NROL-52 – Atlas V 421 (AV-075) – Канаверал SLC-41 – 15.10.2017 07:28 UTC

Автор che wi, 26.07.2017 09:05:31

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tnt22

Цитировать10/14/2017 08:25

This hold is being extended a few more minutes.

tnt22

Цитировать10/14/2017 08:31 GO for fueling

Console operators have reported READY status during the pre-fueling readiness poll. The ULA launch director also voiced her approval for moving forward with the countdown today.

The loading of nearly 66,000 gallons of cryogenic liquid oxygen and liquid hydrogen into the Atlas 5 rocket will be getting underway a short time from now.

tnt22

Цитировать10/14/2017 08:32 Countdown running again

T-minus 2 hours and counting! The launch countdown has resumed for today's flight of the Atlas 5 rocket to deploy the clandestine NROL-52 satellite for the National Reconnaissance Office.

Clocks have one more built-in hold planned at T-minus 4 minutes.

In the next couple of minutes, chilldown thermal conditioning of the mobile launch platform upon which the rocket stands will begin. This is meant to ease the shock on equipment when supercold cryogenic propellants start flowing into the rocket.

tnt22

#223
Цитировать10/14/2017 08:37 New T-

A new launch time is being coordinated for liftoff at 3:38 a.m. EDT (0738 GMT) from Cape Canaveral's Complex 41. The adjustment was required after the T-minus 2 hour hold was extended.

Clocks have one more built-in hold planned at T-minus 4 minutes. That hold is planned to last 6 minutes.
During that pause, the final "go" for launch will be given, weather permitting.
Цитировать ULA‏Подлинная учетная запись @ulalaunch 4 мин. назад

The team has established a new launch time of 3:38 a.m. ET. #AtlasV #NROL52

tnt22

Цитировать10/14/2017 08:40 Centaur LOX loading

Filling of the Centaur upper stage with about 4,150 gallons of liquid oxygen has begun at Cape Canaveral's Complex 41 following the thermal conditioning of the transfer pipes.

The liquid oxygen -- chilled to Minus-298 degrees F -- will be consumed during the launch by the Centaur's single RL10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown. The Centaur will perform the firings required to propel the NROL-52 spacecraft into the desired orbit today.

tnt22


tnt22

Цитировать10/14/2017 09:01

The chilldown conditioning of liquid hydrogen propellant lines at Complex 41 is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket. The Centaur holds about 12,300 gallons of the cryogenic propellant.

tnt22

Цитировать10/14/2017 09:04 Atlas LOX loading

The conditioning of the systems for the first stage liquid oxygen tank have been completed. And a "go" has been given to begin pumping supercold liquid oxygen into the Atlas 5's first stage.

The Common Core Booster stage's liquid oxygen tank is the largest tank to be filled today. It holds 48,800 gallons of cryogenic oxidizer for the RD-180 main engine.

tnt22

Цитировать10/14/2017 09:07

The Centaur liquid oxygen tank reached the 96 percent level. The topping off process is starting now.

tnt22

Цитировать10/14/2017 09:14

Centaur liquid oxygen tank has reached flight level.

tnt22

Цитировать10/14/2017 09:25 Centaur LH2 loading

Chilldown of the liquid hydrogen system has been accomplished. The launch team has received the "go" to begin filling the Centaur upper stage with the supercold fuel.

10/14/2017 09:26

The Centaur engine chilldown sequence is being initiated.

tnt22

Цитировать Spaceflight101 LIVE‏ @S101_Live 50 сек. назад

One hour to the target #NROL52 launch time of 7:38 UTC. #AtlasV tanking is on track as the count progresses. Weather is the item to watch...

tnt22

Цитировать Spaceflight101 LIVE‏ @S101_Live 52 сек. назад

Based on the launch trajectory, #NROL52 is headed into Geostationary Transfer Orbit & the LV config suggests a close repeat of NROL-61.

tnt22

http://spaceflight101.com/atlas-v-nrol-52/nrol-52-satellite/
Цитировать
Identifying the classified NROL-52 Satellite
NROL-52 can be identified with a fairly high degree of certainty as belonging to the fourth generation of the classified Space Data System operated by the U.S. National Reconnaissance Office to relay data fr om U.S. intelligence-gathering assets in real time, including image reconnaissance data collected by the Keyhole satellites in elliptical polar orbits.
Спойлер

NROL-52 Mission Patch – Image: NRO

The Space Data System, in addition to relaying data to and fr om a variety of satellites, also supports the Air Force Satellite Control Network by connecting ground stations and also provides communications relay to Air Force aircraft on polar routes.

The NRO is an intelligence agency tasked with the design, construction and operation of all U.S. reconnaissance satellites as well as the distribution of satellite intelligence to other agencies including signals intelligence for the NSA, image reconnaissance to the NGA and measurement and signatures intelligence to the DIA. Established back in 1961, the NRO is shrouded in great secrecy and most of its active programs are highly classified with declassification only possible decades after the end of specific programs.


Atlas V with NROL-61 – Photo: United Launch Alliance

As an intelligence agency, the NRO makes great efforts to keep its activities secret, therefore the identity of any and all NRO satellites are classified. However, it is possible to identify the nature of satellites by analyzing their launch trajectory as available in navigational warnings to mariners and pilots, the type of launch vehicle to constrain an approximate satellite mass and the launch window to assess possible target orbits.

Typically, NRO satellites are tracked in their secret orbits within a few days by a worldwide network of satellite observers, revealing from wh ere they operate which usually provides a good idea of a satellite's purpose.

The case for NROL-52 appears straightforward since the mission is a close repeat of the 2016 NROL-61 mission that launched out of Cape Canaveral on an Atlas V 421 rocket and deployed the single payload into a Geostationary Transfer Orbit. That launch marked the first NRO use of the Atlas V 421 variant with a pair of Solid Rocket Boosters and an Extra-Extended Payload Fairing.

NROL-61 had already been suspected to belong to a new generation of the Satellite Data System based on the typical launch cadence for SDS and the apparent change to a more-powerful rocket from the Atlas V 401 used for the previous SDS missions suggested the new satellite generation was heavier. Tracking of the NROL-61 satellite confirmed it maneuvered into a Geostationary Orbit from wh ere SDS is known to operate.


Declassified Image of Early SDS Satellite – Credit: National Reconnaissance Office

Similarities between NROL-61 and 52 are the type of launch vehicle, not used in any other NRO program, the launch site, and the expected ascent trajectory – though final confirmation of the satellite's identity will come after launch once orbital parameters can rule out the possibility of a one-off mission.

The Satellite Data System, also known by its code name Quasar, saw its first launch in 1976 using a Titan-3 rocket. The first generation satellites – at least seven of which were launched until 1987 – weighed in at under one metric ton and operated from a Molniya-type orbit with their apogee locked over the northern hemisphere to enable data relay from the polar regions.

In addition to satellite data relay, the SDS craft support communications to U.S. Air Force aircraft in the northern regions and connect the Air Force Satellite Control Network ground stations.

The second generation of Quasar satellites was inaugurated in 1989 – Three second generation satellites were launched on the Space Shuttle while the last one, lofted in 1996, used a Titan-4 rocket. It is believed that the second generation SDS carried an infrared early warning system for the detection of ballistic missile launches with the satellites weighing in at around three metric tons. Three of the SDS-2 satellites were delivered to Molniya-type orbits with a 39,700-Kilometer apogee while one entered a Geostationary Orbit.


Molniya Orbit – Image: NASA


NROL-61 Initial Orbit – Image: Spaceflight101 / JSatTrak

The third generation of SDS satellites incorporates a combination of satellites in highly elliptical Molniya orbits for coverage of the northern regions and spacecraft in Geostationary Orbit to deliver round-the-clock global coverage

The replenishment of Molniya satellites apparently ended in 2007, likely marking the transition to a purely GEO-based system. Improvements in technology have allowed GEO satellites to service high-latitude regions, though polar coverage is still a challenge when only using satellites in GEO.

Eight third generation SDS satellites were launched between 1998 and 2014 with a launch cadence of around two to three years to keep the constellation at operational strength. The satellites used Atlas-IIAS, Atlas-V 401 and Delta IV M+(4,2) launch vehicles.

The use of the more-powerful Atlas V 421 indicates the next generation of SDS satellites, to which NROL-61 and 52 are believed to belong, has gained mass compared to their predecessors that used Atlas V vehicles without any boosters. Based on the injection orbit of NROL-61 and the known performance of Atlas V 421, it becomes clear that the SDS-4 generation may weigh up to around 5.1 metric tons per satellite.

Previous SDS launches utilized the Long Payload Fairing of the Atlas V rocket measuring 12 meters in length while the NROL-61 and 52 missions employed the 13.8-meter Extra-Extended Fairing, suggesting the next generation of SDS satellites requires more space inside the fairing, most likely for more or larger communications antennas.

A worldwide network of satellite trackers will attempt to spot the NROL-52 satellite after launch and track its climb into Geostationary Orbit and possible moves it will make to enter its operational spot above the Earth to provide further proof of the satellite's identity.
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tnt22

Цитировать Spaceflight101 LIVE‏ @S101_Live 1 мин. назад

Command Receiver/Decoder Testing is repeated at this point to ensure the Flight Termination System can receive destruct commands.

tnt22




tnt22

Цитировать10/14/2017 10:10 Waiting on the weather

Current weather conditions are observed NO GO due to the violation to the cumulus cloud criteria. Meteorologists are tracking the weather coming off the Atlantic in hopes conditions will become GO within today's launch opportunity. The odds are 80 percent NO GO.