NRO declassified "Jumpseat" satellite.

[97prizm]

Hi All,

This popped up and I thought it was interesting as it makes you wonder what we have capability wise now. I still don't understand how the NRO (national reconnaissance office) got the satellite to fly in an elliptical or molniya orbit. Apparently eight were launched and seven made it into orbit.

 

[SC Maintenance]

I think highly elliptical orbits are common - or were - for spy satellites so you get them fairly close to the point on earth you wish to spy on. Perhaps they have been replaced with normal orbits and better camera tech?

The problem isn't getting them into an elliptical orbit - its keeping them there, primarily because the earths mass / gravity is not even so the inclination of the required orbit to get the satellite where you want it causes the orbit to drift (move) relative to the earths surface. There are some mathematical fixes to this.

 

[97prizm]

I think highly elliptical orbits are common - or were - for spy satellites so you get them fairly close to the point on earth you wish to spy on. Perhaps they have been replaced with normal orbits and better camera tech?

The problem isn't getting them into an elliptical orbit - its keeping them there, primarily because the earths mass / gravity is not even so the inclination of the required orbit to get the satellite where you want it causes the orbit to drift (move) relative to the earths surface. There are some mathematical fixes to this.

Supposedly a molniya (Lightning in Russian) orbit is designed to allow the satellite at apogee ie the highest point in its orbit to have more exposure time. It makes me wonder what we have now if "jumpseat" was launched and used in the late 70's until the mid 80's until 2006. The latitude is key according to the article I think 63.5 degrees at release.

 

[mk378]

As another example, the Sirius radio satellites were launched into highly eliptical orbits so they are usable (in line of sight) to the US market area for a larger percentage of time than if they were in circular orbit. They hang out high over the US while moving relatively slowly, then whip around the back side of the Earth quickly.

Edit: Jumpseat was not a camera satellite. It carried a large dish antenna to intercept radio and RADAR signals. It appears the main intent of the program was to find the frequencies and modes that enemy systems used, by detecting their signals during training and testing.