NROL-77, probably a new NOSS (or maybe not)

click map to enlarge

On 9 December 2025 between 19:06 and 19:28 UTC, SpaceX will launch the classified mission NROL-77 for the NRO, from SLC-40 in Cape Canaveral. The NRO Press Kit is here.

Navigational Warnings point to initial launch into a ~49 degree inclined coasting orbit. Upon passing the descending node of that parking orbit, about an hour after launch, the Falcon 9 upper stage with payload will manoeuver into a ~63.4 degree inclined orbit, likely ~1000 x 1200 km. The upper stage deorbits at the end of the first revolution, in the eastern Pacific.

I initially briefly comtemplated a higher, more unusual orbit, at 1950 km altitude, based on the ~14 minute daily shift backwards of the launch window (as gleaned from Navigational Warning NAVAREA IV 1337). That was an overinterpretation (I blame the COVID infection I suffered the past week, it messes with the brain): the NOSS-like 1000 x 1200 km orbit is more likely and it fits the location and shape of the upper stage deorbit area well.

So this could be a new NOSS (Naval Ocean Surveillance System) duo of SIGINT satellites. Or maybe not, after the experience with NROL-85 in 2022 (see earlier blog post here) which featured only one payload, not two as is typical for NOSS missions. We'll see.

Below are the relevant Navigational Warnings, and two search orbits, one for the coasting orbit (valid untill ~1 hour after launch), the second for the payload(s). 

 

040948Z DEC 25
NAVAREA IV 1337/25(11,26).
NORTH ATLANTIC.
FLORIDA.
1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 
   091906Z TO 092010Z DEC, ALTERNATE
   101852Z TO 101956Z, 111838Z TO 111942Z,
   121824Z TO 121928Z, 131810Z TO 131914Z,
   141756Z TO 141900Z AND 151742Z TO 151846Z DEC
   IN AREAS BOUND BY:
   A. 30-50.00N 078-10.00W, 32-12.00N 077-07.00W,
      32-27.00N 076-28.00W, 32-03.00N 075-57.00W,
      31-38.00N 076-07.00W, 30-40.00N 077-57.00W.
   B. 28-39.69N 080-38.17W, 28-52.00N 080-15.00W,
      28-45.00N 080-03.00W, 28-29.00N 080-22.00W,
      28-27.61N 080-31.56W.
2. CANCEL THIS MSG 151946Z DEC 25.//

 

040904Z DEC 25
NAVAREA XII 789/25(21,22,83).
PACIFIC OCEAN.
1. HAZARDOUS OPERATIONS, SPACE DEBRIS
   1731Z TO 2200Z DAILY 09 THRU 15 DEC
   IN AREA BOUND BY
   12-02.00N 112-31.00W, 12-58.00N 114-47.00W,
   00-49.00S 120-38.00W, 01-46.00S 118-25.00W.
2. CANCEL THIS MSG 152300Z DEC 25.//

 

Search orbits:

NROL-77 PARKING                 for launch on 9 Dec 2025 19:06:00 UTC
1 70000U 25999A   25343.79583334  .00000000  00000-0  00000-0 0    03
2 70000 049.1163 258.3583 1136647 049.6536 329.5142 13.42495109    02

NROL-77 NOSS payloads           for launch on 9 Dec 2025 19:06:00 UTC
1 70001U 25999A   25343.83680556  .00000000  00000-0  00000-0 0    03
2 70001 063.4415 271.5212 0133723 213.5444 360.0000 13.42495109    02

 

image: NRO

 (with thanks to Ted Molczan for discussions)