Can any one guess the Antenna Type? I have never seen T shaped antenna on any planetary rovers
QuoteThus, the Chandrayaan-2 Rover solar panel may be expected to see temperature of Teq = - 182.07374 degrees Creally?!? to the fifth decimal???
Thus, the Chandrayaan-2 Rover solar panel may be expected to see temperature of Teq = - 182.07374 degrees C
Oh, and how are they going to tackle the ultra-low nighttime temperatures? Are they going to use RTGs as well?
[/font]http://news.ninemsn.com.au/technology/2014/01/28/11/14/chinese-lunar-rover-cutely-broadcasts-own-death
Quote from: antriksh on 01/28/2014 07:33 amCan any one guess the Antenna Type? I have never seen T shaped antenna on any planetary roversMaybe they want to let the Rover receive and watch the new digital HD Doordarshan
Quote from: sanman on 01/28/2014 08:01 amOh, and how are they going to tackle the ultra-low nighttime temperatures? Are they going to use RTGs as well?Only If they can develop RTG on time, else they will use the old trusted active thermal management method of ISRO flex heater bank + rechargeable batteries + solar panels.
Only If they can develop RTG on time, else they will use the old trusted active thermal management method of ISRO flex heater bank + rechargeable batteries + solar panels.
What about some kind of phase change material, which could provide some "thermal mass" to buffer the temperature changes? Or would the amount of material required make it too heavy and mass-inefficient? You're only trying to heat the electronics to prevent them from being damaged, right? With nifty lightweight insulators like aerogel, maybe it could be done that way.
What about some kind of phase change material, which could provide some "thermal mass" to buffer the temperature changes? Or would the amount of material required make it too heavy and mass-inefficient?
You're only trying to heat the electronics to prevent them from being damaged, right? With nifty lightweight insulators like aerogel, maybe it could be done that way.
Running off a battery for 20 odd days is going to be a real challenge. So much so that I think lunar night operations demand a Radio-isotope heater unit. Doesn't have to be RTG, but something that provides the heat. You'd radiate the heat during day-time operations, and fold up the radiator for night time ops.But that's a guess. Anyone know if any of the probes that've been to the moon endured a lunar night (or several), and used only batteries (+heaters)?
My guess is that ISRO will also move the rover inside the lander during lunar night for extra protection.
Quote from: antriksh on 01/28/2014 11:27 amMy guess is that ISRO will also move the rover inside the lander during lunar night for extra protection. I thought of that when Yutu started having issues. But that has its own attendant problems. First, as sanman's been saying: dust. You drive the rover back, and you'll bring whole heaps of dust into the lander. Secondly, any deployment mechanism that will essentially have to be reversible will cost mass. (Letting something down onto the lunar surface can use frangible nuts/ cut wires etc. / exploit lunar gravity - but bringing something back up will require a motor. Sure You can simply open up a ramp and let the rover drive down and up along it as depicted in the picture, but then a) you need a ramp and b) folding that on top of the rover (presumably) to offer thermal protection would need a motor. If you didn't plan on getting the rover back into its place, then you could've simply had "drop down" MLI on top of the rover, which covers the vacant space once the rover leaves.Thirdly, from a science perspective - you're going to limit the rover's range and traverses if it has to get back to the lander each time. This may be the case anyway if we have only a rover and lander (rover needs to stay within communication range)... but the diagram depicts an orbiter too. (Which would allow the rover a free rein).But if they do decide to do this, then you can turn 1 & 3 into an advantage by getting the rover to sample dust and ejecta from different locations (assuming you put some sort of mini-lab on the lander that can do this analysis. Or shift the instrumentation from the rover to the lander; and make the rover more durable, and lighter.) As for 2 - maybe beef up one solar array structurally, and have it serve as the ramp. And cover it with Corning Gorilla Glass (TM) as a scratch-guard. That'll be a public outreach coup
Also, how effective will be the tiny rectangular/square microstrip patch antenna in communication with the orbiter?
EDIT: Time to look like an idiot. Spirit and Opportunity are insulated with aerogels. As was Sojourner. So there's obviously something I'm not considering.
The Mars rovers used aerogel as the Martian atmosphere is thick enough so that multi layer insulation (MLI) is not effective. On the Moon, there is no atmosphere so using MLI is sufficient. There is no need to use aerogel on the Moon.
AJA, are you aware that you ended up describing MLI?
In its basic form, it does not appreciably insulate against other thermal losses such as heat conduction or convection.
Spacecraft also may use MLI as a first line of defense against dust impacts. This normally means spacing it a cm or so away from the surface it is insulating.
something with legs?
The project is likely to be completed by 2016-17.
Also, a few landing sites have been shortlisted based on the images obtained from earlier Moon missions. A special team is constructing the Lander.