CYGNSS (x8) – Pegasus XL – Канаверал, L-1011 Stargazer – 15.12.2016 13:35 UTC

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Chris B - NSF ‏@NASASpaceflight  7 мин.7 минут назад  
Chase plane views of Pegasus:
 
 
 
  Chris B - NSF ‏@NASASpaceflight  14 мин.14 минут назад  
Stargazer and Pegasus entering the racetrack over the Atlantic.
 

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Spaceflight Now ‏@SpaceflightNow  2 мин.2 минуты назад  
The Pegasus countdown runs with humans in the loop. Three controllers sit here aboard the L-1011 carrier jet. http://spaceflightnow.com/2016/12/12/cygnss-mission-status-center/ ...
 

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http://spaceflightnow.com/2016/12/12/pegasus-xl-launch-timeline-with-nasas-cygnss-microsats/

Pegasus XL launch timeline with NASA's CYGNSS microsats             
 December 12, 2016 Stephen Clark
 
Orbital ATK's Pegasus XL rocket will take about eight minutes to reach orbit with NASA's eight CYGNSS weather research microsatellites, then comes deployment of the spacecraft more than 300 miles (500 kilometers) above Earth.
The 51,000-pound (23-metric ton) rocket will drop from the belly of a modified L-1011 carrier plane, named Stargazer, flying on an east-southeast path over the Atlantic Ocean at an altitude of 39,000 feet (11,900 meters).
The Pegasus rocket, launching on its 43rd orbital mission, will fire three solid-fueled stages in succession, then release the eight Cyclone Global Navigation Satellite System spacecraft two at a time.
The images below were recorded from a previous flight.

Data source: NASA/Orbital ATK
T-00:00: Pegasus Drop
 
The 55-foot-long Pegasus XL rocket is released from the Orbital Carrier Aircraft off the east coast of Florida at an altitude of 39,000 feet above the Atlantic Ocean and a speed of Mach 0.82.

T+00:05: First Stage Ignition
 
After falling for five seconds to a distance of about 300 feet below the L-1011, the first stage Orion 50S XL solid-fueled motor of Pegasus is ignited to begin the powered journey to orbit with CYGNSS. Between drop and ignition, the Pegasus XL's destruct system is armed.

T+00:36: Max-Q
 
The Pegasus XL flies through the phase of maximum aerodynamic pressure, and the Orion 50S XL continues firing, reaching a peak power level of about 163,000 pounds of thrust.

T+01:17: First Stage Burnout
 
The Orion 50S XL first stage motor consumes all of its solid-fuel propellant and burns out at an altitude of more than 175,000 feet, or 53.5 kilometers.

T+01:33: First Stage Separation/Second Stage Ignition
 
The spent first stage motor is jettisoned at T+plus 1 minute, 33 seconds, to prepare for the second stage of flight. The first stage casing falls into the Atlantic Ocean. One second later, Orion 50 XL motor ignites at an altitude of 233,000 feet (71 kilometers) to continue the flight into orbit.

T+02:12: Fairing Jettison
 
The 50-inch-diamter (1.3-meter) payload fairing that protected the CYGNSS satellites during atmospheric ascent is separated once heating levels drop to predetermined limits. The second stage motor continues its burn with 44,000 pounds of thrust.

T+02:48: Second Stage Burnout
 
The Orion 50 XL second stage motor consumes all its solid fuel, then begins a four-minute coast phase for the rocket to climb to the targeted altitude for the CYGNSS mission. During this time, the rocket's on-board computer calculates when it needs to ignite the third stage based on the performance of the booster to this point.
 
T+06:37: Second Stage Separation
 
The Pegasus XL's second stage separates from the third stage.

T+06:48: Third Stage Ignition
 
 
The Pegasus XL's third stage Orion 38 motor fires for a planned 68-second burn to accelerate the eight CYGNSS microsatellites to orbital velocity.

T+07:56: Third Stage Burnout
 
The third stage Orion 38 solid-fueled motor burns out. The mission is targeting a circular orbit 317 miles (510 kilometers) above Earth at an inclination of 35 degrees.

T+12:56: Begin CYGNSS Spacecraft Deployments
 
The attitude control thrusters on the Pegasus XL's third stage will re-orient the vehicle for the deployment of the eight CYGNSS microsatellites, which will separate in pairs at T+plus 12 minutes, 56 seconds, T+plus 13 minutes, 26 seconds, T+plus 13 minutes, 56 seconds, and T+plus 14 minutes, 26 seconds. A ground station in Kourou, French Guiana, will be monitoring the separation events.

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Jeff Foust ‏@jeff_foust  6 мин.6 минут назад  
Range is now no-go for #CYGNSS launch because of anvil clouds. Expected to clear about 10 minutes before scheduled drop time.

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15:19

Now 20 minutes from the planned launch time. Today marks the 43rd flight of the air-launched Pegasus rocket and the 33rd using the XL version. The rocket weighs 51,000 pounds, stretches 55 feet long and is comprised of three solid-fueled stages for boosting small satellites into space.
The first stage is 33.7 feet long, 4.2 feet in diameter, has a wingspan of 22 feet and produces 163,000 pounds of thrust. The second stage is 4.2 feet long and 4.2 feet wide for 44,000 pounds of thrust. The third stage is 4.4 feet long and 3.2 feet in diameter with a thrust of 8,000 pounds.

15:16

The launch weather rule for attached anvil clouds is currently observed "no go," but the condition is expected to clear around 8:30 a.m. EST (1330 GMT), in time for a target drop time of 8:40 a.m. EST (1340 GMT).

[che wi]

Какие-то проблемы с гидравликой на самолете.

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Chris B - NSF ‏@NASASpaceflight  1 мин.1 минуту назад  
Working a hydraulics issue with the Pegasus. FTS arm check is complete, but they need to clear this issue.
 

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15:28
The Pegasus launch team is discussing an issue with a hydraulic pump.

15:22
The CYGNSS spacecraft have been transitioned to their own internal power, and the launch team reports they are go to transition the Pegasus rocket's destruct system to internal power at this point in the countdown.

15:21
The eight CYGNSS spacecraft inside the Pegasus rocket's fairing are reported ready to transition to internal power.

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Spaceflight Now ‏@SpaceflightNow  3 мин.3 минуты назад  
Pegasus launch team discussing an issue with a hydraulic system. Impact on 8:40am EST launch time unclear. http://spaceflightnow.com/2016/12/12/cygnss-mission-status-center/ ...
 

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Spaceflight Now ‏@SpaceflightNow  33 сек.33 секунды назад  
First Pegasus launch opportunity aborted for today. Launch team discussing whether another try can be made today. http://spaceflightnow.com/2016/12/12/cygnss-mission-status-center/ ...
 

[che wi]

1-ю попытку пуска отменили.

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Jeff Foust ‏@jeff_foust  1 мин.1 минуту назад  
This launch attempt has been aborted. #CYGNSS
 
  Jeff Foust ‏@jeff_foust  3 мин.3 минуты назад  
Range is still no-go for launch because of weather; there appears to be an alternate path clear of clouds, though. #CYGNSS

[che wi]

Orbital ATK ‏@OrbitalATK  1 minute ago

We are aborting for this pass. We will perform a recycle launch path. Weather is red in the drop zone #Pegasus #CYGNSS

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Jeff Foust ‏@jeff_foust  23 сек.23 секунды назад  
Still working a hydraulic pump issue and weather concerns; could try again before launch window closes at 9:19 am EST. #CYGNSS

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Chris B - NSF ‏@NASASpaceflight  2 мин.2 минуты назад  
Abort attempt 1: Stargazer carries a hydraulic system dedicated to the release mechanism. It's not the rocket, it's the release mech.
 

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Chris B - NSF ‏@NASASpaceflight  2 мин.2 минуты назад  
Troubleshooting step: Send someone into the galley and pull a plug. I'll do it! - Oh, they've already tried that.
 

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15:39
A preliminary target drop time of 9:05 a.m. EST (1405 GMT) has been scheduled, pending resolution of the hydraulic pump concern.

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Jeff Foust ‏@jeff_foust  39 сек.40 секунд назад  
Still working on the pump, but no progress, even when they "beat" on it. New drop time of 9:05 a.m. EST. #CYGNSS

[che wi]

2-я попытка: 1405 UTC / 1705 MSK

Orbital ATK ‏@OrbitalATK  7 seconds ago

Planning recycle and subsequent launch attempt to 9:05 am EST #Pegasus #Stargazer #Stargazer