Mro On Approach, TCM-3 not required Options

[Redstone]

MRO has shifted from the cruise phase to Approach phase. Apparently, the trajectory is so good that TCM-3 was cancelled. This is good news for the prospects for a long life for MRO supporting future missions. TCM-4 is on Feb 28, and MOI on March 10. Only 5 weeks away!

[djellison]

Is it just me - or is there some great documentation listed....but not accesable Sort of a wave-candy-infront-of-baby type thing

Doug

[Guest_AlexBlackwell_*]

Is it just me - or is there some great documentation listed....but not accesable Sort of a wave-candy-infront-of-baby type thing

Sorry about that, Doug. I thought only the second "Documentation" link was reserved for team access (i.e., requires a userid and password). It looks as if the first tree is as well.

[jmknapp]

I generated a view of Earth as MRO comes out of occultation on March 10th, based on the "ideal" NAIF kernel:



The above is in spacecraft time not accounting for speed of light. The signal would get to Earth 11 minutes, 58 seconds later, at 22:16:00 UTC (5:16pm EST) .

[Bob Shaw]

I generated a view of Earth as MRO comes out of occultation on March 10th, based on the "ideal" NAIF kernel:


The above is in spacecraft time not accounting for speed of light. The signal would get to Earth 11 minutes, 58 seconds later, at 22:16:00 UTC (5:16pm EST) .

Now, if only that could be photographed during the aerobraking test image campaign...

Bob Shaw

[ugordan]

Now, if only that could be photographed during the aerobraking test image campaign...

Not to mention there haven't been all that many cameras with a 0.005 degree FOV flown on planetary missions...

[djellison]

Not to mention there haven't been all that many cameras with a 0.005 degree FOV flown on planetary missions...

http://hirise.lpl.arizona.edu/HiRISE/image...rise_params.gif
1.14 degrees for HiRISE - which is just a tiny bit more than this much

http://space.jpl.nasa.gov/cgi-bin/wspace?t...orbs=1&showsc=1

Doug

[jmknapp]

1.14 degrees for HiRISE - which is just a tiny bit more than this much

Even so, at HiRISE resolution of 1 urad/pixel, Earth being 59 urad (0.0033 deg) across would be ~59 pixels.

Approximately this resolution (blown up to 512 pixels across):



On the Earthrise time for the HGA, I don't suppose that the Mars atmosphere affects the X-band very much?

[ugordan]

On the Earthrise time for the HGA, I don't suppose that the Mars atmosphere affects the X-band very much?

The effect is probably negligible, even more so due to the fact Mars' atmosphere contains virtually no vater wapor.
The above simulated image would in reality be suspended in a thick reddish tint due to the atmosphere, and the whole Earthrise would have to be very carefully timed even if one knew the precise orbit MRO has -- which obviously won't be the case due to varying performance of the engines during MOI. In short, aiming for this KODAKMMT would be very, very hard and the end result wouldn't be all that rewarding.

[helvick]

In short, aiming for this KODAKMMT would be very, very hard and the end result wouldn't be all that rewarding.

Probably true for this shot but I reckon that a shot of Earthrise over the Martian atmosphere that had this sort of resolution would be a stunningly evocotave picture.

[mcaplinger]

Probably true for this shot but I reckon that a shot of Earthrise over the Martian atmosphere that had this sort of resolution would be a stunningly evocotave picture.

I'm skeptical about that. The relative sizes of Mars and the Earth from martian orbit make an Apollo-style Earthrise picture impossible. And the martian limb is pretty diffuse. With the degree of magnfication required to resolve the Earth, the limb would be huge and probably featureless. I tried to take a "Phobos rising over the limb" image with MOC (see http://www.msss.com/mars_images/moc/2003/06/23/ ) but test images of the limb with the NA were so bad that I quit trying to get the limb and Phobos in the same NA swath (which was hard anyway due to timing and data volume constraints.)

[JRehling]

I'm skeptical about that. The relative sizes of Mars and the Earth from martian orbit make an Apollo-style Earthrise picture impossible. And the martian limb is pretty diffuse. With the degree of magnfication required to resolve the Earth, the limb would be huge and probably featureless.

Consider the opposite. Could we usefully take a picture from Earth orbit of Marsrise (or Venusrise/Jupiterrise)? From Hubble? From a weather satellite? From a mountaintop? All signs point to "no"! If the pointing and magnification were precisely done, the atmospheric interference would be terrible. I'm not sure what the optical properties of the martian atmospheric column are, but I bet a double horizon-pointing vector with all the dust and that scale height would be pretty bad.

The timing would also have to be exquisite. Forget about color! [I have in my living room that famous silhouette of a tree, an adult, and a child, in front of the full Moon. That picture (if "real"?) would have required exquisite timing itself, but at least only the Moon was moving.]

If I saw someone take a ground-based picture of Jupiterrise on Earth, I'd start to consider the martian Earthrise feasible.

[lyford]

Consider the opposite.

Something like this?



(Apologies if the image is too large - please let me know - I try to keep everything under 100k and 640px wide)

Though I think this shot will be a fantasy for some time to come....