Abstract

Satellites and antennas 
  Satellite Network
  Specifications

On Mars Communication
  Radio Communications
  Radio Specifications

LMR Software and Control

DSP and Noise Correction

Communication and Software
Abstract

The communications and software design team has dealt with challenges regarding the transmission and reception of data between any launched apparatus and Mission Control. We have devised a system of satellites to maintain constant contact between Earth and Mars despite the respective rotations of those planets. Furthermore, we have outlined how the astronauts and the robots will interact with one another via radio transmission. The astronauts and robots also will be able to communicate via satellite if it becomes necessary. Finally, we have designed programs for the rover control  and have written preliminary noise protection algorithms that will ensure that any data sent will be received in a readable state.

Many complications were faced as communication and software plans were made for this mission.  The distance and pure volume of necessary transmissions were daunting.  Since communications between the vehicles and Earth will be critical to the success of the mission, data loss must be minimal.  The choice of bandwidth was easy due to restrictions caused by the distance being traveled, the availability of non-commercial bands, and reliability requirements. Satellite hardware was also not a difficult choice.

One major problem encountered was that of communication on the Martian surface.  The LMRs will be traveling great distances and sending data back to the main base.  However, the LMRs only have 16 available watts of power, making direct transmission to the satellites in orbit around Mars impossible.  The idea of relays was extensively researched and discussed without any satisfactory conclusion being reached.  The robotics team eventually came up with the idea of medium-sized rovers with the capability to transmit to the satellite.  The rovers will move in a convoy that allows to LMRs to remain in contact with the medium-sized rover, thus providing communication to the main base.

Another challenge was that of protecting the data during transmission. Reed-Solomon data protection codes will be employed to remove noise.  These codes was chosen above others for their proven quality and reliability.

We have been assigned a reasonable budget that should more than allow for any purchases and retrofitting as needed.  Multiple flights within the mission were also highly discussed.  Two flights were decided upon, but a third flight will now be made separately for the satellites due to weight constraints.  This flight will precede the others and permit the establishment of communications before the rest of the interplanetary vehicles arrive.

Although there were many communication and software challenges to be faced in the planning of this mission, there is now a concrete plan that will provide safe and reliable transmission of data. 

Authors: Victoria Davis (vdavis@mit.edu) and David Broniatowski (sabrevln@mit.edu)


 
 
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Comments and questions to mission2004-students@mit.edu Last updated: 10 December, 2000