MSL schedule delay? Options

[elakdawalla]

Very short statement. Decision is to continue unabated with launch as planned in 2009, despite delays in deliveries of both hardware and software. Now it's Q and A time. Not authorized to talk about budget numbers.

--Emily

[centsworth_II]

"The descent stage, otherwise known as the sky crane."

!!!???

[ChrisC]

Grrrr, the promised streaming http://www.nasa.gov/newsaudio is not working.

[elakdawalla]

You're not missing much. It's not too informative. On the most important question -- how much is this going to cost, and where is the money coming from -- they are being silent, because they haven't resolved where the money is going to come from yet.

--Emily

[Stu]

I can't get on either... Never mind, not the hand grenade we were expecting. Thanks for passing on the news, Emily.

[elakdawalla]

The biggest thing causing both budget and schedule pressure is the actuators (motors), which still have not been delivered. These include motors for the arm, for the sample handling mechanism, and the wheels, both rotators and wrists. At present they expect their delivery in late November.

--Emily

[imipak]

Phew, that's a rare bit of good news. (I hope it's not bad news for other missions, of course.) Would anyone care to offer (informed?) speculation on what features of these actuators could be unusual enough, engineering-wise, to cause unexpected delivery delays?

[punkboi]

Woohoo! Here's hoping everything is still looking good in January...when NASA takes a look at the mission's progress again

[centsworth_II]

...what features of these actuators could be unusual enough, engineering-wise, to cause unexpected delivery delays?

I would say the main feature is that they are unique -- and complex --mechanisms for a unique machine. And they need to be built and tested to be as near flawless as possible... no repair shops on Mars. I heard a figure of 600 parts mentioned for 'some of these'. I don't know if that is moving parts, or if it is the actuator only or includes the wheel assembly or joint being moved. But either way, that's really complex.

[elakdawalla]

The weight of MSL is the main problem. One specific issue they cited is that titanium gears couldn't bear the stress -- they had to switch to stainless steel. Also, early on in MSL's development, they had planned to have actuators that used a dry lubricant. But the development of the dry lubricant failed, so they had to redesign to have actuators that used a wet lubricant, which also means they have to be heated. The actuators have been an unending headache on this mission.

--Emily

[centsworth_II]

"Among the major hardware problems: the actuators, or motors, on the robot. McCuistion said that there were more than 600 parts in some assemblies. Key areas were at the 'complicated' shoulder and wrist joints, he explained. The actuators are made by Aeroflex, a New York company. McCuistion characterized the company as providing "excellent" work and said that actuator problems were a reflection of the complexity of the robot's construction." http://www.examiner.com/x-504-Space-News-Examiner

[imipak]

( <snip!> lengthy ramble about the need for flawlessness in s/c, by analogy to information security (Valdis puts it much better than I can, anyway...) )

Thank-you both, that was exactly the info I was wondering about. I didn't mean to trivialise the complexity or difficulty of the endeavour - if it was easy, everyone would be doing it! I was just curious about the details.

[ustrax]

Fantastic piece of writing Emily!

Regarding the news, I just hope that the pressure put over the people working with their hands on MiSheLle won't lead to errors that can endanger any stage of this mission, being it the launch or operations already on Mars.

Stay focused and do what you do best guys!

[Norm Hartnett]

http://www.lpi.usra.edu/pss/presentations/...10/greenMSL.pdf

[Guest_Bobby_*]

From yahoo news.

No Delay from Nasa regarding MSL:

http://news.yahoo.com/s/ap/20081010/ap_on_...ars_science_lab