Echostar 8 Moving

[whatchel1]

Steerable spot

Unless the spots are steerable (unlikely) they will wind up pointing into Atlantic on the E. The W beams will wind up pointing at mostly empty areas of the mountains.

 

[TheKrell]

I claim they will have to rotate the satellite somewhat so that the conus beam approximately illuminates conus. In that case, I doubt the spots will be all that far off. But I agree they'll probably not be aimed at their former markets and may not be used at all.

 

[Fitzie]

What are the problems involved in rotating the satellite slightly?

Thanks in advance for any information on the subject. Or, if there is an appropriate link that contains the information that would be fine.

Fitzie

 

[TheKrell]

Unless I am sorely mistaken, all Echostar satellites are 3-axis stabilized spacecraft using momentum wheels (gyroscopes) to maintain their orientation. So, using a bit of electrical power, they can point the fixed antennas quite easily and accurately. This attitude control is going on continuously to rotate the satellite once/day, or else the antennas would be pointed at a fixed point in space and only occasionally point in the right direction.

The big problem in the fleet is of course Echo 5 (129) which has had multiple failures of it's momentum wheels. It must use it's precious supply of on-board fuel and small rocket thrusters to maintain orientation. That supply of fuel will be exhausted some time next year.

 

[Fitzie]

Unless I am sorely mistaken, all Echostar satellites are 3-axis stabilized spacecraft using momentum wheels (gyroscopes) to maintain their orientation. So, using a bit of electrical power, they can point the fixed antennas quite easily and accurately. This attitude control is going on continuously to rotate the satellite once/day, or else the antennas would be pointed at a fixed point in space and only occasionally point in the right direction.

The big problem in the fleet is of course Echo 5 (129) which has had multiple failures of it's momentum wheels. It must use it's precious supply of on-board fuel and small rocket thrusters to maintain orientation. That supply of fuel will be exhausted some time next year.

Thanks to TheKrell for the information. I was aware of some of the momentum wheel failures, but thought generally the satellites sit mostly motionless in a manner similar to the moon, i.e., facing the earth at all times. (Recognizing the moon circles the earth at a regular period.) Still, if I understand the comment, it should be simple to make a programming change to reorient the satellite and then maintain it at it's new orientation (using the momentum wheels) with no loss of fuel other than that used in making the reorientation.

That being the case, there would seem to be no reason not to use E8 for either CONUS programming or spot beams, or both. But, if that's not the case, I'd appreciate being told so. (Current location per n2yo, 77.95W, Altitude 22,155M.)

Thanks again,
fitzie

 

[Smith P.]

Some reading like this GMAT Wiki Home : LEO Station Keeping will give some input.
Or just use Wiki.

 

[rocatman]

Some reading like this GMAT Wiki Home : LEO Station Keeping will give some input.
Or just use Wiki.

I think you mean GEO Station Keeping i.e., Geostationary Earth Orbit. LEO is Low Earth Orbit like the orbit of the Shuttle or the International Space Station.

 

[harshness]

Passing 77W on Wednesday.

ECHOSTAR 8
1 27501U 02039A 08301.75418551 -.00000250 00000-0 10000-3 0 2903
2 27501 000.0273 284.0060 0003713 340.0744 326.0068 01.00408642 22683

 

[Smith P.]

I think you mean GEO Station Keeping i.e., Geostationary Earth Orbit. LEO is Low Earth Orbit like the orbit of the Shuttle or the International Space Station.

Yeah, sure, there is difference, but common rules still the same - my point is: just look around .

 

[J. Allen Head]

77.6 and still at the moment

 

[harshness]

Actually, it is still moving according to the TLE I posted yesterday.

 

[Fitzie]

W77.26 at 8:03 p.m. est.

 

[Smith P.]

Changed plans - going to 61.5W location

 

[play.pikachu]

hi! i´m play.pikachu

excuse me sir, what exactly do you mean with "Changed plans - going to 61.5W location"?

 

[alebowgm]

I think he is joking

 

[Fitzie]

Current location, 77.19W, Altitude 22,173 miles and ascending. My conclusion is the satellite has reached it's destination (77W) and is preparing for a full stop at it's geostationary orbit.

Regarding PSmith's comment, based on his emoticon--

--I would guess he's making a little joke, because a number of regulars on this site have been tracking E8's movements daily, including whether it has sped up or apparently slowed down.

Unless recently received, Dish Network still has to receive authority to broadcast from that location, 77W, which is assigned to Mexico. Presumably (but not logically) E8 could be sent on to 61.5, or returned to 110W, or moved on to 72.7, or...well, just wherever or whatever. Personally, I'm now going to start watching for news releases from Dish stating what their next move is.

Best regards,
fitzie

 

[alebowgm]

Presumably (but not logically) E8 could be sent on to 61.5, or returned to 110W, or moved on to 72.7, or...well, just wherever or whatever.

148w

 

[HDRoberts]

Should be close enough to start anytime. Time for those more skilled than me to swing their dishes to 77W to see if anything pops up. I'm thinking Mexico doesn't have a fancy online docket system to let us know when approvals are received.

 

[photoman76]

No new activity at this time. The Broadlogic Spectrum analyzer only shows the four existing Mexican transponders on Echostar 4.

 

[harshness]

The latest TLE shows about 50 minutes to crossing 77W but it will do so at a pretty good pace.

ECHOSTAR 8
1 27501U 02039A 08302.43889834 -.00000248 00000-0 10000-3 0 2913
2 27501 000.0279 285.8042 0003837 330.0769 221.6998 01.00402901 22696