TEGA - Round 2 Options

[01101001]

TEGA oven #5 not full yet

NASA Phoenix Mission News: Soil Studies Continue at Site of Phoenix Mars Lander (2008 August 9)

"There appear to be clumps blocking the opening," said Doug Ming of NASA Johnson Space Center, Houston, the Phoenix team's science lead on Friday. "However, we have seen in the past that when this soil sits for a while, it disperses. We intend to fill an oven with this material, either by additional vibration of the same screen or by opening doors to one of the other TEGA cells."

[ZenDraken]

Wouldn't it be simpler to devise something to blow the area clean after each experiment? Seems to me it'd be difficult to get suction in a near vacuum.

--Greg

A compressed air system would add considerable complexity, weight, and power demand. But a small brush would work and be really simple and lightweight.

I keep saying robotic missions should include some basic tools. These would have been really handy on Phoenix:

1. A prybar: just a metal probe, to push, pull, pry, or whatever's needed. (forcing open TEGA doors)
2. A brush for general cleaning, (like cleaning TEGA). Another brush mounted to the lander somewhere would be handy for cleaning sticky stuff out of the scoop.

These could have been permanently built-in to the RA, perhaps on the back of the scoop, no need for extra moving parts.

A hammer of some sort might be useful but would probably require a solenoid actuator, which means added complexity, weight, and power draw. Always KISS (Keep It Simple Stupid) or you're just adding problems.

[ilbasso]

Don't forget duct tape. Can't go on a long trip without duct tape. And a Swiss Army knife.

[djellison]

Always KISS (Keep It Simple Stupid) or you're just adding problems.

That's exactly how I would describe your entire suggestion.

Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.

Doug

[JRehling]

What about just having the surface be sloped 45 degrees? Try to beat that for no-moving-parts.

[ElkGroveDan]

I keep saying robotic missions should include some basic tools. These would have been really handy on Phoenix:

Even better, the Opportunity lander should have included some wire, automated pliers and a soldering gun. Then it would have been able to fix the short that kept the arm heater on. Spirit should have included a power wrench so they could have removed the stuck wheel. The Mars Climate Orbiter should have included a subroutine that responded with "Are you sure you meant to send those orbital insertion instructions in imperial units and not metric?" And of course, we all know Apollo 13 should have had spare oxygen tanks and a redundant secondary electrical system.

[Juramike]

Or how about just a simple paper clip? Works for MacGyver....

MacGyverisms

[gallen_53]

Even better, the Opportunity lander should have included some wire, automated pliers and a soldering gun. Then it would have been able to fix the short that kept the arm heater on. Spirit should have included a power wrench so they could have removed the stuck wheel. ..

How about: Send along an astronaut and if something breaks, he/she can fix it.

[BrianL]

Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.

That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.

[Greg Hullender]

Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.

Hardware's not my strong suit, but is it truly so difficult to have multiple attachments on the robotic arm? I can see how multiple scientific instruments would be tough, but "dumb" attachments like a pick and a brush don't seem like they should sink the boat.

Anyone know if anything like that was even considered?

--Greg

[Deimos]

Anyone know if anything like that was even considered?

Similar things were considered, such as a scoop brush. The scoop currently has a drill and a TECP. It is near a camera. Any scoop-end device would have to be dealt with in ops--TECP greatly complicates RAC and limits how close to the surface it can take pictures. Put a brush near it, make the brush stay clean when the TECP is inserted, and I could see you might have problems. Then you have to deal with degrees of freedom--using a wrist-mounted brush to clean TEGA would be tricky. You have 6 degrees of freedom with something held in your fingers, which is enough to hold something where you want it, oriented how you want it. The most you can get out of the RA is 4 degrees of freedom, you you have a trade between where you want it and how you want it aimed.

[Stu]

Don't forget duct tape. Can't go on a long trip without duct tape. And a Swiss Army knife.

... and a towel. Space travellers should never go anywhere without a towel, as the Guide says.

[djellison]

That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.

And that is an utterly lousy call given that we have successfully delivered two sample, and have plenty of opportunities left to deliver more.

[Juramike]

That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.

I disagree.

Cooking and sniffing the subsurface of Mars is the reason Phoenix went there in the first place.

[BrianL]

Of course TEGA is a necessary instrument. The suggestion was tongue in cheek. I simply felt that, with his challenge, Doug opened the door for injecting a bit of criticism.

Edit: I've taken out some additional comments. I'm a bit crankier than usual from having buggered up my back yesterday, cleaning algae off the fish tank, of all things.