Are there any drawbacks or potential dangers using touchpads on spacecraft?

[Ganesh Ujwal]

Are there any drawbacks or potential dangers on using touch-sensitive instrument panels on spacecraft ?
Just as seen on Orion and Dragon designs (I haven't checked on other current spacecraft s), there are a lot of benefits from using touch-sensitive panels instead of traditional electrical switches.

Some benefits might be:

• Less wiring and less clutter, hence more space in the module and less weight
• Less risk of electrical/mechanical malfunction, electrical fire, etc.
• More intuitive interface
• Ability to update firmware/software
• language translations on UI (could come in handy for multi-cultural teams)
• Many others...

Now, having said that, what could be some potential dangers or drawbacks from using this design instead of classical electrical switches?

 

[zyxwv99]

Anything that goes into space needs to be robust enough to withstand cosmic rays. That's why computer chips that go into space are usually of the older variety with thicker connections.

Mechanical devices such as buttons and switches are more intuitive. You can feel them when they click into place. They don't change what they do because someone updated the software.

Some of this has to do with industrial psychology, for example, beer handles in bars to ensure that the bartender never pours the wrong beer. Those beer handles were traditionally installed in nuclear power plant control rooms (attached with electrical tape) to make sure somebody didn't pull the wrong switch at the wrong time.

If you can come up with a touch-screen design that has seen at least a billion hours of service (cumulative for all users) with absolutely no changes to the hardware or software, and if it's performed well, then maybe there would see the beginnings of a discussion.

 

[mp3car]

An example where Boeing has used a touchscreen recently is in the KC-46, and some of it's commercial aircraft... Both for cabin control as well as aerial refueling... Additionally, Electronic Flight Bags (EFBs) are sometimes touchscreen, the iPad being one of them.

http://www.upi.com/Business_News/Se...uch-screen-control-panels/UPI-67761316168881/

http://www.military.com/daily-news/...w-tankers-first-flight-delayed-by-months.html
"The cockpit* is built with 24-inch 3D, digital displays equipped with touch screen capability. The aircraft enables crew members a 185-degree field of view and has low-wave infrared cameras."
*NOTE: This is an error in the article. The cockpit doesn't have 24" 3D panels, they are used by the aerial refueling operator, not the pilots. The refueling operator's station is located behind the cockpit (vs. at the back of the KC-135 where the boom operator lays down looking out a window; the KC-46 uses stereoscopic cameras).

A touchscreen technology I have worked with (I work for aerospace company) is called Surface Acoustic Wave, or SAW. One neat thing about this technology is that it can give not only X-Y coordinates, it can also give a Z dimension - force of the users touch. A possible use could be when holding up/down arrows, a harder touch could scroll faster.

 

[Jonathan Scott]

I would have thought that without being firmly strapped in, a touch screen could be a bit tricky to operate without places where the hand or fingers could safely rest, but I guess it might not be as difficult as the buttons were in Skylab, which the astronauts found difficult to use because pushing a button moved them backwards. I would have also thought it a good idea to protect any important controls by disabling them when not in use to prevent them being bumped by accident, and that is certainly probably easier for software-defined buttons.