According to JSR 674...
"By Feb 10, TDRS K was in a 35422 x 35787
km x 7.1 deg orbit over 150 deg West, drifting east at 2 deg/day..."
Isn't it odd to be at GEO distance yet still have 7 degrees of inclination? I thought the final burn to GEO usually zeroed out the inclination.
Is there still one more burn left?
According to JSR 674...
"By Feb 10, TDRS K was in a 35422 x 35787
km x 7.1 deg orbit over 150 deg West, drifting east at 2 deg/day..."
Isn't it odd to be at GEO distance yet still have 7 degrees of inclination? I thought the final burn to GEO usually zeroed out the inclination.
Is there still one more burn left?
Probably not. Data relay satellites like TDRS does not require such a stringent requirement of north-south keeping, as the signal beams receivers are very large antennas (unlike those small satellite dishes that communication satellites users have), so it is better to conserve fuel and let the oblate Earth do the job of lowering the inclination over the next few years.
According to JSR 674...
"By Feb 10, TDRS K was in a 35422 x 35787
km x 7.1 deg orbit over 150 deg West, drifting east at 2 deg/day..."
Isn't it odd to be at GEO distance yet still have 7 degrees of inclination? I thought the final burn to GEO usually zeroed out the inclination.
Is there still one more burn left?
Probably not. Data relay satellites like TDRS does not require such a stringent requirement of north-south keeping, as the signal beams receivers are very large antennas (unlike those small satellite dishes that communication satellites users have), so it is better to conserve fuel and let the oblate Earth do the job of lowering the inclination over the next few years.
Doesn't inclination usually INCREASE with time on orbit? It usually becomes an issue as satellites run low on fuel to maintain a low inclination--or so I thought...
According to JSR 674...
"By Feb 10, TDRS K was in a 35422 x 35787
km x 7.1 deg orbit over 150 deg West, drifting east at 2 deg/day..."
Isn't it odd to be at GEO distance yet still have 7 degrees of inclination? I thought the final burn to GEO usually zeroed out the inclination.
Is there still one more burn left?
Probably not. Data relay satellites like TDRS does not require such a stringent requirement of north-south keeping, as the signal beams receivers are very large antennas (unlike those small satellite dishes that communication satellites users have), so it is better to conserve fuel and let the oblate Earth do the job of lowering the inclination over the next few years.
Doesn't inclination usually INCREASE with time on orbit? It usually becomes an issue as satellites run low on fuel to maintain a low inclination--or so I thought...
I'm not familiar with the math, but I understand the inclination oscillates between 0 and some value i-max. If you start at 0, it will start heading away from 0. If you start at some other part of the cycle, whether it heads up or down depend on the detailed parameters.
And isn't it mostly lunisolar rather than oblateness?
Boeing Communications Relay Satellites Complete Space, Earthly Testing
NASA accepts 1st orbiting TDRS satellite in 10 years
TDRS-L clears ground performance tests, awaits delivery
EL SEGUNDO, Calif., Aug. 20, 2013 -- Two Boeing [NYSE: BA] Tracking and Data Relay Satellites (TDRS) have completed testing milestones – one in space and the other on Earth – marking more progress in enhancing the tracking and communications network used by NASA and its customers.
The orbiting TDRS-K satellite has completed all testing since its January launch and has officially been handed over to NASA, providing another vital information link between low-Earth-orbiting spacecraft and NASA’s satellite control centers.
The next satellite in the program, TDRS-L, completed performance testing at the Boeing satellite facility in El Segundo and is ready for shipment to Kennedy Space Center, Fla., later this year in advance of a 2014 launch.
TDRS-K and TDRS-L are the first two of a set of three next-generation satellites that features improved payload capacity and enhanced communications bandwidth at the lowest cost.
"These state-of-the-art satellites represent a major step forward in improving high-resolution image, video, voice and data transmission," said Craig Cooning, Boeing Space & Intelligence Systems vice president and general manager.
The third satellite in the series, TDRS-M, completed a critical design review with NASA and is now in the production phase and available for launch in 2015. Boeing built the previous set of three TDRS satellites – H, I and J – which have been in use since 2000 and 2002.
