At the beginning of their missions, both Spirit and Opportunity generated 800 watts of power. I did some searching from the web, and the solar panels I found sold commercially only generate 125 watts at most. I'm far from being an expert in solar power, but how could the solar panels on MER generate far more power on Mars than ones available here on Earth? Does NASA have more advanced solar panels that are not available commercially?

Yes - they are very very expensive, very very efficient cells - but - they only generate roughly 140 watts at any one time.

The 600 - 800 values are watt-HOURS....i.e. the equiv of 100 watts for 8 hours. It's a cumulative total ammount of power generated in an entire sol.

Given 10 hours of sunlight - a 125 watt array would generate 1250 Watts in a day - ignoring the angle of incidence.

Doug

Doug's right. The cells themselves are very efficient (~23%) when compared to commercial\consumer cells (14% at best).

However the key point is the one that Doug made - the power we are talking about when discussing the rovers is the Watt-Hours they produce per day. The arrays themselves only produce around 100Watt's peak power output at any instant.

Some facts. The total array area is 1.2m^2, they are GaInP/GaAs/Ge Triple Junction cells. At mars the peak insolation (in orbit) varies from ~500 Watts/m^2 to ~700Watts/m^2 (vs ~ 1367 at earth). The theoretical maximum amount of solar flux at Spirits landing site ranges from around 2900 watt hours to around 4300 watt hours per day as the year progresses from mid winter to mid summer. Theoretical being : A- very approximately based on an ideal panel always perfectly facing the sun B- no atmospheric losses and C- lots of other stuff.

Given RTG power - MSL is expected to have about 2200ish Whr's

Doug

Predictable and reliable Watt hours 24.65979 hours per sol too no matter where you decide to roam - could even go caving in some of those intriguing lava tunnels in places like this

With that much power they could add a light source on the rover too, if they wanted to do roving at night

The possibilities with MSL are going to be HUGE

Thanks guys.

No need for that with an infrared-sensitive CCD on the mast
Will it have this feature in it's camera's ? My 700 USD Sony Camcorder has it (0 lux readout).

Might be cool however to have a somewhat focussed heat source (high output infrared LED array) on it's head to aid standarized thermal emission/adsorption spectra of rocks/soil....

The current CCDs on the MERs are also sensitive to near IR, like most CCDs, and have several IR filters. They are not sensitive to longwave "thermal" IR though and can't see at night. MiniTes, however IS sensitive to the thermal IR region! I wonder if a night-time survey could be justified somehow? I bet it would be really neat to see even a very low res far IR glowing image of gusev at night from the top of the hill!

One of the zillion things I wish the rovers had is a real thermal infrared camera. They did take some MiniTES data, don't know about images, at night for surface physical properties analysis. The heating up/cooling down curves tell a lot about grain size and/or cementation of soils, and thermal conductivity stuff about rocks.

You want a cooled detector.. doesn't have to be cryogenic, but below CO2 ice temp helps... wavelength is say 20 to 40 micrometers. CCD cameras work out to about 1.0 or 1.1 max micrometers. "Middle" infrared <definitions vary with discipline> covers reflected radiation from 1 micrometer to about 5 micrometers, where sunlit hot soils start to produce thermal emissions in the afternoon. Beyond 5 micrometers, solar illumination drops more and more and thermal emission takes over. 5 to 15 micrometers work in the daytime, but at night and in winter, you need wavelengths longwards of 15 micrometers to get enough thermal emission to spit at. (15 micrometers is the big atmosphere CO2 opacity band.. Rovers use it to measure atmosphere thermal structure from beneath, orbiters do from above.)

A 1-day time lapse image from a thermal IR camera would really tell you a lot about physical properties of rocks and soils we just can't get much of from MiniTES with it's limited sampling at any station during day and night and it's essentially non-imaging resolution. The maps it can make are wonderful scientifically,but they're spectral maps, not images except in the crudest sense.

Oh, Well...