MTO Cancelled Options

[Guest_BruceMoomaw_*]

I've been looking more into how good various techniques may be for measuring near-surface Martian winds, and I've managed to dredge up a few interesting items:

(1) While MRO's original SDT report said that a microwve limb sounder couldn't measure winds below 40 km, the French MAMBO limb sounder that they had planned to install on their Netlander-carrying Mars orbiter would supposedly have been able to do so -- with the sensitivity required by MEPAG -- down to only 20 km: http://www.lmd.jussieu.fr/Planeto/mambo.pdf

(2) The Upper Atmosphere Research Satellite had a Fabry-Perot interferometer for the purpose (the "High Resolution Doppler Imager") that could supposedly measure winds down to only 10-15 km by comparing Doppler shift in the emission lines of O2 -- which is down to depths well below the surface air pressure of Mars:
http://hrdi.engin.umich.edu/publications/p...eetingpaper.pdf
http://www.earth.nasa.gov/history/uars/uars1.html

The first of those documents, written in 1993, says that at that time "The algorithms for the stratospheric inversions are still under the final stages of development. However, they are at a level sufficient to resolve the gross characteristics of the stratospheric wind field as illustrated in Fig. 11. This shows the wind field on September 7, 1992 at 30 km." I haven't been able to find out how much the UARS wind measurements from this instgrument have been improved by further analysis since then (it stopped working in 1995).

(3) Regarding Doppler wind lidar: this instrument is very complex and heavy if it is to be used to try to measure wind speeds well down in earth's bulky atmosphere (it will probably need a 30-cm telescope, among other things). But a June 2005 paper ( http://esto.nasa.gov/conferences/estc2005/...ations/B7P1.pdf ), which mentions current development work on a Mars wind lidar (pg. 27-37), says that "Wind measurements are easier on Mars than Earth. A relatively modest lidar would do the job on Mars [due to] lower orbit height [and] more aerosols/dust."

In short, it appears that there are one or two additional approaches which could make surface wind measurements feasible from the MSTO even if its microwave limb sounder proves inadequate for the purpose.

[nprev]

Sorry to ressurrect a truly ancient thread, but can anyone point me to some public-source data on MTO's now-defunct lasercomm payload? Interested in the freq, power, modulation/encoding protocols, etc. Thanks!

[monitorlizard]

nprev, this is an abstract in its entirety from SPIE publication "Free-Space Laser Communications Technologies XVIII", published Feb. 2006:

MARS LASER COMMUNICATION DEMONSTRATION: WHAT IT WOULD HAVE BEEN

The Mars Laser Communications Demonstration Project completed a preliminary system design for sending data at 1-30MBPS from a spacecraft orbiting Mars. The flight transceiver diameter was 30.6 cm, transmitting 5 W average laser power at 1064 nm and using 32- and 64-ary pulse position modulation (PPM). A ground network comprised of two receive terminals (5-m and 1.6-m effective diameter) and two transmit terminals for sending 1076 nm lasers would have been used to communicate with the transceiver.

This is the experiment that would have been on the 2009 MTO spacecraft. BTW, the abstract is free, but the technical paper would cost $18 - $20.

[nprev]

Exactly what I needed...thanks, Monitor!