NROL-85 | Falcon 9 Block 5

Lift Off Time
April 17, 2022 – 13:13 UTC | 06:13 PDT
Mission Name
NROL-85, a classified mission for the NRO
Launch Provider
(What rocket company launched it?)
SpaceX
Customer
(Who paid for this?)
National Reconnaissance Office
Rocket
Falcon 9 Block 5, B1071-2; 73.70 day turnaround
Launch Location
Space Launch Complex 4 East (SLC-4E), Vandenberg Space Force Base, California
Payload mass
Unknown, no more than ~10,000 kg
Where did the satellites go?
Initial orbit: 1,220 km x 1,024 km low-Earth orbit at 63.5°; final orbit unknown
Did they attempt to recover the first stage?
Yes
Where did the first stage land?
B1071-2 successfully landed on Landing Zone 4 (LZ-4) at Vandenberg Space Force Base
Did they attempt to recover the fairings?
Yes, NRC Quest attempted to recover both fairing halves
Were these fairings new?
Yes
This was the:
– 148th Falcon 9 launch
– 88th Falcon 9 flight with a flight proven booster
– 92nd re-flight of a booster
– 13th re-flight of a booster in 2022
– 114th booster landing

40th consecutive landing (a record)
– 14th launch for SpaceX in 2022
– 22nd SpaceX launch from SLC-4E
– 41st orbital launch attempt of 202
2 (40th successful)
Where to watch
Official Replay

How Did It Go?

SpaceX successfully launched the NROL-85 mission to low-Earth orbit on their Falcon 9 Black 5 vehicle. Launching from Space Launch Complex 4 East, two classified satellites were placed into a low-Earth orbit while the Falcon first stage attempted a soft landing on Landing Zone 4.

NROL-85 Mission

It is thought that the pair of satellites are part of the NRO’s Intruder mission, which is part of the US Navy’s Naval Ocean Surveillance System (NOSS). NOSS was created during the 1970s with the goal of creating an accurate geolocation map of all of the USSR’s ground and sea assets. The satellites are signal intelligence (SIGNIT) satellites.

Due to the classified nature of the NRO, no more details are known about the satellites.

What Is Falcon 9 Block 5?

The Falcon 9 Block 5 is SpaceX’s partially reusable two-stage medium-lift launch vehicle. The vehicle consists of a reusable first stage, an expendable second stage, and, when in payload configuration, a pair of reusable fairing halves.

First Stage

The Falcon 9 first stage contains nine Merlin 1D+ sea level engines. Each engine uses an open gas generator cycle and runs on RP-1 and liquid oxygen (LOx). Each engine produces 845 kN of thrust at sea level, with a specific impulse (ISP) of 285 seconds, and 934 kN in a vacuum with an ISP of 313 seconds. Due to the powerful nature of the engine, and the large amount of them, the Falcon 9 first stage is able to lose an engine right off the pad, or up to two later in flight, and be able to successfully place the payload into orbit .

The Merlin engines are ignited by triethylaluminum and triethylborane (TEA-TEB), which instantaneously burst into flames when mixed in the presence of oxygen. During static fire and launch the TEA-TEB is provided by the ground service equipment. However, as the Falcon 9 first stage is able to propulsively land, three of the Merlin engines (E1, E5, and E9) contain TEA-TEB canisters to relight for the boost back, reentry, and landing burns.

Second stage

The Falcon 9 second stage is the only expendable part of the Falcon 9. It contains a singular MVacD engine that produces 992 kN of thrust and an ISP of 348 seconds. The second stage is capable of doing several burns, allowing the Falcon 9 to put payloads in several different orbits.

For missions with many burns and/or long coasts between burns, the second stage is able to be equipped with a mission extension package. When the second stage has this package it has a gray strip, which helps keep the RP-1 warm, an increased number of composite-overwrapped pressure vessels (COPVs) for pressurization control, and additional TEA-TEB.

Falcon 9 Block 5 launching on the Starlink V1.0 L27 mission (Credit: SpaceX)

Falcon 9 Booster

The booster that supported the NROL-85 mission is B1071-2. As the name implies, the booster had supported one previous mission: NROL-87, which launched on February 2, 2022 at 20:27.

Following stage separation, the Falcon 9 conducted three burns. These burns softly touch down the booster on SpaceX’s landing zone LZ-4.

falcon 9 booster, landing, drone ship
Falcon 9 landing on Of Course I Still Love You after launching Bob and Doug (Credit: SpaceX)

Falcon 9 Fairings

The Falcon 9’s fairing consists of two dissimilar reusable halves. The first half (the half that faces away from the transport erector) is called the active half, and houses the pneumatics for the separation system. The other fairing half is called the passive half. As the name implies, this half plays a purely passive role in the fairing separation process, as it relies on the pneumatics from the active half.

Both fairing halves are equipped with cold gas thrusters and a parafoil which are used to softly touch down the fairing half in the ocean. SpaceX used to attempt to catch the fairing halves, however, at the end of 2020 this program was canceled due to safety risks and a low success rate. On NROL-85, SpaceX attempted to recover the fairing halves from the water with their recovery vessel NRC Quest.

In 2021, SpaceX started flying a new version of the Falcon 9 fairing. The new “upgraded” version has vents only at the top of each fairing half, by the gap between the halves, whereas the old version had vents placed spread equidistantly around the base of the fairing. Moving the vents decreases the chance of water getting into the fairing, making the chance of a successful scoop significantly higher.

All times are approximate

HR/MIN/SEC EVENT
00:38:00 SpaceX Launch Director verifies go for propellant load
00:35:00 RP-1 (rocket grade kerosene) loading underway
00:35:00 1st stage LOX (liquid oxygen) loading underway
00:16:00 2nd stage LOX loading underway
00:07:00 Falcon 9 begins engine chill prior to launch
00:01:00 Command flight computer to begin final prelaunch checks
00:01:00 Propelant tank pressurization to flight pressure begins
00:00:45 SpaceX Launch Director verifies go for launch
00:00:03 Engine controller commands engine ignition sequence to start
00:00:00 Falcon 9 liftoff

Launch and Landing

All times are approximate

HR/MIN/SEC EVENT
00:01:12 Max Q (moment of peak mechanical stress on the rocket)
00:02:16 1st stage main engine cutoff (MECO)
00:02:20 1st and 2nd stages seperate
00:02:33 1st stage boostback burn begins
00:03:15 Fairing deployment
00:03:21 1st stage boostback burn complete
00:06:15 1st stage entry burn begins
00:06:36 1st stage entry burn complete
00:07:28 1st stage landing burn begins
00:08:00 1st stage lands on Landing Zone 4

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