Updated 2017-03-10


All teams are highly encouraged to submit abstracts for and present at the Annual Mars Society Convention. Teams who present have the opportunity to submit full papers to be published by the Mars Society’s MarsPapers.  Teams are also highly encouraged to submit papers to any other journals or conferences. 


Competition Questions

[1.Q] Can teams ask questions?
 [1.A] Yes. All questions and answers are added to the Q&A. See the contact page if you have any questions. 

[2.Q] Are there videos of rovers or astronauts completing the tasks?
 [2.A] The judges do not plan on making videos of the updated tasks or the infrastructure. However, many videos of past competitions are available online. These are a good source of information on how previous teams have designed, built, and operated their rovers.

[3.Q] Will there be any help with visa procedures for international teams?
 [3.A] There is no direct assistance with the visa process, although URC will provide a letter of support upon request. Early application is advised for as many team members as possible. We strongly suggest not waiting until after the critical design review. In recent years some international teams have had difficulties obtaining enough visas to field an adequate team.

[4.Q] Different regions pay different taxes which puts regions with higher taxes at a financial disadvantage, with respect to the $15,000 budget cap. [4.A]  These are just some of many region-specific pricing factors such as raw materials, labor costs, and exchange rates. Few teams get close to fielding a $15000 rover and we will review the budget rules if in future they do appear to become an important factor in the success of teams at URC.

[5.Q] Rule 1.i.i. says that volunteer labor does not need to be included in the $15K budget. If a company volunteers to machine components for us, or cuts custom PCBs we designed, do we only need to include the cost of the raw materials?
 [5.A] We would consider this donated labor not volunteer labor.  See rule 1.i.ii. If the company gives you free access to their machines, or you purchase your own machining equipment, and you do the machining yourselves, then you only need include the value of the raw materials.

[6.Q] Rule 1.i.v. says that if a part is purchased commercially the "as-bought" price may be used. Does that mean that if we buy a component at a discount, we only need record the price we paid for it?
 [6.A] If you buy something new or used, at a discount or not, you can use the price you bought it at, provided that it is not a special price just for your team.  I.e. if someone not on your team can buy it at the same price then it is a fair market price and you can use that price. Conversely if the seller is only offering it at that price to your team, then the price you are getting is below market price, and the difference is essentially a donation, so you need to report in your budget the price the seller would have sold it to someone else for.  

[7.Q] Can we set up a 12'x12' canopy for our team between events?
 [7.A] Yes, you may set up a tent as you please but be warned that we switched from tents to trailers due to problems with high winds at MDRS.  If you wish to work on your rover, we do not allow testing at the field sites during the competition due to potential radio interference. You can only test your rover off-road on the state lands. (See link to map in section 1.g. of the rules).  You can only drive on the designated roads which makes staying in the state lands and away from the competition sites difficult. You will however be more than welcome to do all the testing you like either on the dirt roads away from the competition or back in Hanksville.

[8.Q] How much time is there between events to modify our rover in?
 Can we modify a rover during a task? When will we know our schedule? Is there a set order of the tasks? [8.A]  Between each task you may modify the rover as you wish. During a task you may have an intervention at a 20% penalty, where the aim is to allow you to fix a broken rover if you need to, not to swap out modular components.  For scheduling see rule 3.a.i. and between tasks you make any modifications you choose. You will be given your exact schedule on the first day of the field competition. We can't specify in advance of that since we won't know teams' communications frequencies/protocols until shortly before the competition and we schedule teams to minimize potential interference. The order of tasks will be different for each team and is the luck of the draw.

[9.Q] We see that teams are rewarded 100 points for the CDR. Will there still be a Presentation task as in 2016?  [9.A]  The Presentation Task due immediately before the competition been eliminated for 2017.  The CDR will now count towards teams' scores in its place.

[10.Q] Does the antenna stand itself, all steering hardware, and such all count towards the budget?   [10.A]  Yes, all communications items outside the control station count towards the budget, but not the weight limit. Other equipment such as cameras, relays, sub-rovers, etc, would need to be deployed by the rover and will count towards the weight limit as well as the budget.

[10.Q] Does the cost of spare parts have to be included into the $15,000 limit for the rover?  Similarly, how do spare parts apply towards mass limits?   [10.A]  For the purposes of this question, there are two categories of spare parts.  Spare parts that are replaced one-for-one, and only in the case of damage to the original, are not counted against the budget or mass limits (e.g. if a motor controller burns out, it can be replaced without taking a budget/mass penalty).  Conversely, any spare parts that are fielded on the rover that add additional capability must be accounted for in the team's budget, and fit within the budget cap and mass limit.  Teams whose initial budget submissions are above $14,500 should take extra precaution with accounting for spare parts fielded during the competition.

[11.Q] We are considering renting some equipment for the science cache task. Can we just use the rental cost in the budget? [11.A] It depends on whether the equipment will be fielded on the rover, or just used for the laboratory analysis. Cost limits only apply to the rover and communication equipment (see rule 1.i.i. and Science Q&A 14). There are no budget or mass limits on the laboratory analysis. On the other hand, equipment fielded on the rover should be valued at full cost, not just the rental cost but you may use the cost of a second hand one if you can find one for sale and document that cost.

[12.Q] During competition will teams have any ability to police judges and spectators so they don't interfere with the task such as by obscuring the rovers vision of the markers in the autonomous traversal task? Can we expect a clear 360 degree field of view? [12.A] No. It the the judge's job to make sure the competition is fair and that spectators are not interfering with the competition either against, or more commonly to unfairly aid the team (such as pointing out the location of objects). The usual rule is that judges and spectators need to do their best to stay behind the rover at all times, or at least not in the forward 180 degree field of view. If you have concerns during the competition please bring it up with the URC director. You should expect 1-2 judges to be following the rover for scoring purposes. You are unlikely to have any spectators other than your own team members, and if there are others it should be by your permission. It is your prerogative to request no-one other than the judges follow the rover, although most teams send at least 1-2 people to act as runners should the need arise.


Rover Questions

[1.Q] Is a magnetometer allowed for navigation? We designed our navigation system using a magnetometer, then realized the magnetic field on Mars is not sufficient to use on an actual Mars Rover. [1.A] Even though they are not analogous to operations on Mars, it would be difficult for us to verify that teams aren't using a digital compass or magnetometer.  Since it's only a coarse backup navigation, passive magnetometers will be allowed.

[2.Q] We would like to deploy a communications module from the rover. We were wondering whether we would have to retrieve the module with the rover before the end of a task, or if we could just leave it there? [2.A] As in rule 1.b.i anything deployed by the rover should be collected before returning to the start gate. If deployed objects are not collected you will forfeit the points for returning the rover to the start gate on time. This is usually only a small number of points (although usually easy to earn), so you will have to weigh the increased potential for completing a task against the risk of not being able to collect the objects you deploy.

[3.Q] Would the rover be allowed to pull another across the starting gate as a sort of trailer behind the rover? The two vehicles would be "tethered" to each other, but not to any external sources. Also, would this apparatus be considered a "single connected platform" as stated in Section 1.b.? [3.A] The tether in rules 1.b. and 2.c. refers to power and control between the deployed system(s) and the command station.  There is no restriction on tethers for power/control between subsystems deployed by the rover.  A system that has physical coupling via a tow-rope will be permitted as a single connected platform.

[4.Q] Can we bring a UAV (Unmanned Aerial Vehicle a.k.a. drone) to URC?  [4.A] No. Unfortunately due to increased FAA restrictions we can no longer fly airborne vehicles at the URC sites near the Mars Desert Research Station due to the proximity with the uncontrolled Hanksville airport. We are hoping to bring UAVs back in the near future with a specific UAV task at a location further from the airport, or possibly in an entirely separate competition. Stay tuned if this is of interest to your team.

[5.Q]  Can we include a microphone on the rover? Listening to rover's sounds, not just relying on sensor data, during tasks is great help for operator to determine if everything is working correctly. [5.A] Yes, microphones are permitted on board the rover.  However, teams will need to notify the judges prior to each task in which microphones are being used.  As in rule 1.d team members are not allowed to provide feedback to the operators and should take care not to do so. Judges will then monitor conversations that occur near the rover by both judges and spectators to ensure that no unintended information is provided to the team in the control station.

[6.Q] Regarding rule 2.b. what are the penalties for exceeding the 70 kg total limit or are there only penalties for exceeding the 50 kg single configuration limit? Are there penalties for exceeding the $15K cost limit? [6.A] The 70 kg total mass and $15K are strict limits. In a real space program you will typically be given a strict weight limit and probably size and budget limits too, and short of exceptional circumstances will be expected to stick to it. To be most realistic and fairest to all teams the 70 kg weight and $15K budget will be enforced as strict limits. If you rover weighs in over 70 kg you will have to discard parts, drill holes, or whatever it takes until your rover is under the limit. 

[7.Q] Is it permissible to utilize a satellite internet provider, such as Exede or HughesNet, in order to achieve a data connection with the robot? [7.A] Not for the 2017 competition, but will consider changing this for 2018 if there is enough interest. While we do grant GPS, we currently consider use of a satellite relay to be not quite in the spirit of the competition. However, there are plenty of ways to set up a local transponder in the field which we strongly encourage. In general we do not like saying no to specific technologies, but to date the Mars Society has not found satellite relays to be a reliable communication link for real-time operations. We want to keep the competition fair,  and don't want to subject teams to trying it just yet, but are open to persuasion in future. 

[8.Q] We have amateur radio operator licenses and would like to use 2.4GHz band with high power, but high power is only allowed in the range 2.39-2.45 GHz (channels 1-6). Would we be permitted to only use channels 1-6? [8.A] During competition you will likely be randomly assigned 2.4GHz channels 1-3, 5-7, or 9-11 based on whichever control station is available when you arrive. You would be OK using licensed high power on channels 1-3 or 5-6 but would have to drop back to unlicensed power limits on channels 7 and 9-11. We will not guarantee channels ahead because it would make scheduling a nightmare. The URC controls on the 2.4 GHz band are very rigid to ensure that one of the most frequently used bands is well regulated, interference free, and predictable for all teams. If you want to use licensed high power operation you should consider using the amateur bands outside of the URC controlled 2.4GHz wifi and 900 MHz RC bands. There are plenty to chose from if you have a license. 

[9.Q] We have a 2.4GHz transceiver we'd like to use that is frequency hopping and can be confined to bandwidth 28MHz centered on what would be channels 1.5, 7, and 12.5. Is this in violation of the rules? If not, do you know of any 2.4GHz or 900MHz frequency hopping transmitters that are compliant?  [9.A] This is an interesting transceiver we may use to explore modifications to the rules in future, but for now is not permitted as described. The rules are very rigid in the 2.4GHz band to make it predictable and interference free for all teams. Since we cannot guarantee teams operating in neighboring channels won't experience interference or offer similar flexibility to all teams we must disallow this transceiver. We do not provide guidance or recommendations on specific products since sourcing parts is a critical aspect of the design and build process. However, many teams are very open and collaborative so suggest you post a message on the URC Social Hub (www.urchub.com) or the URC Facebook page. We strongly encourage experimentation and customization of radio equipment, but the 2.4GHz wifi and 900 MHz RC channels are probably not the best bands to do that on. We suggest you consider the 5GHz band, which is much less popular, has many more bands, is not regulated at URC,  and where extreme broadband spread-spectrum is standard on many off-the-shelf transmitters. You can also get an amateur radio operator license which will open up many more bands and you can build any kind of modulation, spectrum spread, interference tolerant system you can dream up. 

[10.Q] Are there any limitations on using lasers[10.A] We have no rules on the use of lasers. As with everything else you should comply with normal health and safety rules and guidelines. A low power laser pointer or rangefinder is likely reasonably safe but for an extra step you may want to add a large warning label and automatically shut it off if pointed above the horizontal, so people know it is there and it is not accidentally pointed in anyone's eye. With any potential hazards, think it through, consult an expert, and take appropriate caution. You are a lot more likely to hurt one of your own team during testing.

[11.Q] We have a unique controller for the arm. Does this count as communications equipment that needs to be included in the budget, or command equipment that does not[11.A] Rule 1.i.i only covers the transceiver, antenna, and supporting hardware, so your arm controller does not need to be included in the budget. We look forward to seeing what you come up with.


Science Cache Task Questions

[1.Q] Rule 3.b.ii asks for a panorama with cardinal directions on the picture and some indication of scale. Scaling a panorama of an entire horizon is not really useful because in the stitching process of combining pictures, the ranges are often distorted so that the image can fit the entire horizon. 
 [1.A] The intent is to provide context of the sample location with respect to the local geography and other features of interest. The wide-angle panorama is not required to be a 360 degree horizon image, and can be a single wide-angle shot or stitched as teams see fit.  The requested scale indication should be applicable to the sample region, and does not need to be perfectly precise, but merely provide an order-of-magnitude level of spatial awareness, since in the desert, without a known size reference, 100 meter features can easily appear to be close up shots of 10 meter features.

[2.Q] For the indication of scale in the panoramic photo, Is a ruler or prop of known dimensions placed by the rover in the field of view satisfactory for this requirement? Is the viewing angle of the camera sufficient?  [2.A] The camera viewing angle alone gives no information on distance or size of objects so is not sufficient. Yes, a ruler can be used as a scale. It doesn't matter what you use as scale, as long as you can give us the scale and it is contained within the Rover package.  You would need to deploy any rulers from the rover and will have to decide if this or alternative methods are the best way to indicate scale.

[3.Q] What resolution do you consider as high resolution in rule 3.b.iii?
 [3.A] This is up to you. Convince us that whatever resolution you pick provides meaningful scientific information on the location.

[4.Q] What is meant by stratigraphic profile? Is this an above the surface picture of layers such as those that can be seen in a hill or is it a below the surface picture of layers such as those that could be seen in a core sample?  [4.A] A stratigraphic profile is vertically layered deposits. There will be an exposed cliff side at the competition site for you to profile. No digging or drilling to obtain a profile will be required. Similar to the rovers on Mars, the size, position, aspect, location or any other information about the stratigraphic profile will not be provided prior to the competition.  We expect that part of your pre-competition science research will include learning about stratigraphic profiling and especially examples of what to expect at the competition area in Utah and also on Mars prior to aid in the science task.

[5.Q] In 3.b.iv, what is considered sealed for the sample storage container? Does it have to be water tight or just covered? What is considered to be a "cache container"?
 [5.A] The on-board sample storage container is the "cache container": they are the same thing. We expect the teams to do some research into methods for microbial sample collection. Cache for this competition is based on the current Mars sample return strategy as mentioned in the latest Planetary Science Decadal survey: Vision and Voyages (boxes C.3 and C.4 and in the shorter summary version page 21). In this context we expect teams to do some research as the requirements that will be needed to reach the "cache goal". For this competition the cache goal is to store a sample for later analysis, which means the teams need to decide and defend their cache choice in achieving the objectives.  In short, we expect a microbial clean container, so yes, air and water tight.  We also expect the teams to have a way to keep their container free of contamination from the human microbes when handing the judges the container. As a HINT:  A urine sample container is sterile and will hold the appropriate amount of soil/ rock.

[6.Q] We are assuming that the "Martian" atmosphere during the competition is microbe-free and the sample needs to be protected only to avoid contamination once it gets back to the "habitat" where humans reside. Can we assume that in a real mission a clean room would be available and any tasks that could expose the sample to airborne microbes would be done there?
 [6.A] No, those assumptions are incorrect. The Cache container needs to be clean and the sample needs to be kept clean/ contamination free from collection into the cache container. We are concerned about the possible contamination of the cache from the cache itself and the rover, as well as the human team members. 



[7.Q] Do we need to collect the sample without exposing it to the atmosphere at all, or can it be exposed to air once removed from the ground or can we scrape off the ground surface to expose an area to collect a sample from?
 [7.A]  Exposure to the atmosphere during collection is considered acceptable. Part of the task is to figure out what the cache is, by looking at the NASA Mars 2020 website for example. The most important parts are the transfer from collection to cache container, and providing a sealed cache to the judges. We don't want parts of the rover in with the sample or microbes from the team members in the cache.

[8.Q] Is the soil composition going to be such that we would be able to just scoop it up, or is it going to be compacted enough that we would need a drill? Will there be any indication of where to perform the soil tests? [8.A] There are many different types of soil and rock conditions at MDRS. There is no specific guidance on the specific sample types that teams should be prepared for (i.e. hard rock vs. soft soil). This is left as a design decision for each team. 
Judges will be providing general descriptions of the task site, but otherwise, no markers will be provided.

[9.Q] Are we allowed to carry a sample from one site and dump it later if we find a better sample at another site? Will teams be allowed to chip or drill pieces of the rock away? Is flipping over rocks, or removing a rock and then returning it to its original location, considered invasive? [9.A] Yes, teams may discard samples. Keep in mind that many teams will be investigating the same sample sites, so rovers should avoid causing major changes that will impact other competitors (including leaving excessively large holes, and causing significant disturbance to the soil). In general, physically manipulating a rock for closer inspection is not considered to be invasive as long as it is done with discretion, targeting specific samples. As a general rule of thumb, teams should design their systems to take only the amount of soil needed to perform a given test, and minimize visual disturbance. Deposition of chemicals or water onto the course is not permitted.

[10.Q] If the same tool is used to collect multiple samples, will teams have to account for contamination (e.g. if there was life teams wouldn't be able to say definitively that it came from Sample B since the tool also touched Sample A).
[10.A] As with all scientific analysis, teams must seek to minimize possible sources of contamination, yet understand and disclose possible sources when they do exist.

[11.Q] How many samples do we need to return, or is one enough? [11.A] Teams will be judged on the quality of the science of the site and sample analysis and the ability to explain why they chose a sample, not on the number of samples. An in depth description of one sample collected is better than a poor explanation of five samples collected.

[12.Q] For the additional onboard science capability of the team’s choice, is that just any instrument that can analyze the site? For example, would a spectrometer or microscope count for this or is URC looking for something more elaborate/a wet chemistry experiment? [12.A] Onboard equipment must at least contain soil humidity and subsurface temperature tests. Any additional instrument that produces data to enable useful scientific analysis is sufficient, including a spectrometer or a microscope.  The cost and complexity of the instruments are not as important as a thoughtful plan for the field work, and quality of analysis based on data returned.

[13.Q] Detailed spectral analysis is an option that increases the budget of the rover to a level that may not be feasible. Otherwise our only option is to purchase an inexpensive digital microscope and try to image the bacteria with that. However, to find naturally occurring cyanobacteria with this method would be nearly impossible. Are judges going to seed the sites with additional bacteria, so the population density is greater? [13.A] The objective of this task is not to find conclusive proof of cyanobacteria or other life form, but to build the case that a particular site is or was suitable for life. Regarding the cost of various tools and sensors, this is one of many trade-offs that teams are required to make as part of their design process. Part of the judges' decision will also focus on how well teams have used the tools that they do have, and how well they interpreted the data returned to make an educated analysis. The judges will ensure that this task is feasible in terms of finding sufficient opportunities for data collection.

[14.Q] Is any equipment provided for the bench analysis, or will we have to provide everything we wish to use? Is there any restriction for number of instruments/weight?
 [14.A]  The only equipment provided will be a digital scale to weigh the sample. No other science instruments are provided for the laboratory analysis. US mains power (110-125V, 60Hz) will be available to power anything you bring. You will need to provide everything else you need. There are no restrictions (mass or budget) on the equipment that may be used in laboratory analysis. However, the primary intent of this analysis should be to confirm analysis performed with the rover and to support the justification made when selecting the sample for return. Points will be awarded not by the size and extensiveness of a team's laboratory, but rather based on how well teams are able to relate their analysis to the work performed with the rover. The main idea is to judge the performance of the rover in performing the in-situ investigation.

[15.Q] What is the extent of the devices allowed at the base station? For example, say a team wanted to do seismic testing and imaging, which required a 'thumper' unit at the base station that vibrated the soil? [15.A] For operation in conjunction with the rover would be included in the 50kg weight limit so is probably not a good use of weight allocation. Also, the science task is geared towards biology and the search for life so the thumper is not recommended. For the post-traverse laboratory analysis, this will probably be conducted back in Hanksville, where the only limitations are:  No harmful chemicals or reagents without prior approval (rule 3.b.vi), and the the feasibility in the time it takes to get everything set-up (base station) and rover in the limited set-up time. 

[16.Q]
For the third onboard sensor, does it need to be completely onboard or can we transmit the output to the command station such as via a video feed for interpretation by a human
? [16.A] Yes, you may use a video feed to monitor a sensor. You must be able to see the results while the rover is exploring the site, not have to wait until the rover physically brings the samples and tests results back to the command, but using a video link for this is fine.

[17.Q] Can we use an electric hot plate for heating samples during the laboratory analysis? [17.A] Yes, you can use any electrical device you bring, There will be a US 110 volt power strip available for each team.

Extreme Retrieval and Delivery Task Questions

[1.Q] We need the following information for estimation of power consumption/torque: The rule mentioned "vertical drops" and "steep slopes in excess of 45 degrees."  Will such "boulders" be only small portions of the route (i.e. only one step drop boulder along the route; only few feet of steep slope) or more of a continuous part of the path (i.e. several step-down paths; continuous climb along a steep path for more than 10 feet)? Should we expect the "steep slopes in excess of 45 degrees" be an angle that is relatively close to 45 degrees? [1.A] The course will feature a range of terrain at increasing levels of difficulty. Teams should expect some easy terrain, some moderate terrain, and some difficult terrain.  Easy terrain may include small isolated drops and shallow slopes. Extremely difficult terrain may include continuous steps, slopes even steeper than 60 degrees with loose soil, and even vertical faces. Exact specifications are purposefully not given, so teams will need to make their own decisions on compromises between capability in this and other tasks, weight, durability, complexity, cost, etc. Such ambiguity is a fundamental tenet of exploration since in real life often you don't know enough information to make the "right" choice, and you need to make educated guesses.  That's part of the fun of real engineering!

[2.Q] When walking on the course before performing the task can we take notes, photos, measure slopes and record other data? [2.A] For this task only, due to the hazards posed to the rovers, teams will be given some official time to scout the course and take notes or photos, but not measurements. The idea is for the rover to explore the area, not astronauts. At other times and for all other tasks see rule 1.g. Ask some of the veteran teams if you want to know where we have set the courses previously, but we make no promises about specific future locations.



Equipment Servicing Task Questions

[1.Q] What are the dimensions of the wagon within the equipment servicing task and how heavy could it be? [1.A] See videos from the 2016 competition, but we would like your design to be flexible enough to handle any reasonable wagon we could come up with. It just needs to carry a fuel can so don't expect anything too large or heavy.

[2.Q] Is there a specific regulator or type of regulator that is going to be used? What is its size? Can you provide details on the rigidity/stiffness of the hose? We are concerned that the weight will make it difficult to remove without a second hand supporting it.  [2.A] The specific type of regulator and hose is to be determined, but shouldn't be of too much relevance to you: We will make sure it is reasonably unscrewed and transferred to another tank by one gloved hand of an astronaut, with the other behind their back! This our basic design criteria for all equipment servicing tasks. The main thing you need to know is that it will have a collar style connection that you will need to unscrew, as specified in the rules. It will be a scuba style DIN regulator which typically has a grooved knob style fitting, but don’t expect it to be that heavy. NASA would probably make something out of titanium or a new high entropy metal not the typical heavy brass you might find.

[3.Q] How full will the fuel can be? Is there a penalty for spilling "fuel"? [3.A] Fullness won't be specified in advance except that it will weigh less than 3kg as in the rule. Yes, you will be partially penalized for spilling your precious fuel on the ground. The ISRU unit works hard to make fuel for you from the Martian atmosphere :- )

[4.Q] How wide will the opening to the fuel tank be? How tall will the O2 tank be?  [4.A] See videos from the 2016 competition. Most equipment will be less than a metre tall.tall.

[5.Q] We read that one end of a rope will have a carabiner attached to it. What about the other end? Will we be able to tie it on to our rover?   [5.A] The tether and carabiner are considered subsystems of the rover and must be provided by each team. It may be integrated into your rover by any means you see fit prior to the event.

[6.Q] The rules say we can make a custom carabiner. Does it need to work like a carabiner or can any design that can be attached and used to tow be used? Can we make it electrically operated using a motor to open and close it? Do we need to be able to detach the carabiner from the wagon? If so, can we leave it on the ground or do we need to be able to stow it on the rover? What exactly is required in the task?  [6.A] Any design is acceptable, may include electrical actuation, and yes, you should be able to detach it. Full retrieval is up to you as a design choice. It might obviously be useful, but you also may not need it for the task. You will have to weigh the potential use vs. the need, effort, and cost. We intentionally do not provide exact requirements to encourage flexibility in design. You should expect a few twists on last year's task, for which you can find videos online.

 

Autonomous Traversal Task Questions

[1.Q] With an autonomous system will the GPS coordinates be enough for the rover to locate the start and finish gates, or will we need some sort of image recognition?
 [1.A] As in rule 3.e.v a radius of 3m is defined as successful. GPS is typically not accurate enough so your autonomous system will need some way to identify the gate markers. 

[2.Q] Will there be any other obstacles on the course other than he tennis balls that are being used to mark the gates? [2.Q] No, just the elevated tennis balls and natural terrain on the course. No QR codes or AR tags, and no physical gates such as on the previous terrain task. However, there may be judges and spectators in close proximity to the rover, and the control station and cars parked by the side of the road may be visible from the course. 

[3.Q] Is communication from a computer in the base station to the rover permissible as long as there is no human intervention? For example, could the base station computer handle some of the calculations required for autonomy?  [3.A] Yes, this will be allowed. It would be difficult for us to verify that you weren't using the base station computers, and the main goal is that there is no human intervention.

[4.Q] Can we restart autonomous navigation at any time without losing points?  [4.A] Yes, you may stop and restart autonomous navigation at any point. However if you stop autonomous navigation you must return to the starting location of that leg to earn points on that leg. See rule 3.e.iv. Most of the URC tasks, this one included, are designed so that while you can fail to earn points, you cannot lose them other than via an intervention. You will be scored on how much of the leg your rover can complete autonomously. Full points will be awarded as in rule 3.e.v. for getting within 3m of the gate, and if not, partial points will be awarded at the discretion of the judge.

[5.Q] How densely populated with tennis ball markers will the path be?  [5.A] The path will not be "dense" at all for the autonomous traversal. You will likely just be given the GPS coordinates of the elevated tennis balls that mark the start and end of each leg. Expect them to be far enough apart your rover will not be guaranteed to be able see the next tennis ball from the previous one (at least using a standard video camera). You will need to drive to approximately the correct location and then find the tennis ball. The route between them will be up to you or your rover depending on how you chose to solve the task.

[6.Q] How accurate will the GPS coordinates be?  [6.A] We will probably just use a handheld GPS to tag each location with a single reading. No multiple readings, no differential GPS, no referencing with a map, etc. The accuracy of each GPS location should be typical of most GPS readings which have a standard deviation of about 5m and 95% confidence level of about 10m, but will depend on factors such as the quality of the GPS system, the number of satellites overhead, obstructions, weather, and interference. As mentioned in Q1 above you should not expect it to be accurate enough to get close enough to successfully complete a leg. You will have to get close and then use your computer vision, prior teleoperated trip, or other methods to accurately locate the tennis ball marker.