Talk:PrOP-M/GA1

GA Review
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Reviewer: RoySmith (talk · contribs) 13:43, 15 January 2022 (UTC)

Hi, I'm going to review this article. It looks like a fascinating topic, and I have no problem with the article being short if there's really nothing else that's available. But, before I dive into the review, could you please take a look at the following sources which you seem to have missed and see if there's anything else you can find that's relevant:

I also found this in ProQuest:
 * Gunn, M. D., & Cousins, C. R. (2016). Mars surface context cameras past, present, and future. Earth and Space Science, 3(4), 144-162. doi:http://dx.doi.org/10.1002/2016EA000166

This is the kind of topic where there should be lots of material in the scientific literature, for which you'll have to dig into the databases like ProQuest and JSTOR. Free subscriptions to both of those are available to all wikipedia editors. See WP:LIBRARY for details.

Also, look at ru:Прибор оценки проходимости — Марс. Even just using the machine translation, I found a few interesting facts such as the location in Ptolemy crater. I see there's articles on uk and bg as well, which are worth taking a look at for the same reason. The uk article says that the densitometer was sensitive to gamma rays and that it could move 1 meter/hour. The wiki articles aren't WP:RS, but should give you some suggestions for additional searching.

Hi, thanks for taking this review!

About the sources: here are everything from all the books you found:

"'The lander was a roughly spherical structure with four segmented “petals” which opened to self-right the lander and expose the instruments, plus a tethered rover; “Prop-M” [Perminov, 1999]. In addition to the two cycloramic cameras, the lander carried a mass spectrometer, atmospheric sensors (temperature, pressure, and wind), and other instruments to determine the mechanical properties of the Martian surface [Johnson, 1979; Perminov, 1999].'"
 * in Mars surface context cameras past, present, and future:

"During the same time frame, in 1971, the Soviet Union sent two spacecraft landers to planet Mars as missions called Mars 2 and Mars 3 (Fig. 1.5). Both of the Mars 2 and Mars 3 landers carried a small Mars rover (PrOP-M) on board (mass of 4 kg, ~20 cm in largest dimension), which was designed to move across the surface while connected to the lander via a 15-m power and communications tether. The mobility system, comprised of ski-like mechanisms, would enable locomotion in a sort of slow ski-walking manner (at up to 1 m/h). To enable measurement and evaluation of terrain properties near its lander, the rovers had both a densitometer and a dynamic penetrometer for testing the density and bearing strength of the soil. The intelligence embodied in the PrOP-M rovers was limited to tactile sensor-based autonomous obstacle detection (by contact) and avoidance. These rovers would have used these features to explore the area within 15 m of the lander, however, neither PrOP-M rover got the chance. The Mars 2 lander unfortunately crashed during descent to the Martian surface, and the Mars 3 lander suffered permanent loss of communications within one minute of safely landing on Mars."
 * in Robot Memetics:

"The Prop-M rovers were small Soviet rover platforms launched with the twin mission Mars-2 and Mars-3, 9 days apart. Though the orbiter segments were successful, both the Mars-2 lander (with a planned landing on November 27, 1971) and Mars-3 lander (that landed on December 2, 1971) were unsuccessful. The Mars-2 lander failed during entry, descent, and landing (EDL), and Mars-3 only provided 14.5 s of data after landing. The 4.5 kg platforms were about 215 × 160 × 60 mm (as illustrated in Figure 2.12) and tethered to the lander to provide power and data links. It would have allowed the rover to traverse about 15 m from the lander and gather science data every 1.5 m. The payload suite was comprised of a dynamic penetrometer and a radiation densitometer to measure soil density. The rover was deployed from the lander to the surface by means of an articulated deployment mechanism as illustrated in Figure 2.13-top. The Prop-M platform provided a new paradigm for surface mobility, implementing the first nonwheeled vehicle for planetary applications. Built with two rotating skis, the rover provided a forward motion by pivoting its skis through rotating lever arms connected to its body. It placed on the surface alternatively its skis and its body to provide a forward motion. Rotation was performed through skid steering by moving one ski forward and one ski backward [30]. A simple autonomous behavior of the rover was implemented to allow the platform to avoid obstacles during its traverse. If the tactile collision sensor in front of the vehicle detected an obstacle, it initiated a sequence where it moved one step backward, turned slightly, and moved forward again as illustrated in Figure 2.13."
 * In Contemporary Robotics:

"'It was also announced that data from the landers was to assist in the development of the future 'Planetokhods', or planetary rovers?; This statement assumed a new meaning when the Russians revealed in the early 1990s that each dander carried an amazing experiment — a 4-kg mini-rover equipped to measure soil properties. This had been designed and built in just 18 months by the institute of mobile vehicle engineering VNII Transmash of Leningrad, which had already designed Lunokhods for use on the Moon. It was named PrOP-M (Pribori Otchenki Prokhodimosti-Mars, instrument for cross-country characteristics evaluation on Mars), 'Marso-khodik' or 'Micromarsokhod' (small Martian walker). After a 6-fold boom had placed it on the ground, the 21.5 x 16 x 6-cm box-shaped robot was to use skids in a parallelogram configuration to walk at a speed of 1 meter per minute out to a maximum of 15 meters from the lander, its range being limited by the umbilical that would supply power (it used just I W), commands and telemetry. On the front was a bumper with two levers that worked as an obstacle sensor. The rudimentary artificial intelligence of the robot was to enable it to identify the position of the obstacle, and then take several steps backward and attempt to walk around it, steering by moving the skids in opposite directions. It was to halt every 1.5 meters to undertake soil-mechanics measurements using its two instruments: one a penetrometer supplied by Transmash, and the other a densitometer provided by the Institute of Geochemistry of the Soviet Academy of Sciences. More data was to be gleaned from analysis of the pictures of the traces left in the soil by excrescences of various sizes imprinted on the underside of the vehicle. The Soviets planned to use the data obtained to design the locomotion system for more sophisticated Mars rovers. This approach was the same as that used for lunar missions, in which data collected by the penetrometer and densitometer of the Luna 13 dander in 1966 was exploited in the design of the Lunokhod rovers of the 1970s.'"
 * Ulivi in Robotic Exploration p 105:

"All planetary rover missions to date have adopted wheeled chassis designs across a range of rover sizes for mechanical simplicity and high reliability. This trend looks set to continue for the foreseeable future. One exception was the Prop-M nanorover on the Russian Mars 3 lander (1971). The 4.5 kg Prop-M used a pair of skis mounted onto legs. Regrettably, the mission failed after apparently landing successfully.'"
 * In Planetary Rovers Robotic Exploration of the Solar System by Alex Ellery, p 59:

"The 4.5 kg PrOP-M rover was a box 250 x 250 x 40 mm with a small protrusion rising from the center of its upper surface. The body \Vas supported by two skis. one projecting dov,m from each side. By moving the skis in alternating fashion the rover was able to walk', and by moving them in opposite directions it could turn. There vvere obstacle-sensing bars at the front, and it was programmed to reverse in order to circumnavigate an obstacle. The rover was to be deployed by a 6-joint manipulator ann and moved into the field of vie\v of the cameras. It was tethered by a 15 meter long cable for direct communication vvith the lander. and was to pause at intervals of 1.5 meters to make measurements. It carried a dynamic penetrometer and a gammaray densitometer, and its tracks were to be photographed to investigate the physical properties of the surface. "
 * In Soviet Robots in the Solar System p 256:

At the simplest end of the spectrum of complexity are relatively ‘dumb’ instrument-deployment devices, whose function is to transport sensors from a lander across the planetary surface beyond the radius accessible from the lander itself (e.g. by robotic arm). Such devices are usually tethered to the lander to provide power and data connections, which limits mobility but does minimize the need for power and communications equipment and autonomous control on the rover. The first such device flown was the PROP-M tethered walking rover flown on the Mars 2, 3, 6 and 7 landers in 1971 and 1973. All four missions were lost before PROP-M was to operate, however. Deployed by an arm from the lander, PROP-M was to perform penetrometry and densitometry measurements on the Martian surface material. It had the capability to sense (by means of ‘whiskers’ at the front) the presence of an obstacle, step backwards and turn to move around it.
 * In Planetary Landers and Entry Probes, p 127:

" The landers carried a small walking robot or skid rover, called PROP-M Pribori Otchenki Prokhodimosti-Mars (literally "instrument for evaluating cross-country movement") with a mass of 4.5 kg and tethered to the craft for communications. The skid rover was a squat box 250 x 200 x 40 mm, with a dynamic penetrometer and radiation densitometer, designed to walk on skids up to 15 m, the limit of the cable. It was programmed to stop to make measurements every 1.5 m. The skid rover had built-in artificial intelligence: when it met an obstacle, it was programmed to reverse and use the skids on alternating sides to walk around the obstacle. "
 * In Russian Space Probs:

It's the same info with the same photo in all these books. I could use some of them as sources, that may be preferable to my current ones. The only difference is that some books give different numbers for the dimensions of the rovers.

About the Russian wiki article: location in Ptolemy crater is probably were the lander crashed, but rover wasn't deployed. I can add it, if you think it's needed. I would also add about gamma-rays, but I see no RS for rover's speed of 1 meter per hour. I would also quote Ulivi, his book seems to be the best source of all. Artem.G (talk) 17:40, 15 January 2022 (UTC)


 * @Artem.G OK, thanks. I suspect everything traces back to some small set of original primary sources and all the rest just keep copying from each other, so that's fine.  I had noticed the discrepancy in the dimensions.  Since we've got sources that disagree with each other, I'd certainly mention that rather than just blindly endorsing one set of numbers.  Something along the line of "Sources differ on the physical size of the rover.  Some say it's X1 x Y1 x Z1, others say X2 x Y2 x Z2" works, with a citation to the best source you can find for each set.  I'll take a deeper dive into this when I get a chance. -- RoySmith (talk) 18:02, 15 January 2022 (UTC)

Images
I'm going to start here because I think there may be a problem meeting WP:NFCC.

File:Mars propm rover.jpg asserts that the image is PD because it was "solely created by NASA". But, all that's given as the source is the deep-link URL for the jpg file, not a link to a page on NASA's web site which explains the provenance of the image. At a minimum, this needs better attribution to confirm the copyright status. Note the licensing template that says, The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.. I suspect that applies here.

I'm also worried about File:PrOP-M on the manipulator.jpg. The source is a page on the IEEE web site, but it gives no information about where the image originally came from. That probably fails WP:RS, but more importantly, it can't meet WP:NFCC's Identification of the source of the original copyrighted material requirement. Also, the image is of such poor quality, it's not clear that its presence would significantly increase readers' understanding of the article topic, and its omission would be detrimental to that understanding.
 * working on it.

Lede
For an article this short, I would make the lede a single paragraph. I'd leave out the details of why the Mars-2/3 missions failed (crash landed, lost comm) and just say that the missions were failures. Maybe just, "...that were launched on the unsuccessful Mars 2 and Mars 3 missions in 1971"
 * done

Don't mix tenses: "they were small ... that were tethered ... and would have used". Change "would have used" to "used".
 * done

Infobox
Why "dry mass"? I think that's usually used for spacecraft to indicate the mass without propellant, but as far as I can tell, this didn't carry any propellent, so just "mass" would make more sense.
 * removed, you are right. The mass is given in the body.

History
"who is known for developing" --> "who also developed"
 * done

"Both Mars 2 and Mars 3 landers had a PrOP-M rover" I think would read better as "The Mars 2 and Mars 3 landers each carried a PrOP-M rover".
 * done

"Which would have...", again, the change of tense is jarring. I get that they didn't actually move because they never actually worked, but how about, "designed to move..."
 * done

"cameras' fields of view". Is that intentionally plural? Were there multiple cameras? Were the camera(s) on the lander or on the rover?
 * rephrased. The were several cameras on the lander.

"The rovers' main rover frame" is awkward. Perhaps "The rovers' main chassis"? Also, my note earlier about differing sources.
 * done

"27 November 1971" Be consistent about dates. Here you use DMY. In other places, you use MDY.
 * done

"...before the first successful NASA's rover". Maybe, "...before NASA's first successful rover, Soourner"? But that implies that NASA had an earlier rover, which was not successful. Is that accurate?
 * rephrased. No, Sojourner was first NASA's rover, and it was successful.

Missions
Could this list be turned into running prose, per MOS:EMBED?
 * done, removed.