ISS pointed mostly towards it). You can see the actual text on the buttons here [1] and they're all critical system tasks like power cycling the controllers, aborts/emergency response commands, or manual triggers for things during landing.
Personally I found the lack of analog input control harrying toward the end. A toggle between "large" and "normal" thrust mode is all you get. Normal felt like it wasn't fine-grained enough.
BS. Do you think for a second some Tesla engineer or Elon Musk himself could design the most important control panel on a spaceship to look pretty without the support of the people who have to use it? If the astronauts or NASA engineers weren’t ok with it, it wouldn’t be there.
Reading between the lines, I have a hunch the astronauts have mixed feelings about it ("this is certainly different") but ultimately accept it as adequate for the job. You are correct there were a lot of iterations involving the engineers and the pilots to arrive at the final result.
"Crew Dragon" has been added to the Star Walk 2 app on iOS. Just had a pass over the UK (not visible). This gives an AR view of the sky. It's on the same trajectory as ISS, some number of minutes behind it.
That's quite normal. It happens on pretty much every launch to some extent. Something to do with vibrations causes by the landing burn and directional dishes
Depends on the mission, for something like this it deorbits fairly quickly due to the drag of the low orbit. To geostationary transfer orbit it takes longer but the periapsis (lowest point) is low enough to slowly deorbit it.
Then we have launches straight to geostationary orbits and similar, for those the second-stages will essentially never come down and they end up positioned in a graveyard orbit.
SpaceX was talking about trying to recover the 2nd stage back in 2018, Elon suggested they would use a giant "party balloon" and land it on a "giant bounce house." I haven't heard any talk of progress made since then.
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[ 5234 ms ] story [ 3046 ms ] threadTake off eh?
https://www.imdb.com/title/tt0086373/
Hopefully Crew Dragon proves itself as a capable platform for Earth-orbit transportation, but this fuel issue is a hard one to counter.
Right, but Soyuz spacecraft is flying since 1960-s, has a half a year orbital storage time, and yet it has no toxic RCS for the capsule. At least that simplifies handling after landing.
And it was long since proven RCS doesn't need to use toxic components. The fact that Crew Dragon still uses them points more to the tradition than to the necessity.
Peroxide has serious limitations in performance (and, like all strong oxidizers and monopropellants, has serious safety concerns by itself and can burn you). SpaceX does nothing out of pure tradition, if that hasn’t been made clear by their approach so far. The future is not hypergols, but there are legitimate reasons for it today.
One can always say "but Klipper is a paper spacecraft". Of course, nothing is perfect. Buran can be brought as an example, and arguments against that could be broght up - "oh, it's too old". The point still stands - it's possible to not use toxic components, it's desirable - and it's not done. In my opinion, performance arguments - for a relatively low delta-V system - aren't convincing. After all, Crew Dragon is much bigger and newer craft that Soyuz.
Soyuz is a counterexample which flies for decades. Lockheed's engineers working on orbital fuel storage (Advanced Cryogenic Evolved Stage) will also point that it's not a law of physics.
This deserves a separate reply.
SpaceX - correctly - speeds up the process by maximally reusing the known solutions for the problems - this not only makes development faster, but saves a whole lot of money on testing the variants which will be found not working.
I disagree that SpaceX does nothing out of pure tradition. In many areas, where invention is hard, unlikely and expensive, SpaceX instead opts to optimize the known solutions rather than invent new ones. Practically everywhere - landing first stages, full-flow combustion Raptor, reusing Dragon, all of that has good precedents in Delta-Cliper, RD-270, Gemini and VA TKS - SpaceX makes a right commercial decision to use proven technologies, which brings us results and doesn't break the bank. Note that truly innovative things, like spinning detonation wave engines, are still in the research labs, and not - at least in a big way - in the SpaceX factories. That's correct way to go considering that we have and know a lot already which we don't use fully.
> if that hasn’t been made clear by their approach so far.
No it hasn't. They just need to be read differently. The fact that they brought - well-tested and beneficial - traditions from computer industry into rocketry doesn't make them doing everything strictly from the first principles.
Fuels are extensively well studied and hundreds of thousands of man-hours are spent validating these choices
Given that we hopefully will soon see Starship flying, that may be rather moot point though.
Its the same as arguing that RP1 engines are inferior to H2 engines because RP1 is based off fossil fuels. It's not relevant to the point.
Good to know thanks.
It's not a question of choices - there are choices. I suspect it's a question which is considered less important so far, so SpaceX didn't pay that much attention to it, considering they had to do a lot of other things already. But I hope we'll get there sooner rather than later.
> so SpaceX didn't pay that much attention to it
That's quite an assumption. They didn't decide as you would have, so they must not have thought about it much?
> I suspect it's a question which is considered less important so far, so SpaceX didn't pay that much attention to it, considering they had to do a lot of other things already.
They had a lot of other things to work on, so they - because of that, I suspect - didn't pay that much attention to it.
I don't think it's the same as what you wrote.
Dreamchaser with its propane/N2O thruster is a better counterexample. They avoided toxic components so it could theoretically land at any airport, making it a strong selling point. There are also new(-ish) hydroxylammonium nitrate based propellants which are storable, better than hydrazine and aren't toxic either.
Mass is often an issue with spaceflight. We're arguing about what's better overall, not what's better by all possible criteria. Crew Dragon I'd say has more mass to spare than earlier spacecrafts - because at least of economy of scale and more mass-efficient subsystems.
They had insulation and active stirring system, that was enough for 15-20 days. To fly up to 30 days they needed a microcryocooler.
http://buran.ru/htm/odu.htm
> Crew Dragon can be rated for hundreds of days
Isn't Soyuz rated for 200+ days?
> Dreamchaser with its propane/N2O thruster is a better counterexample.
Agree, a good example.
HAN and ADN are also interesting options.
That being said, they should be tested and flown a lot more on cargo launches before they're ready to be put on crafts carrying humans.
Right, but at least Soyuz doesn't have them in the returning capsule. Crew Dragon could be just as good in this aspect, but unfortunately isn't. So when moving the capsule from the sea the team has extra dangers.
https://en.wikipedia.org/wiki/KTDU-80#Pneumatic_Pressurizati...
http://www.russianspaceweb.com/soyuz-ms-kdu.html
It's not saying Soyuz is perfect, or near that. It's about Crew Dragon - the spacecraft could use already existing ways to avoid toxic materials in operations, and it wasn't done. And it's hard to do after the design is complete. So we can reasonably hope for the next spacecraft to be better - fortunately trying to make Starship refuelable on Mars and limiting propellants to LOX and methane works for the goal of reducing toxicity.
Even SpaceX' Gwynne Shotwell (she is SpaceX' long-time COO, in case you do not know her yet) is hoping that SpaceX will fly people on Starship in maybe 3-4 years and she is way more grounded than Mr. Musk. They plan to achieve this unreasonable sounding feat by producing large numbers of Starships and launching them very often to accumulate massive experience with the craft in very short time in parallel basically.
https://www.vox.com/2018/4/11/17227036/flight-spacex-gwynne-...
Not a prototype or demonstration, a real commercial flight service.
I don't think this points to the "ungroundness" of Shotwell. Similar projects were discussed and BOTEd for quite some time. The whole suborbital tourism thing is practically rather similar technology, and we're a couple of decades in the implementation time for that.
Hey don’t even have a settled design and have made radical design changes recently.
SpaceX commercial crew program began in 2010 and is only just coming to fruition.
The very first SpaceX launch was in 2008. Since then they have developed and iterated on reliable, reusable space travel. Its plausible that they can adopt that technology to a commercial platform in 8 years.
The robustness of the system is hard to give up. And fueling and recovery has always been a large production requiring attention to detail.
Has NASA or DARPA put out any requests for a next-gen RCS fuel replacement?
Maybe not, but they'd better do. The experience can be changed - SpaceX, for example, convinced them that loading fuel is better done with crew onboard.
The point is, it's better not to have toxic components close to humans, and it also can be done technically. There could be reasons otherwise, but so far I don't see them particularly convincing, robustness and all notwithstanding.
"I don't think its a good reason to use a thing if we ignore the reasons to use the thing"
I also think general history of technology - including space technology - supports this point of view.
Until you literally give an actual engineering (comparison of performance/reliablity/etc) reason that hypergolics are the wrong choice to make, this is effectively saying that "something should be different because I think so"
As with many discussions, we talk here mostly qualitative differences. Quantitative differences are harder to get by - for example, back of the envelop calculation says that 30 kg of peroxide in Soyuz landing capsule could be, roughly, replaced with 15 kg of hydrazine, so you'd have a 15 kg mass saving here, but in general actual engineering calculations are harder. I wish they wouldn't be such.
Given those very crude estimations and the practice, which shows there are no big unforeseen problems, we have a valid arguments for the alternative. It's an engineering argument, an estimation and not necessarily full calculations, and it's not effectively an arbitrary opinion. You may finally decide the issue using hard numbers, but since we don't have them now, the question stands.
What would be the options? Compressed cold-gas (which don't have much kick, and require compressed gas which carry their own dangers).
You could go with a monoprop Hydrazine which would eliminate half the toxic stuff. There are also some new developments here: hydroxylammonium nitrate (HAN)/water/fuel ? No idea of the trade offs there.
Biprop hydrocarbon/gaseous compressed oxygen? Presumably that'd require an ignition source (and power source). How do you see that trade off?
Do you consider high-test peroxide non-toxic? (It certainly has a different risk profile, but is nasty stuff on contact with about anything that can oxidize). The decomposition would also make storage and rotation a consideration.
Soyuz uses straight hydrogen peroxide, I believe, 82% concentration. For 3 tons capsule it takes 30 kg of peroxide - monopropellant - to land.
Buran is still the example of a high tech option - it used LOX and kerosene for RCS, the biggest trick was to keep LOX liquid for a month-long missions. It was done with mid-1980 technologies.
Kliper planned to use LOX and ethanol. The craft wasn't completed in metal though.
One has to remember that hydrogen peroxide - the rocket concentrations are called HTP, high test peroxide - can be used as an oxidizer, after a catalytic decomposition - and after decomposition HTP is easily hypergolic with fuels. "Hypergolic" doesn't mean "nitrogen-containing, long-storing and toxic", it means "self-igniting" - and it could be non-toxic (or at least HTP toxicity is on the whole different level that hydrazine's one).
To come back from orbit you don't need too much delta-V. So Soyuz uses 30 kg of peroxide, maybe it would use 15 kg of hydrazine for the same effect - you're saving 15 kg in a 3 ton spacecraft but losing on toxicity. Similarly, Crew Dragon is a heavier craft, flying on a bigger F-9 rocket, it can probably allow for some extra mass spent for RCS fuel in order to make it non-toxic.
> You could go with a monoprop Hydrazine which would eliminate half the toxic stuff.
Hydrazine is, I think, a way bigger half. NTO is comparatively benign... not so carcinogenic. But still lethally dangerous :( .
> Biprop hydrocarbon/gaseous compressed oxygen?
Was done at least. Yes, it would require extra systems. You think it can't be done?
> Do you consider high-test peroxide non-toxic?
Comparing to hydrazine - yes.
> The decomposition would also make storage and rotation a consideration.
Yes. Have to chill it, take care while in storage and keep tanks extra clean. But still.
The toxicity of NTO is bad, extremely so, and everyone knows it. But having your oxidizer tank suddenly go boom on its own accord is even worse.
Curious about the spacesuits and performance of the “minimal” touchscreen interfaces compared to the older stuff.
The touchscreen interface is "different" - the astronauts talked a bit about helping SpaceX design it and the pros and cons of it in a recent interview. I wrote it up here but you can also check the original long NASA TV thing.
https://techcrunch.com/2020/05/04/this-is-certainly-differen...
https://www.youtube.com/watch?v=hxCzpa07dvg
I used to watch old space mission videos and I think how could it would've been to watch them live back in the day.
Now SpaceX has brought this excitement back.
https://youtu.be/7cyoZ71lzEk
I wish I could have been there at the time, and today was the next best thing. Truly amazing.
> Lifting off from Launch Pad 39A atop a specially instrumented Falcon 9 rocket, Crew Dragon will accelerate its two passengers to approximately 17,000 mph and put it on an intercept course with the International Space Station. Once in orbit, the crew and SpaceX mission control will verify the spacecraft is performing as intended by testing the environmental control system, the displays and control system and the maneuvering thrusters, among other things. In about 24 hours, Crew Dragon will be in position to rendezvous and dock with the space station.
Would you get a reference to M&Ms? I know SpaceShip1 was 16 years ago now. How time flies.
I still remember when I was very little and my dad took me to a launch once.
Hope manned rocket launches will get more regular again and seeing them will inspire a whole new generation.
This is the Apple II moment of space travel: when megacorporation giants were squeezed out of the market in a few short years by some dudes working out of their garages.
However watching that it's cool to see cutting edge tech rather than the 1960s style stuff. Also hopefully this is just a step for SpaceX on the way to Mars and beyond.
https://www.nasa.gov/feature/mrap-rolls-through-pad-evacuati...
If you want the closest view of a launch without being in the rocket, get some firefighting experience (preferably on an aircraft carrier or something of similar hazard) and then ask your senator to recommend you as a qualified guest firefighter.
And there is the problem that we have stalled quite a bit in engine development.
Apparently:
Musk plans to send a SpaceX rocket to Mars, with cargo only, by 2022, according to the SpaceX website. A second mission, which would take more cargo and crew, is targeted for 2024
So, realistically, 2030?
However the mission to Mars isn't a direct linear descendant of this so it may slip more or less.
Great graphics and timelines of the mission can be found here.
This is what a Martin Baker ejection handle looks like: https://c8.alamy.com/comp/BJTDWG/martin-baker-ejection-seat-...
With all due respect to all the engineers that work at SpaceX, the UI of the cockpit has regressed to the point of pure marketing. Same with the suit design, looks like an awful low budget sci-fi film. Functionalism and the beauty in the way things are without adornment is dying. And, it is painful to watch as a engineer who designs HMI systems. IMO design and aesthetic that emerge out of the way things are is so much more authentic than CEO's inspiration from a sci-fi movie genre that was probably conceived by some guy in 80's in half a dozen hours before before putting up a hollywood set. These movie makers did not study UX/UI and it was all about entertaining the audience.
Just look at how functional and beautiful the aesthetics of space flight was like during the golden era of Apollo 11. There was no design. There was just pure emergence of aesthetics from whatever they were doing to make things functional (ok, with some small exceptions like the logo and US flag on the suits): https://www.youtube.com/watch?v=tpLrp0SW8yg
Checkout the new Mars rover - absolutely zero marketing, pure function - https://mars.nasa.gov/news/8649/nasas-perseverance-mars-rove...
If SpaceX designed a mars rover, it would have gaudy shrouds and plastic covers, probably some LED lights to make it look cool, sleek 30, 45, 60 degree angles everywhere (ohhh space aesthetics), and all kinds of marketing bullshit whereas NASA engineers are focused on what is important. And it is gorgeous without even trying.
They sent voyager up with the Golden record. Those dumb engineers wasted precious mass on something purely for sentimental value.
Also compare with other abort modes Shuttle was a dial https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes#/med...
If something doesn’t work, SpaceX will fix it. You really don’t give their engineers enough credit.
Or a high budget sci fi film, or a medium budget sci fi film, since literally every film involving a spacesuit ever made had a more reasonable design than the utterly ridiculous, cumbersome, and bulky Hamilton Standard design American astronauts were stuck with for such a long time.
Of all the possible critiques of SpaceX, an attack on the new space suits is a genuinely weird one.
It's mostly just that older suits [0] and scifi suits [1] have painted a picture of there being more stuff involved in a suit to break up the expanse of the torso and the back, so they look weirdly plain. I bet they're perfectly fine functionally, and the single port seems like a good idea, but the do kind of miss the mark for me aesthetically.
Also really hope they figure out how to make flexible necks work because this [2] video of them trying to look to the top of their rocket looks so uncomfortable.
[0] https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/AC...
[1] https://www.theverge.com/2017/8/19/16104004/science-fiction-...
[2] https://youtu.be/rjb9FdVdX5I?t=5819
In an article[1] a month ago, Bob said "I don’t think I’m going too far out on a limb to say that the right answer for all flying is not to switch to a touchscreen, necessarily. But for the task that we have and to keep ourselves safe flying close to the ISS, the touchscreen is gonna provide us that capability just fine."
Doug explained "The difference is you’ve got to be very deliberate when you’re putting in input, relative to what you would do with a stick. Because you know, when you’re flying an airplane for example, if I push the stick forward it’s going to go down. I actually have to make a concerted effort to do that with the touchscreen, if that makes sense."
So it sounds like there's more cognitive overhead to use the touch interface for flying. I did think the touchscreen was perfect for the procedure checklists shown extensively in the middle console during today's flight.
In the on-board media event a few minutes ago, he pointed out "One thing that does get lost is there is an extensive button panel down below."
[1] https://techcrunch.com/2020/05/04/this-is-certainly-differen...
A stick while flying is useful for weather, but there's no weather in space. In space, a stick probably provides little feedback.
Yet think it makes for a good HN post to "facepalm" at their decisions.
"It's great, I'm so happy, we are all happy family. We had say on how these things work." Wait until they retire to find out the truth.
BTW - On Soyuz they would need sticks, literal sticks, to interact with controls that are out of reach.
Interested what exactly isn't functional about the suits? Most of this post seems to be entirely about looks and outward appearances alone.
https://youtu.be/rjb9FdVdX5I?t=5819
The advent of additive machining means everything doesn't have to be right angles and hard corners.[1] As a result the cabin will be safer because your astronauts are less likely to be hurt if there is an unanticipated thrust. Parts can also be made to fit better and to closer tolerances.
With regard to the suits - they look far better than the orange shuttle flight suits. I think that having the umbilical on the thigh was a good innovation. No idea how comfortable they are, but they're only going to be worn for launch & entry. I expect Doug & Bob have already put their shorts & t-shirts on.
https://airandspace.si.edu/stories/editorial/spacex-dragon-l...
[0] I'm a tiny bit disappointed that they didn't go for a 2001 design, with Eurostile Bold Extended fonts. https://typesetinthefuture.com/2014/01/31/2001-a-space-odyss...
[1] Which is the same reason why shift levers in cars are being replaced by knobs and switches - so the passengers don't get hurt by them in an accident.
I don't think so, they're using the screens for docking too according to their own site. [0] You can do the same basic task the pilot would be doing during a manual approach from what I think is Waypoint 1 (meaning Dragon is in front of the ISS pointed mostly towards it). You can see the actual text on the buttons here [1] and they're all critical system tasks like power cycling the controllers, aborts/emergency response commands, or manual triggers for things during landing.
[0] https://iss-sim.spacex.com/
[1] https://www.nasaspaceflight.com/wp-content/uploads/2018/08/2...
https://space.stackexchange.com/questions/9243/what-computer...
I'm shifting uncomfortably in my chair just reading that
Personally I found the lack of analog input control harrying toward the end. A toggle between "large" and "normal" thrust mode is all you get. Normal felt like it wasn't fine-grained enough.
Moreover, how long until we get a "brought to you live by starlink" banner?
Then we have launches straight to geostationary orbits and similar, for those the second-stages will essentially never come down and they end up positioned in a graveyard orbit.
https://hackaday.com/2018/05/23/spacexs-next-giant-leap-seco...