Dragon v2 Kremlinology from Helodriver's unveiling pics

[Comga]

If you look closely at the outer rim of pic #3 there's what looks like a white O-ring type seal, and I'd bet that thick black band is part of an inflatable pressure seal.

Seen those before in isolation and biohazard labs. 'Inflatable seal (or gasket) door'. Also dynamic seal. IIRC they can also be used in water-tight hatches for marine applications. In this application those are likely the passive side seals with the inflatable active side seals in the door frame. Easier to plumb the gas  supply there.

Once those seals inflate it's going absolutely nowhere, locked tight as a drum - with or without locking pawls. Ditto for any gas flow.

I've used inflatable seals for both underwater robots and pressure suit entry mechanisms. They work well if you can continually pressurize them, but are a potential source of leaks. They also aren't all that solid if loaded in shear, since they are made of elastomers. Even assuming they're using an 8.3 psi cabin pressure, it's still about 3500 pounds of force trying to open the door. I definitely think you would absolutely want mechanical latches, even with an inflatable seal.

I realize that your point is even more valid at higher pressure but where did you get the value of "8.3 psi cabin pressure"?
That's not the interior pressure of the ISS, which is (a fairly heavy for some of us) 14.7 PSI.

[CraigLieb]

Another reason they [Orion team] stated was touch screen would be difficult to use with space glove on. Would like to see how well astronauts can operate the screen via simulation to find out the real deal.

Easy. There is no reason that space gloves can't have inductive fingertips.
I have seen people wearing such gloved fingertips, to keep fingerprints off the screen.
They work great.

Legacy equipment mindset looses another one.

Even in my experience from the 1980s, there were a number of technologies to chose from for touch technology including  multi-layer contact based film systems, acoustic (sound based), capacitive/resistive  (based on changes in electrical properties on a grid), and IR based (breaking the beams which required a deep frame around the panels). 

I have no idea which of these, or others that may be applied today in the V2 displays, but some of them would work quite well with gloves.  With the correctly sized graphics acting as virtual buttons, and the right de-bounce software, they could be viable controls for non-life critical actions like choosing which display format to place on the screen.

[pagheca]

Another reason they [Orion team] stated was touch screen would be difficult to use with space glove on. Would like to see how well astronauts can operate the screen via simulation to find out the real deal.

And what about a situation like the Apollo 12 "Try SCE to aux"? It is true there are some mechanical emergency switches, but what if something like that happens? Would an astronaut be able to quickly and correctly press a switch, or a sequence of switches, with the cabin under high vibration or high-g accelerations, also if bare handed?

Just a question. Obviously they must have considered this situation.

[Elmar Moelzer]

Another reason they [Orion team] stated was touch screen would be difficult to use with space glove on. Would like to see how well astronauts can operate the screen via simulation to find out the real deal.

And what about a situation like the Apollo 12 "Try SCE to aux"? It is true there are some mechanical emergency switches, but what if something like that happens? Would an astronaut be able to quickly and correctly press a switch, or a sequence of switches, with the cabin under high vibration or high-g accelerations, also if bare handed?

Just a question. Obviously they must have considered this situation.

There are manual emergency switches for all vital systems.

[pagheca]

There are manual emergency switches for all vital systems.

Thanks Elmar.

Yes, I know (and I wrote that) there are manual switches. But was for example the SCE switch on the CM considered vital at the time? I don't think so, and in fact neither Pete Conrad or anyone else in the MC or on board except Aaron and Bean remembered about that: the abort switch was the actual "emergency switch", at least for that situation.

So, ok: time passed and system engineering is much more refined today. But I wonder how they will manage the copious unpredictable procedures that may be required through a touch-screen in high stress situations.

Again, obviously they must have managed this. I wonder HOW.

[john smith 19]

Operational hatch handle will likely resemble aircraft exterior doors, like this:

And note the hinge design, exactly like that on Dragon

[cscott]

So, ok: time passed and system engineering is much more refined today. But I wonder how they will manage the copious unpredictable procedures that may be required through a touch-screen in high stress situations.

Again, obviously they must have managed this. I wonder HOW.

Testing, obviously.  Even "unpredictable" situations are usually a combination of known procedures.  They have astronauts on staff, who probably spend a lot of time running simulated failures of various kinds.  Consider that the procedures checklist on shuttle often involved typing inscrutable digit combinations into a manual keypad.  It's not too different from hitting different buttons on an on-screen display.  The important thing is *practice* and muscle-memory, so that the behavior is automatic.  The cognitive load isn't all that different.

Even in my experience from the 1980s, there were a number of technologies to chose from for touch technology including  multi-layer contact based film systems, acoustic (sound based), capacitive/resistive  (based on changes in electrical properties on a grid), and IR based (breaking the beams which required a deep frame around the panels). 

In my previous job we brought a children's laptop with an IR-based touchscreen to production.  IR-based touchscreens went through some exciting technology development recently; some versions of the kindle use them, for example.  They are very good for gloved/ungloved use, and with various size "touch points".  In our application it was also a plus that they are very robust in the face of kids using them with sticky fingers, splashing stuff on the screens, etc.  They are also easy to integrate because the touch sensing mechanism doesn't have to be transparent and sandwiched in front of the visual display.

No idea if SpaceX is using IR sensing, of course -- it's still mildly exotic.  But I'm supporting your general point that there are *lots* of different touch screen technologies out there, with different strengths and weaknesses.  Just because you hear "touchscreen" you shouldn't assume that it works exactly the same way your iphone does.

(Oh, and the "deep frame" is only about 1/8".  Here's a picture -- note that the touchscreen part is *not* the white bezel, it's the black (IR filter) plastic between that and the screen.)

[rlmoser]

Also, it's bad practice, in my opinion, to have the O2 and CO2 levels indicated on 0 - 100% scales. A quick search on the web shows that, from a health perspective, O2 should be between 19% and 24% and CO2 should be less than 0.6%. The indicators should be scaled accordingly.

O2 and CO2 figures listed are in the ranges you indicated as normal.

It wasn't the figures that he was taking issue with, but the bar graph under the figures.  With it scaled from 0-100% you'll pretty much never see any difference in the bar under the CO2 indicator, and very little in the O2 indicator.

[CraigLieb]

...

(Oh, and the "deep frame" is only about 1/8".  Here's a picture -- note that the touchscreen part is *not* the white bezel, it's the black (IR filter) plastic between that and the screen.)

In the 1980s the frame was around 1.5 inches... How Tech marches on.

[Sean Lynch]

There are manual emergency switches for all vital systems.

Thanks Elmar.

Yes, I know (and I wrote that) there are manual switches. But was for example the SCE switch on the CM considered vital at the time? I don't think so, and in fact neither Pete Conrad or anyone else in the MC or on board except Aaron and Bean remembered about that: the abort switch was the actual "emergency switch", at least for that situation.

So, ok: time passed and system engineering is much more refined today. But I wonder how they will manage the copious unpredictable procedures that may be required through a touch-screen in high stress situations.

Again, obviously they must have managed this. I wonder HOW.

Oh ye of little faith; hast thou not viewed process control from a modern software engineering paradigm?
Go now an contemplate the appropriate button for the blue screen of woe and have faith in the systems engineers.

[pagheca]

Oh ye of little faith; hast thou not viewed process control from a modern software engineering paradigm?
Go now an contemplate the appropriate button for the blue screen of woe and have faith in the systems engineers.

do you mean something like this, except you don't have two hours and half to remain "dead in the air" while an astro-tug comes and collects you?

[Lar]

What you prefer? Metal on metal seals?

I don't have a preference[1], I was asking a question.

He said "Most of what you see here is flight hardware." (emphasis mine). Do we really have to have 18 pages filled with pointless speculation on things like pressure seals being absent from the hatch of a mostly flight hardware new Dragon V2?

You're new around here, aren't you?   ... of COURSE we are going to have 18 pages filled with speculation.

In my previous job we brought a children's laptop with an IR-based touchscreen to production.  IR-based touchscreens went through some exciting technology development recently; some versions of the kindle use them, for example.  They are very good for gloved/ungloved use, and with various size "touch points".  In our application it was also a plus that they are very robust in the face of kids using them with sticky fingers, splashing stuff on the screens, etc.  They are also easy to integrate because the touch sensing mechanism doesn't have to be transparent and sandwiched in front of the visual display.

You worked on OLPC[2]? That's AWESOME.


1 - Before I read some of the posts following yours I would have answered "rubber, but not inflatable rubber" but some point out that rubber that has to be compressed strains the hatch more than rubber that inflates to fill the space but isn't compressed by the hatch...

2 - http://en.wikipedia.org/wiki/One_Laptop_per_Child

[Jdeshetler]

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

[pagheca]

Testing, obviously.  Even "unpredictable" situations are usually a combination of known procedures.  They have astronauts on staff, who probably spend a lot of time running simulated failures of various kinds.  Consider that the procedures checklist on shuttle often involved typing inscrutable digit combinations into a manual keypad.  It's not too different from hitting different buttons on an on-screen display.  The important thing is *practice* and muscle-memory, so that the behavior is automatic.  The cognitive load isn't all that different.

cscott, do you think that obviously you can reproduce any fault that requires split seconds intervention and save the mission by pressing one of the 30 (I counted them) buttons available in the V2 main console withouth having to push the "abort" one (if exists) at the first real malfunction in a critical situation?

Look at the cockpit of a state-of-the-art 787:

(hundreds among switches and knobs)

or of a F-35 Lightening:

(many tenths switches and knobs)

With all my enourmous respect for EM and his great Company, after having thought twice about, I guess that the number of switches on the V2 flight article will be closer to the one on the Dreamliner than on the one shown in this demo.

I can't really believe they can pass from the >1000 switches in a Shuttle cockpit to 30, or even 100, in one shot, without missing just 'that' vital switch requiring split-second attention in that particular emergency mode. Even considering - correct? - the reduced functionality and requirements of a Dragon V2 respect to a Space Shuttle Orbiter.

Alternatively, don't the experts think they are really stretching technology expectations? Or I'm really missing something here?

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

Why do you think the temperature on the cockpit should go so low under vacuum in normal operating conditions?

[Jdeshetler]

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

Why do you think the temperature on the cockpit should go so low under vacuum in normal operating conditions?

A piece of bare metal in space, under constant sunlight can get as hot as two-hundred-sixty (260) degrees Celsius. And yet, in the shade, an object will cool down to below -100 degrees Celsius.

http://www.universetoday.com/77070/how-cold-is-space/

[pagheca]

A piece of bare metal in space, under constant sunlight can get as hot as two-hundred-sixty (260) degrees Celsius. And yet, in the shade, an object will cool down to below -100 degrees Celsius.

http://www.universetoday.com/77070/how-cold-is-space/

Right, but at the condition that the piece is not heated. A touch screen and the whole cabin must emit some power in order to function. Vacuum is an excellent thermal insulator, and the cabin looks probably as a black body cavity.

[cscott]

You worked on OLPC[2]? That's AWESOME.

Yup.  @jg is hanging around these parts, he's an OLPC alumnus as well.

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

No physical reason why they cannot be.  Assuming they are LED (not LCD), it's all just solid state transistors and some transparent plastics.  (For our part, we only rated our machines down to "walking to school in outer Mongolia" temperatures.)

cscott, do you think that obviously you can reproduce any fault that requires split seconds intervention and save the mission by pressing one of the 30 (I counted them) buttons available in the V2 main console without having to push the "abort" one (if exists) at the first real malfunction in a critical situation?

I'm not sure what point you're trying to make.  Finding the "right" switch in the maze of of a 787 -vs- drilling down on a touchscreen right in front of you?  Comparing the severity of "touchscreen failure" in a Dragon v2 -vs- in a F-35?  Or are you just upset that the computer is likely to be better at reacting to and flying failure modes than a human pilot?

[beancounter]

You worked on OLPC[2]? That's AWESOME.

Yup.  @jg is hanging around these parts, he's an OLPC alumnus as well.

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

No physical reason why they cannot be.  Assuming they are LED (not LCD), it's all just solid state transistors and some transparent plastics.  (For our part, we only rated our machines down to "walking to school in outer Mongolia" temperatures.)

cscott, do you think that obviously you can reproduce any fault that requires split seconds intervention and save the mission by pressing one of the 30 (I counted them) buttons available in the V2 main console without having to push the "abort" one (if exists) at the first real malfunction in a critical situation?

I'm not sure what point you're trying to make.  Finding the "right" switch in the maze of of a 787 -vs- drilling down on a touchscreen right in front of you?  Comparing the severity of "touchscreen failure" in a Dragon v2 -vs- in a F-35?  Or are you just upset that the computer is likely to be better at reacting to and flying failure modes than a human pilot?

There's also something called flight simulations and training that I believe is used extensively in commercial aeronautics and just perhaps might be transferrable to aerospace.
Cheers

[Coastal Ron]

Will the touchscreen monitors survived and be touchable during vacuum environment at very low temp if they had to open the hatch to go EVA from the Dragon V2 in the distant future?

Depends on the touch technology, but I would think it would be capacitive like an iPhone.  That would mandate conductive gloves, but that is becoming the norm anyways.

As for a vacuum, I would think the displays are housed in a sealed enclosure, and the glass over the display can withstand a full vacuum.  Though I don't think that full vacuum is a normal operating mode, so it would only be for emergency conditions.

Orion's displays will have the same challenges, especially since the Orion is meant to vent the cabin on some missions.

[pagheca]

I'm not sure what point you're trying to make.  Finding the "right" switch in the maze of of a 787 -vs- drilling down on a touchscreen right in front of you?  Comparing the severity of "touchscreen failure" in a Dragon v2 -vs- in a F-35?  Or are you just upset that the computer is likely to be better at reacting to and flying failure modes than a human pilot?

Don't misinterpret what I said: I'm not upset, really, I just have a genuine will to understand how this kind of new interfaces may work in such a challenging environments (and like to joke a little bit... ).

If I have a mechanical "3D" switch i can grab it and push on it even in a very stressful environment, feel the movement and the vibration of the mechanism. If this is just an area of a screen the feedback is not the same.

If there is smoke in the cabin, I can still grab the last button in the row, count the third left and press it.

When I type something on my iphone... android,  the shape of the key do not help to "reset" the position of my hand and the fingers may shift continously If I do not watch the keyboard.

Typing a sequence of characters may be even more challenging.

I just imagine problems like these... But it's probably just a mental habit, or plain ignorance of technical or ergonomic solutions available today in aerospace interfaces like those ones.