MSL should have a digging arm

[willpittenger]

Mars Phoenix Lander (not to be confused with Mars Polar Lander) will have an arm for digging a trench to determine what lays below the surface. However a rover with the same arm (like MSL) would have the following advantages over MPL's arm:<ol type="1"><li>The rover can dig many trenches across several miles of terrain.<li>The rover could move around to expand a trench from different areas.<li>The rover could slope the sides of a large hole to allow it to go down inside to go even deeper (like a strip mine) or to allow it to extend its instruments into a hole (perhaps a natural one) where they would not normally reach.</li></li></li></ol> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[no_way]

did you read about Regolith Excavation Challenge ? One of the fundamental problems they are trying to address with it is how to dig with very weak power available. The "excavators" there got only 30 watts of power. Thats in the range of bigger hobby servos or toys. Electric RC models pull more, occassionally much more than that.<br /><br />Now mobile rover will likely have smaller solar panels and thus less power available. So digging those miles of trenches will either take ages, or you need better source of power.<br /><br /><br />EDIT: i'll make this post more useful and post the link of the more detailed news report on it:<br />http://www.santamariatimes.com/articles/2007/05/13/news/centralcoast/news03.txt<br /><blockquote><font class="small">In reply to:</font><hr /><p><br />But the strict parameters - machines also could use only 30 watts of power and had to weigh less than 88 pounds as they excavated the simulated moon dirt - defeated the competitors.<br />For nearly 30 days straight, Greenhaw created an excavation machine that did well lifting sand and clay. Somehow the machine only managed to lift roughly 150 pounds of JSC-1A. He blames the competition criteria.<br /><br />“No matter how efficient your machine is, the criteria of the challenge makes it almost impossible,â€<br /><p><hr /></p></p></blockquote>

 

[gunsandrockets]

<Now mobile rover will likely have smaller solar panels and thus less power available. So digging those miles of trenches will either take ages, or you need better source of power.><br /><br />Odds are the MSL rover will be a powerhouse compared to the Mars Phoenix Lander since the MSL is more than twice as heavy as the MPL. And odds are the MSL rover will use nuclear RTG power instead of solar power panels.<br /><br />correction posted - I originally wrote Mars Polar Lander instead of Mars Phoenix Lander<br />

 

[no_way]

even more detailed story on the actual machines in regolith challenge this year:<br />http://www.newscientist.com/blog/space/2007/05/moon-dust-4-inventors-0.html<br /><br />how many of you here are competing next year ? <img src="/images/icons/wink.gif" /> it aint rocket science, and one guy there said he put his machine together for $400 or so. The prize purse next year will be half a million IIRC

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>odds are the MSL rover will use nuclear RTG power instead of solar power panels.<p><hr /></p></p></blockquote><br />dont get too excited. i think its already decided that MSL will have MMRTG onboard, producing somewhere in the neighborhood of .. 110 watts or so at the beginning of the mission. <br />Thats roughly the same as MER's have available at peak<br />

 

[jimfromnsf]

"dont get too excited. i think its already decided that MSL will have MMRTG onboard, producing somewhere in the neighborhood of .. 110 watts or so at the beginning of the mission.<br />Thats roughly the same as MER's have available at peak "<br /><br />It was decided long ago but only officially acknowledged last year.<br /><br />MSL will run on batteries that will be recharged by the MMRTG

 

[3488]

MSL will also carry out night time observations & carry out rudimentary Astronomy from Mars as has the MERs. <br /><br />Yes, it would be disirable for MSL to have a trenching arm, as did the Viking Landers, but it looks as if power budgets, <br />have to trade trenching OR roving.<br /><br />Clearly roving is taking priority, but the Mars Phoenix Lander in some ways is harking bach to the Viking landers, <br />in that trenching will be carried out & that the results will be photographed.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[no_way]

btw, it seems to me that MSL _does_ have a digging arm planned<br />http://photojournal.jpl.nasa.gov/catalog/PIA09201<br />http://photojournal.jpl.nasa.gov/catalog/PIA09202<br />ok, not really digging arm as such but it should be able to do quite a lot of rock sampling. <br /><br />oh, here is a nice video of MSL landing sequence:<br />http://youtube.com/watch?v=E37Ss9Tm36c

 

[3488]

Yes, as you say no_way, it appears to be laike the RAT & microscopic imager as on the MERs, rather than as a trenching arm as on Viking 1 & Viking 2.<br /><br />The arm that MSL will have will be much less energy intensive, as it will not ' dig & lift' soil as the Viking landers did.<br /><br /><font color="red">I took this from the Planetary Photojournal:</font><br /><font color="yellow"> Original Caption Released with Image: <br />VIKING LANDER DIGS A DEEP HOLE ON MARS -- This six-inch-deep, 12- inch-wide, 29-inch-long hole was dug Feb. 12 and 14 by Viking Lander 1 as the first sequence in an attempt to reach a foot beneath the surface of the red planet. The activity is in the same area where Lander 1 acquired its first soil samples last July. The trench was dug by repeatedly backhoeing in a left-right-center pattern. The backhoe teeth produced the small parallel ridges at the far end of the trench (upper left). The larger ridges running the length of the trench are material left behind during the backhoe operation. What appears to be small rocks along the ridges and in the soil at the near end of the trench are really small dirt clods. The clods and the steepness of the trench walls indicate the material is cohesive and behaves something like ordinary flour. After a later sequence, to be performed March 1 and 2, a soil sample will be taken from the bottom of the trench for inorganic soil analysis and later for biology analysis. Information about the soil taken from the bottom of the trench may help explain the weathering process on Mars and may help resolve the dilemma created by Viking findings that first suggest but then cast doubt on the possibility of life in the Martian soil. The trench shown here is a result of one of the most complex command sequences yet performed by the lander. Viking l has been operating at Chryse Planitia on Mars since it landed July 20, 1976. </font><br /><br />The image below is from Viking 1 in Chryse Planiti <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[3488]

Viking 2 digging.<br /><br /><font color="red">I took this from the Planetary Photojournal:</font><br /><font color="yellow"> Original Caption Released with Image: <br />Operation of the surface sampler in obtaining Martian soil for Viking 2's molecular analysis experiment last Saturday (September 25) was closely monitored by one of the Lander cameras because of the precision required in trenching the small area--8 by 9 inches-surrounded by rocks. Dubbed 'Bonneville Salt Flats,' the exposure of thin crust appeared unique in contrast with surrounding materials and became a prime target for organic analysis in spite of potential hazards. Large rock in foreground is 8 inches high. At left, the sampler scoop has touched the surface, missing the rock at upper left by a comfortable 6 inches, and the backhoe has penetrated the surface about one-half inch. The scoop was then pulled back to sample the desired point and (second photo) the backhoe furrowed the surface pulling a piece of thin crust toward the spacecraft. The initial touchdown and retraction sequence was used to avoid a collision between a rock in the shadow of the arm and a plate joining the arm and scoop. The rock was cleared by 2 to 3 inches. The third picture was taken 8 minutes after the scoop touched the surface and shows that the collector head has acquired a quantity of soil. With surface sampler withdrawn (right), the foot-long trench is seen between the rocks. The trench is three inches wide and about 1 1/2 to 2 inches deep. The scoop reached to within 3 inches of the rock at far end of trench. Penetration appears to have left a cavernous opening roofed by the crust and only about one inch of undisturbed crust separates the deformed surface and the rock. </font><br /><br />The image below is from Viking 2 in Utopia Planitia.<br /><br />High resolution here: Trenching in Utopia Planitia.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[brandbll]

Question: Why not send some small impact probes along with the rover, that crash near the landing site? Then you don't have to worry about digging. <br /><br />Also, i realize teh accuracy of said impacts wouldn't be very good, but atleast that way you don't risk teh chance of messing up the rover. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[no_way]

the rocket-powered part of MSL lander IS actually going to crash approximately 100 meters away from the rover drop off site. It probably wont make much of an impact and crater however, as its hovering height is around 10 meters or so.

 

[jimfromnsf]

MSL will avoid the impact area of the descent stage so as not to get contaminated by residual fuel and other materials.

 

[brandbll]

Which is exactly why they need some impact probes. I don't know why people didn't think of this earlier. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[centsworth_II]

The extra weight of impact probes would either require a larger<br />craft, or a severe reduction in science gear. No buget for the former, <br />no stomach for the latter. I'll take long-lived, rover based science<br />equipment over dead weight impact probes. A drill or digger would<br />be the way to go for subsurface investigations.<br /> <div class="Discussion_UserSignature"> </div>

 

[brandbll]

Or, just send a basic rocket loaded with the suckers and when it gets there have it release them like a shotgun shell. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[centsworth_II]

"Just"?<br />I think a "basic rocket" to Mars would be quite expensive.<br /> <div class="Discussion_UserSignature"> </div>

 

[brandbll]

Well it's certainly not going to make it there if your trying to send it on your <b>half empty</b> tank of fuel. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>but it looks as if power budgets, have to trade trenching OR roving<p><hr /></p></p></blockquote>If we park to dig, wouldn't that free up the power needed by the wheel motors? <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

Mars Polar Lander included Deep Space 2 which was two impacters. Neither reported back. I have to believe that they never seperated from the cruise stage as neither MPL nor the DS2 probes could phone home until they reached the surface. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[jimfromnsf]

More than likely they did separate, pryo systems are very reliable

 

[3488]

Very likely they did, but owing to the nature that,<br />absolutley nothing was heard from Mars Polar Lander & the penetrators, <br />does lend credibility to the theory that the probes did not seperate from the Cruise Stage<br />just prior to Martian atmospheric entry.<br /><br />IMO, this was not the cause of the failure, but cannot<br />be ruled out.<br /><br />The official line is that, when Mars Polar Lander's heat shield was jettisoned, the landing legs open normally,<br />but this caused a conflict in dodgy software.<br /><br />When the parachute was jettisoned & the braking motors kicked in,<br />the onboard computer, reckoned that the landing had taken place, the motors cut off, & <br />the lander fell about 40 metres to its destruction.<br /><br />Even under 38% gravity, that is still quite a drop.<br /><br />MRO is due to use the HiRISE this month to continue the search that <br />MGS started, looking for evidence of what went wrong.<br /><br />With Mars Phoenix Lander, hopefully these lessons,<br />have been learnt & also that the landing of MSL has not been made too complicated.<br /><br />There is much to be said for airbag landings, that Mars Pathfinder, MER A Spirit & MER B Opportunity<br />used so successfully.<br /><br />Andrew Brown.<br /> <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[willpittenger]

The pryos might well have gone off -- and yet the parts might still have not separated. All it would take is something hanging up on something else. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[jimfromnsf]

A marmon clamp is not going to hang up on something much less two

 

[3488]

Well what ever happened (hopefully the MRO will image the area very soon with HiRISE), Mars Polar Lander<br /> was launched with insufficient testing, with a very tight budget.<br /><br />I do think that lessons have been learnt in this respect, but<br />would be far happier if both Mars Phoenix Lander & MSL were using airbags, although MSL is maybe too heavy!!!<br /><br />The landing for MSL appears far too complicated & I am not sure that it will land successfully.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>