Declassifying JUMPSEAT: an American pioneer in space
by mkmk on 1/29/2026, 1:15:02 AM
Comments
by: unwind
<i>“The historical significance of JUMPSEAT cannot be understated,” said Dr. James Outzen, NRO director of the Center for the Study of National Reconnaissance.</i><p>I'm no native speaker but that is backwards, right? Shouldn't it be <i>overstated</i> if it was a success?
1/31/2026, 6:26:46 AM
by: gpt5
If you are curious what this is about. The US effectively wanted a geostationary satellite parked right over the high-latitude regions of the Soviet Union to intercept their signals.<p>The problem is, that geostationary satellites must orbit directly above the equator. If you try to look at northern Russia from the equator, the curvature of the Earth gets in the way.<p>So, the NRO used a Molniya (HEO) orbit as a clever cheat.<p>They launched JUMPSEAT into a stretched-out ellipse. Because of orbital mechanics, a satellite moves incredibly fast when it's close to Earth (perigee) but slows down dramatically when it's far away (apogee). It spends about 10 hours of its 12-hour orbit just loitering high above the USSR, slowly drifting across the sky, essentially emulating a geostationary satellite.
1/31/2026, 6:21:52 AM
by: sizzzzlerz
This blows me away. I worked on systems that processed the signals from these satellites at the ground sites. At the time, these were highly classified, requiring background investigations and a polygraph to be granted access to know about these things. All our work had to be performed in a SCIF and we were forbidden to discuss our work with anyone not cleared to know. The form that we had to sign when being briefed stated that this was a lifetime commitment. I never would have believed that the NRO would declassify this system.
1/29/2026, 2:32:17 AM
by: mkmk
Declassification memo: <a href="https://www.nro.gov/Portals/135/Documents/foia/JUMPSEAT%20Records/Treated_Limited%20Declassification%20of%20JUMPSEAT.pdf" rel="nofollow">https://www.nro.gov/Portals/135/Documents/foia/JUMPSEAT%20Re...</a>
1/29/2026, 1:16:06 AM