Falcon 9 to launch NROL-85 mission for National Reconnaissance Office

Date:
Sun, 17 Apr 2022 12:57:11 +0000

Description:
SpaceX will launch a pair of ocean surveillance satellites for the National Reconnaissance Office on The post Falcon 9 to launch NROL-85 mission for National Reconnaissance Office appeared first on NASASpaceFlight.com .

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SpaceX will launch a pair of ocean surveillance satellites for the National Reconnaissance Office on Sunday for the NROL-85 mission. The satellite duo is slated for liftoff from Vandenberg Space Force Base at 6:13 AM PDT (13:13 UTC). A flight-proven Falcon 9 will be used to deliver the satellites into orbit, while the first stage returns to Vandenberg for a landing.



NRO Launch 85 (NROL-85) is the fourth dedicated Falcon 9 mission that SpaceX will carry out for the National Reconnaissance Office (NRO). The NRO is responsible for operating the United States fleet of intelligence-gathering satellites. Like most NRO missions, many details of Sundays launch and its payload are classified information.

SpaceX carried out its first mission for the NRO with the NROL-76 launch in May 2017 , which was the thirty-third flight of Falcon 9 overall and the
first time the rocket had flown for the US military. The NROL-108 launch followed in December 2020, with SpaceXs most recent mission from the agency being NROL-87 in February this year .

The NROL-85 mission is unusual in that the launchs target orbit has been published in advance. Normally this information is considered highly
sensitive and remains classified. However, when the US Air Force put the launch contract out for bidding in 2018, an attachment to the request for proposals included the requirements for delivery of the satellites in terms
of orbital parameters and accuracy.

This called for a semi-major axis of 7,500.5 kilometers at an eccentricity of 0.0131, corresponding to a 1,024-by-1,220-kilometer deployment orbit. The document also gave the target inclination as 63.535 degrees inclination and
an argument of perigee of 190.0 degrees.



The accuracy requirements allow for a discrepancy of up to 9.2 kilometers in perigee altitude, 22.2 kilometers in apogee altitude, 0.15 degrees inclination, and 5.0 degrees argument of perigee.

Such an orbit is used by a constellation of NRO satellites codenamed
Intruder, part of a longer-running series known as the Naval Ocean Surveillance System (NOSS). Intruder satellites launch and operate in pairs, scouring the Earths oceans for radio transmissions which they then can triangulate to pinpoint the position of ships. These capabilities allow NOSS to keep track of foreign shipping, particularly the navies of potentially hostile nations. See Also NROL-85 Updates SpaceX Missions Section L2 SpaceX Section Click here to Join L2

NOSS grew out of an earlier program called Poppy, a partnership between the Naval Research Laboratory and the NRO on electronic signals intelligence (ELINT) satellites. Poppy spacecraft, launched in the late 1960s and early 1970s, served as pathfinders for the NOSS constellation before the first dedicated satellites were deployed from 1976 onwards.

These first-generation satellites were codenamed Parcae or White Cloud, and launched in groups of three on Atlas rockets initially converted missiles, and later the purpose-built Atlas-H with a small solid-fueled upper stage.

Nine groups of three satellites often referred to as triads by observers were launched between 1976 and 1984, with one of these lost in a 1980 launch failure. A series of second-generation satellites began to be launched in 1990, retaining the three-satellite arrangement. A Titan IV launches an NRO payload from SLC-4E at Vandenberg AFB on October 19, 2005. This same pad
later became Falcon 9s West Coast launch site and is where NROL-85 will lift off from. Credit: US Air Force

These were significantly larger, riding to orbit aboard Titan IV launch vehicles. Four second-generation triads were launched, with the third launch also suffering a failure. The final triad was launched in May 1996 by a Titan IV(403)A flying from Vandenberg Air Force Base.

Intruder satellites represent the programs third generation, which began with the NROL-13 mission in September 2001. Launched by an Atlas IIAS rocket out
of Vandenberg, the mission surprised experts watching the NROs spacecraft
when only two satellites were observed in orbit. While this led to initial speculation that a third satellite had failed to deploy, as the pattern was repeated on subsequent launches it became clear that the new spacecraft were designed to operate as pairs.

To date, eight pairs of these third-generation satellites have been deployed. Previous launches have used Atlas rockets: the first two pairs flying aboard the Atlas IIAS and the third aboard an Atlas IIIB. Later launches have used the Atlas V , mostly flying in its 401 configuration. While it is not yet clear whether the NROL-85 satellites will be another third-generation pair or mark the start of the next generation of NOSS satellites, Sundays launch will mark the first time NOSS spacecraft have flown on a Falcon 9. Each launch patch tells a story. For #NROL85 , 3 stars represent guidance, protection & allegiance. The tiger in the cats reflection demonstrates that while space
can be challenging, a determined attitude helps NRO go #AboveandBeyond to protect our nation. #attitudeiseverything pic.twitter.com/lfS8XULZa7

NRO (@NatReconOfc) April 3, 2022



Based on the pattern of previous launches, Intruder satellites are typically replaced after about ten years in orbit, although some older spacecraft may
be kept in service after their replacements reach orbit. There are currently two pairs of NOSS spacecraft that appear to be due for replacement: USA-229 was launched as NROL-34 in April 2011, while USA-238 was launched as NROL-36 in September 2012. NROL-85 appears to be targeting the same orbital plane as USA-238.

NROL-85 will ride to orbit just over eleven years after NROL-34, the mission that deployed USA-229. USA-229s launch was somewhat unusual in that it was
the only Intruder pair to use an Atlas V 411 rocket instead of the 401 configuration. This was believed to be to allow the satellites to be inserted into orbit with a single burn of the rockets upper stage after a mishap during the coast between two burns on the previous launch had left the NROs satellites in a slightly off-target but recoverable orbit.

Because USA-238 is a newer pair of Intruder satellites than USA-229, it is
not immediately clear why the newer spacecraft appear to be in line to be replaced first. This could be down to the health or operational status of the satellites, changes in the structure of the constellation, or other requirements determined by the NRO.

The NROL-85 mission will launch from Falcon 9s west coast home: Space Launch Complex 4E (SLC-4E) at the Vandenberg Space Force Base. NOSS launches usually take place from Vandenberg , although some have lifted off from Cape Canaveral. The choice of the launch site is driven mostly by launch pad availability. Falcon 9 lifts off from SLC-4E on Februarys NROL-87 mission (credit: Jack Beyer for NSF)

SLC-4E was originally built as part of the US Navys Point Arguello launch site, located to the south of Vandenberg Air Force Base on the Californian coast. Point Arguello was transferred to the Air Force and became part of an enlarged Vandenberg Air Force Base in 1964, shortly before the first rocket lifted off from what would become SLC-4E.

The pad was originally designated Point Arguello Launch Complex 2-4
(PALC-2-4) and catered to the Atlas-Agena rocket. During this time the pad began its long association with the National Reconnaissance Office: most of the Atlas rockets launched from it carried the agencys KH-7 Gambit reconnaissance satellites.

After being renamed SLC-4E in 1966, the pad hosted its final Atlas launch in 1967 before undergoing conversion for use by heavy-lift versions of the Titan III rocket. SLC-4E was used by the Titan IIID rocket in its 23D and stretched 34D configurations, followed by the Titan IV. SLC-4E was the site of the
final launch of a Titan rocket in October 2005, when the Titan IVB made its last flight. All of the Titan missions flown from SLC-4E supported NRO programs, including three previous NOSS launches on Titan IVA rockets during the constellations second generation.

With Titans retirement, SLC-4E fell into disuse and stood dormant until 2011. SpaceX began work to convert the facility for its Falcon 9 rocket,
demolishing the Titan-era service towers and renovating the site to suit its operations. The first Falcon 9 launch from SLC-4E took place in September
2013 with the CASSIOPE mission which also marked the debut of the rockets v1.1 configuration. Prior to the NROL-85 launch, 21 Falcon 9 vehicles had flown from the pad adding to its legacy of 27 Atlas and 41 Titan launches. Sundays launch will be the ninetieth mission to lift off from this historic pad.

As well as its launch pad at SLC-4E, SpaceX facilities at Vandenberg also include Landing Zone 4 (LZ-4) , which was built on the site of SLC-4Es sister pad, SLC-4W. Like SLC-4E, this was originally built as an Atlas-Agena launch pad before seeing service with the Titan IIIB and Titan II(23)G rockets. In its new role as LZ-4, it provides a landing area for Falcon 9s first stage on return-to-launch-site (RTLS) missions. Due to excessive upper level winds forecasted for Saturday, we are now targeting no earlier than Sunday, April
17 for Falcon 9s launch of NROL-85 from Vandenberg Space Force Base

SpaceX (@SpaceX) April 15, 2022



Falcon 9 is a partially-reusable rocket, with the first stage and payload fairing designed to be recovered and refurbished for multiple launches while the second stage is expended on every mission. Building on the experience SpaceX gained from its smaller Falcon 1 rocket, Falcon 9 made its debut
launch in June 2010 and underwent a number of early design iterations and refinements. These have produced one of the most capable, versatile, and reliable rockets in the world, with NROL-85 marking the 150th orbital launch of the Falcon 9 and Falcon Heavy family.

For Sundays launch, Falcon 9 will fly with a flight-proven first stage, B1071.2. It will be the second launch for this core, which was previously
used on the NROL-87 mission at the beginning of February. After propelling Falcons second stage and payload on the first leg of their journey, B1071 returned to Vandenberg Space Force Base and touched down at LZ-4. It is expected to make another return to LZ-4 during Sundays mission.

The Falcon 9 was integrated horizontally in SpaceXs hangar to the northeast
of the launch pad, before being moved into position and raised to the
vertical using the transporter-erector, or strongback. This structure
supports the vehicle for most of the countdown and provides umbilical connections to the upper stage and fairing.

Fueling of the Falcon 9 will begin thirty-five minutes ahead of liftoff, with the loading of RP-1 kerosene propellant into both stages and liquid oxygen (LOX) into the first stage getting underway. Second stage LOX loading will commence later in the countdown, at the T-16 minute mark. Falcons liquid oxygen tanks will continue to be topped off until the final minutes of the countdown, replacing the oxidizer that boils off. At approximately T-7 minutes, Falcon 9 will begin its engine chilldown to prepare the first stage engines for flight.

With just over four minutes remaining in the countdown, the clamp arms at the top of the strongback will open, the first step in the process of retracting the strongback to its launch position. With the arms open, the strongback
will be rotated away from the rocket. SLC-4Es strongback is of an older
design than those used at SpaceXs other launch pads and moves directly to its launch position at this point in the countdown instead of holding in an intermediate position until liftoff. Falcon 9 climbs towards orbit during Februarys NROL-87 mission (credit: Jack Beyer for NSF/L2)

The first stage is powered by nine Merlin-1D engines. At the T-3 second mark in the countdown, Falcons engine controller will command these to start, with the engines igniting shortly afterward. Liftoff will follow at T-0, with Falcon climbing away from SLC-4E to begin NROL-85s journey into space.

During the early stages of ascent, Falcon 9 will perform a roll maneuver and
a pitch over to put itself on the right trajectory to reach its planned 63.5-degree orbit. Flying southeast, it will pass through the area of maximum dynamic pressure max-Q about seventy seconds after liftoff. Falcon will reach the speed of sound, Mach 1, around the same time.

Booster 1071.2s nine engines will power Falcon 9 for a little over two
minutes and twenty seconds before shutting down. This event, called Main Engine Cutoff (MECO), will be followed about four seconds later by stage separation. Falcon 9s second stage will take over to continue the NROL-85 mission, while the booster begins its return to Earth.

The second stages single Merlin Vacuum (MVac) engine will ignite about seven seconds after separation. Early in the second stage burn the payload fairing, which protected the NROL-85 payload during its ascent through the atmosphere, will separate from the nose of the rocket. It is normal for NRO missions to enter a media blackout around this time, with further updates on the status
of second stage flight being limited to confirmation of launch success after spacecraft separation has been completed.

While the second stage continues towards orbit, B1071.2 will head back to Vandenberg Space Force Base. Shortly after stage separation, it will reorient itself and initiate a boostback burn, canceling out its downrange velocity
and putting it on course back toward Landing Zone 4. Once the boostback is complete, the booster will deploy its grid fins to help guide its descent as it passes back into the atmosphere. A short entry burn around six and a half minutes after liftoff will help to slow the stage as it re-enters.

Once the entry burn ends, the booster will make an unpowered descent towards the landing zone. As it approaches LZ-4, its center engine will restart for the landing burn, slowing it to a gentle touchdown on the landing pad. This
is expected to occur a little over eight minutes after liftoff. B1071 lands
at LZ-4 during its previous mission, NROL-87 (credit: Michael Baylor for NSF)

Falcons second staThe second stage will reach orbit around the same time the first stage lands, shutting down its engine in an event known as second-stage engine cutoff 1 (SECO-1). While the mission profile has not been announced, NROL-85 will most likely require two burns from the upper stage, with the first burn having placed it into an initial transfer orbit. After a coast phase, the MVac engine will restart for a short circularization burn at the orbits apogee. With this complete, the NROL-85 spacecraft will separate.

With spacecraft separation completed, Falcon 9s second stage will fire its engine one final time to deorbit itself, burning up in the atmosphere over
the Pacific Ocean at the end of the mission.

NROL-85 is SpaceXs fourteenth launch of 2022, lifting off a week after the previous Falcon 9 successfully launched Crew Dragon Endeavour on the Axiom-1 mission. The next Falcon 9 launch is expected to be another Crew Dragon mission, with the new capsule Freedom flying the Crew-4 mission to the International Space Station. This is currently slated to fly no earlier than next Saturday, April 23.

Sundays mission is the second of four launches currently planned this year
for the National Reconnaissance Office. The agencys next two launches are planned for July and August: an Atlas V from Cape Canaveral with the NROL-107 SILENTBARKER mission and a Delta IV Heavy from Vandenberg with NROL-91.

(Lead image: Falcon 9 vertical at SLC-4E prior to the launch of NROL-85. Credit: SpaceX)

The post Falcon 9 to launch NROL-85 mission for National Reconnaissance
Office appeared first on NASASpaceFlight.com .



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Link to news story:
https://www.nasaspaceflight.com/2022/04/falcon-9-nrol-85/


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