[X] My Assistant

[Marcel]

Does anybody know when and how many MSL will go, or when the decision on this will be made ?

[Guest_BruceMoomaw_*]

Well, the antenna doesn't have any mast to speak of -- it just sits on a 2-axis gimbal sitting right on the rover's deck. Second, as Mike Caplinger says, it's much too big to be supported by the camera mast. Anyway, the separate camera motors are miniscule in weight compared to the whole DTE system -- you wouldn't be saving any weight to speak of (and probably none, since you'd have to provide a stronger, heavier camera mast to support the antenna as well).

[Guest_exobioquest_*]

BruceMoomaw

Well I figure the thing was as light as small satellite dish. Forgive me for thinking jpl could at least equal the capabilities of satellite television provider.

When i said mast, I meant the slender vertical structure that holding up the dish in the picture you provided, forgive me if there is some other word for it.

mcaplinger,

Seriously, I feel I may I might have offended you with that suggestion, take no offense I’m not challenging you, quite the opposite: I want to understand. If I ask why not do something differently I’m simply wondering why you did it like that, I’m not trying to make suggestion into a field that is very foreign from my own, rather I’m looking to be answered and enlightened, not respected. If something seems wrong to me I’ll ask the experts why it like that, why it’s not done the way I think it should be, they will hopefully explain to me, I will argue with them until I understand why it like that and then it won’t seem wrong to me anymore. Most people ask why and are given a simple answer, usually they don’t feel the answer was adequate but don’t ask for further explanation out of fear of being embarrassed for some perceive stupidity of not understanding already. I lacking a sense of honor or dignity and I’m willing to make a fool of my self until I understand.

So please don’t get angry with further questions like why not design the “MastCam” to handle the weight, why would two separate structures weigh less then one?

[mcaplinger]

If something seems wrong to me I’ll ask the experts why it like that, why it’s not done the way I think it should be, they will hopefully explain to me...

I think Bruce explained it pretty well. The mass of the motors and antenna is only a small fraction of the whole DTE system (if the total mass of that is 50 kg, they really aren't trying very hard, but that's another story) and trying to cantilever more mass up at the top of the RSM, which has to be stable enough to support Mastcam imaging, has to move rapidly to take mosaics, is a meter or more off the ground when the antenna has no need to be that high -- well, it just wouldn't end up saving mass.

Not the mention the fact that they have to have a fat waveguide between the power amps and the transmitter (presumably in the main rover warm box) and the antenna.

But we're just designing the cameras. JPL designs the mast and its pointing and deployment mechanisms. All I can say is that the RSM design is hard enough to make work as it is.