ICON – Pegasus XL – Cape Canaveral AFS, L-1011 "Stargazer" – 11.10.2019 – 04:59:05 ДМВ

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https://spaceflightnow.com/2018/11/06/launch-timeline-for-pegasus-launch-of-icon-satellite/

Timeline for Pegasus launch of ICON satellite
November 6, 2018 | Stephen Clark

Northrop Grumman's Pegasus XL rocket will take about 11 minutes to place NASA's Ionospheric Connection Explorer, or ICON, satellite into a roughly 357-mile-high (575-kilometer) orbit after an airborne launch off Florida's east coast.

The nearly 53,000-pound (24-metric ton) rocket will drop from the belly of a modified L-1011 carrier plane, named Stargazer, flying on an easterly path over the Atlantic Ocean at an altitude of 39,000 feet (11,900 meters).

The Pegasus rocket, launching on its 44th orbital mission, will fire three solid-fueled stages in succession, then release NASA's ICON satellite into orbit to begin a mission studying how weather in Earth's atmosphere influences plasma conditions at the edge of space in the ionosphere, a boundary that can interfere with radio communications and satellite navigation.

The images below were recorded from a previous flight.

Спойлер

Data source: NASA/Northrop Grumman

T-00:00: Pegasus Drop


The 57-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 ICON. 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 177,000 feet, or 53.9 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 237,000 feet (72.1 kilometers) to continue the flight into orbit.

T+02:10: Fairing Jettison


The 50-inch-diamter (1.3-meter) payload fairing that protected the ICON during atmospheric ascent is separated once heating levels drop to predetermined limits at an altitude of around 381,000 feet (116 kilometers). 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 ICON 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+07:00: Second Stage Separation


The Pegasus XL's second stage separates from the third stage.

T+07:11: Third Stage Ignition


The Pegasus XL's third stage Orion 38 motor fires for a planned 69-second burn to accelerate the ICON satellite to orbital velocity.

T+08:20: Third Stage Burnout


The third stage Orion 38 solid-fueled motor burns out. The mission is targeting a circular orbit 357 miles (575 kilometers) above Earth at an inclination of 27 degrees.

T+11:20: ICON Separation


The attitude control thrusters on the Pegasus XL's third stage will re-orient the vehicle for the deployment of the ICON satellite. The spacecraft is programmed to begin extending its solar panel within about 100 seconds of separation from the Pegasus third stage.

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11/07/2018 10:00 Stephen Clark

All stations reported a "go" for departure of the L-1011 carrier aircraft from Cape Canaveral Air Force Station, with Air Force, NASA and Northrop Grumman officials voicing approval for takeoff.

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11/07/2018 10:06 Stephen Clark

The L-1011 "Stargazer" carrier aircraft with the Northrop Grumman Pegasus XL rocket has departed Cape Canaveral Air Force Station in Florida for this morning's launch of NASA's ICON mission. The booster will be released from the jet over the Atlantic Ocean around 3:05 a.m. EST to propel the Ionospheric Connection Explorer into a 357-mile-high (575-kilometer) orbit.

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11/07/2018 10:39 Stephen Clark

ABORT. Today's launch attempt has been scrubbed.

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NASA_LSP‏Подлинная учетная запись @NASA_LSP 2 мин. назад

We have encountered an anomaly while ferrying the #PegasusXL for the launch of #NASAICON. The L-1011 is returning to base for investigation. The team is evaluating the next launch attempt.

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Chris B - NSF‏ @NASASpaceflight 9 мин. назад

ARTICLE:
NASA's ICON mission on Northrop Grumman Pegasus XL rocket scrubbed -

https://www.nasaspaceflight.com/2018/11/nasas-icon-launch-ngis-pegasus-xl-rocket/ ...

- By Chris Gebhardt (@ChrisG_NSF)

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Northrop Grumman‏Подлинная учетная запись @northropgrumman 13 мин. назад

.@NASA & #NorthropGrumman scrubbed today's launch of #PegasusXL due to off-nominal data received during the captive carry flight. The L-1011 Stargazer returned to CCAFS and the team will begin an investigation.
#NASAICON remains healthy & we are evaluating the next launch attempt

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Spaceflight Now‏ @SpaceflightNow 3 мин. назад

Northrop Grumman's rocket carrier aircraft has landed back at Cape Canaveral Air Force Station after this morning's scrubbed launch attempt. There's another launch opportunity Thursday if engineers resolve the technical concern on the Pegasus rocket.

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Ken Kremer‏ @ken_kremer 18 ч. назад

Have confirmed there will be NO #NASAICON launch attempt overnight tonight at 3 AM ET 11/8 on #PegasusXL air-launched rocket. NO new NET at this time as @northropgrumman & @Nasa team investigates/evaluates root cause continuing off nominal data signatures

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Chris B - NSF‏ @NASASpaceflight 27 мин. назад

Meanwhile, Stargazer, Pegasus and ICON appear to be preparing to head back to Vandenberg, so the ICON mission will be slipping a fair amount - and might, of course, be actually switching back to it's original West Coast launch as a result. We'll have to wait and see.

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https://blogs.nasa.gov/kennedy/2018/11/16/icon-to-return-to-vandenberg-afb-for-further-analysis/
https://blogs.nasa.gov/icon/2018/11/16/icon-to-return-to-vandenberg-afb-for-further-analysis/

ICON to Return to Vandenberg AFB for Further Analysis

Bob Granath
Posted Nov 16, 2018 at 12:28 pm

NASA and Northrop Grumman have made the decision to fly the L-1011 Stargazer and Pegasus XL rocket carrying NASA's Ionospheric Connection Explorer, or ICON, spacecraft back to its integration facility at Vandenberg Air Force Base in California. The ferry flight will take place early next week. Returning to the environmentally-controlled integration facility allows the team to further investigate off-nominal data observed during the Nov. 8 launch attempt.

Once the investigation is complete, a new launch date will be determined. ICON will launch out of Cape Canaveral Air Force Station in Florida. The ICON spacecraft, which uses Northrop Grumman's LEOStar-2 platform, is monitored at all times and remains healthy.

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https://blogs.nasa.gov/kennedy/2018/11/28/nasas-icon-analysis-underway-at-vandenberg-afb/
https://blogs.nasa.gov/icon/2018/11/28/nasas-icon-analysis-underway-at-vandenberg-afb/

NASA's ICON Analysis Underway at Vandenberg AFB

Bob Granath
Posted Nov 28, 2018 at 3:25 pm


This illustration depicts NASA's Ionospheric Connection Explorer, or ICON, satellite that will study the frontier of space: the dynamic zone high in our atmosphere where terrestrial weather from below meets space weather from above.
Photo credit: NASA

On Monday, Nov. 19, Northrop Grumman flew the L-1011 Stargazer and Pegasus XL rocket carrying NASA's Ionospheric Connection Explorer, or ICON, spacecraft back to Vandenberg Air Force Base in California. On Nov. 20, Northrop Grumman completed the de-mate of Pegasus from the L-1011 and transported the rocket safely into the integration facility.

The Northrop Grumman/NASA team continues its investigation into the off-nominal data observed during the Nov. 7 launch attempt. Once the analysis is complete, a new launch date will be determined. ICON will launch out of Cape Canaveral Air Force Station in Florida.

The ICON spacecraft, which uses Northrop Grumman's LEOStar-2 platform, is monitored at all times and remains healthy.

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Jeff Foust‏ @jeff_foust 46 мин. назад

Nicola Fox, heliophysics division director, says ICON launch on a Pegasus XL now scheduled for early 2019.

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@jeff_foust · 3 ч

At a National Academies committee meeting this morning, Nicky Fox, head of NASA's heliophysics division, says the ICON launch now planned for no earlier the 2nd quarter. Northrop Grumman still working "extremely hard" on problems with the Pegasus launch vehicle.

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Stephen Clark‏ @StephenClark1 21 мин. назад

Nicky Fox, head of NASA's heliophysics division, tells National Academy of Sciences committee that Northrop Grumman plans test flight of the Pegasus XL under its L-1011 carrier jet in a few weeks. If it goes well, launch campaign for long-delayed ICON satellite could soon follow.

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Jeff Foust‏ @jeff_foust 9 мин. назад

NASA's Bill Gerstenmaier speaking now at the ASEB/SSB meeting, with a broad overview of HEOMD programs. Notes problem with Pegasus XL that delayed ICON launch for months appears to have been solved; should be ready to launch this summer.

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https://www.flickr.com/photos/nasakennedy/48642896996/

NASA Kennedy

VAFB-20190810-PH_RNB02_0005
Technicians removed the solar array fr om NASA's Ionospheric Connection Explorer (ICON) during a deployment test inside Building 1555 at Vandenberg Air Force Base in California on Aug. 10, 2019. ICON is being prepared for its launch on a Pegasus XL rocket, attached beneath the company's L-1011 Stargazer aircraft. Launch is scheduled for Oct. 10, 2019, from the Skid Strip at Cape Canaveral Air Force Station in Florida. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere wh ere terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology and communications systems. Photo credit: NASA/Randy Beaudoin

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https://blogs.nasa.gov/icon/2019/09/06/icon-launch-targeted-for-oct-10/
https://blogs.nasa.gov/kennedy/2019/09/06/icon-launch-targeted-for-oct-10/

ICON Launch Targeted for Oct. 10

Anna Heiney
Posted Sep 6, 2019 at 12:23 pm


Technicians extend the solar array on NASA's Ionospheric Connection Explorer (ICON) during a deployment test inside Building 1555 at Vandenberg Air Force Base in California on Aug. 10, 2019. Photo credit: NASA/Randy Beaudoin

NASA and Northrop Grumman currently are preparing the agency's Ionospheric Connection Explorer, or ICON, spacecraft and the Pegasus XL rocket at Vandenberg Air Force Base in California for ferry to the Cape Canaveral Air Force Station in Florida by the L-1011 Stargazer aircraft on Oct. 1, 2019. The launch has been rescheduled to Oct. 10, 2019, following the completion of a joint NASA/Northrop Grumman investigation into a Pegasus sensor reading that was not within normal limits during previous ferry and launch attempt flights. The cause of the issue is understood, and the flight hardware has been modified to address the issue. Two L-1011 flights with Pegasus were conducted to verify the effectiveness of the modification with no issues. Functional tests are being performed on NASA's ICON spacecraft, which utilizes Northrop Grumman's LEOStar-2 platform, to ensure that the ICON spacecraft is ready for the upcoming integration activity, ferry flight and launch. As always, mission success for Pegasus and ICON is the top priority.

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https://spaceflightnow.com/2019/09/10/long-delayed-nasa-science-satellite-gets-october-launch-date/

Long-delayed NASA science satellite gets October launch date
September 10, 2019 | Stephen Clark


Technicians extend the solar array on NASA's Ionospheric Connection Explorer, or ICON, satellite during a deployment test Aug. 10 at Vandenberg Air Force Base, California. Credit: NASA/Randy Beaudoin

The launch of a NASA ionospheric research satellite off Florida's east coast is targeted for Oct. 10 after persistent technical problems with its air-dropped Pegasus rocket stymied two launch opportunities last year.

The launch campaign for the Ionospheric Connection Explorer, or ICON, mission resumed this week.

The first steps were expected to include electrically and mechanically connecting the 634-pound (288-kilogram) ICON spacecraft to the front end of its Northrop Grumman Pegasus XL launcher inside Building 1555 at Vandenberg Air Force Base, California.

In the coming weeks, ground teams inside Building 1555 will encapsulate the satellite inside the Pegasus nose fairing and ready the solid-fueled rocket for rollout to meet an L-1011 carrier jet at the Vandenberg airfield. Technicians will bolt the Pegasus under the belly of the L-1011 jet, which will ferry the rocket on a cross-country flight to Cape Canaveral Air Force Station on Oct. 1, according to NASA.

After final launch rehearsals and checkouts, the L-1011 will take off fr om the Skid Strip at Cape Canaveral and head to a predetermined drop box over the Atlantic Ocean around 100 miles (160 kilometers) east of Daytona Beach, where the flight crew will release the winged Pegasus launcher to ignite and fire into a 357-mile-high (575-kilometer) orbit with ICON.

The scheduled launch time for ICON is 9:30 p.m. EDT on Oct. 10 (0130 GMT on Oct. 11).
The scheduled launch time for ICON is 9:30 p.m. EDT on Oct. 9 (0130 GMT on Oct. 10). NASA previously set the target launch date for Oct. 10, but an earlier date became available on the Air Force-run Eastern Range.

The Pegasus and ICON teams have been through this twice before. Recurring problems in the Pegasus XL's electrical systems kept the mission grounded on two launch campaigns last year.

Engineers noticed unexpected readings from the Pegasus rocket's rudder during a ferry flight last June to the mission's original launch base on Kwajalein Atoll in the Pacific Ocean. Managers decided to return the rocket to Vandenberg during a planned stopover in Hawaii.

NASA and Northrop Grumman officials agreed to relocate the mission's staging base to Cape Canaveral in the aftermath of the aborted Kwajalein launch campaign. Launching from Florida was not originally planned because the ICON satellite was expected to be slightly heavier than it turned out to be, which would have required a launch from a location closer to the equator.

But similar rudder data signatures cropped up during a ferry flight from Vandenberg to Cape Canaveral last October, prompting more data reviews and hardware changes in an attempt to resolve the problem. Teams thought they might have the issue fixed, but telemetry data again showed a potential problem after the L-1011 and Pegasus departed Cape Canaveral toward the drop box for a launch attempt Nov. 7.

Managers ordered another stand-down to further investigate the problem, and NASA announced Friday that the mission has been rescheduled for Oct. 10.

"The launch has been rescheduled to Oct. 10, 2019, following the completion of a joint NASA/Northrop Grumman investigation into a Pegasus sensor reading that was not within normal limits during previous ferry and launch attempt flights," NASA said in a statement. "The cause of the issue is understood, and the flight hardware has been modified to address the issue."

NASA said Northrop Grumman conducted two L-1011 test flights with the Pegasus "to verify the effectiveness of the modification." The test flights revealed no issues.

Sources familiar with the launch preparations said engineers were not able to identify a root cause for the strange readings from the Pegasus rudder actuator, which is located on the rear of the three-stage rocket. Investigators traced the proximate cause of the data problems to the behavior of a potentiometer in a dynamic flight environment.

In addition to the hardware fix, engineers developed new software to filter out "rudder spikes" from poor data, one source said.

"Northrop Grumman thinks they've solved the problem," the source said. "They'll be monitoring with all eyes on the rudder."


A Northrop Grumman Pegasus XL rocket, carried underneath a modified L-1011 airplane, departs Vandenberg Air Force Base in California on June 6, 2018, on the way to Kwajalein Atoll in the Pacific Ocean. The rocket and carrier jet returned to Vandenberg two days later after engineers encountered a technical problem with the launch vehicle during the ferry flight. Credit: NASA/Randy Beaudoin

ICON carries scientific instruments to investigate plasma waves in the ionosphere, a layer in the upper atmosphere wh ere colorful auroras are generated. Changes in the ionosphere can also affect communications and navigation signals coming from satellites, and ICON will study how weather systems lower in the atmosphere can influence conditions at the edge of space.

ICON's ride into space has been delayed more than two years by concerns related to its Pegasus launcher.

Engineers wanted more time to inspect the Pegasus rocket motors after they were mishandled during shipment to Vandenberg. That pushed the launch back from June to December 2017, the next availability in the military-run range at Kwajalein in the Marshall Islands.

Then managers decided to ground the mission to assess the reliability of bolt-cutters used to jettison the Pegasus rocket's payload fairing and separate the satellite in orbit.

Those issues were closed out before the first ICON launch campaign last year, when the rudder problems first appeared.

The ICON mission will be the 44th launch of a Pegasus rocket on a satellite delivery mission, and the 34th in the Pegasus XL configuration with uprated solid rocket motors. It will be the seventh Pegasus launch based out of Cape Canaveral, which hosted the most recent Pegasus rocket mission in December 2016.

Northrop Grumman has no more Pegasus launches in its backlog after ICON.

A NASA satellite named the Imaging X-ray Polarimetry Explorer was designed to fly on a Pegasus rocket in 2021 into a unique equator-hugging orbit that would have typically required a launch from an equatorial launch site like Kwajalein, the remote staging point for four previous Pegasus missions, and ICON's original launch base.

But SpaceX won the IXPE launch contract, and plans to deliver the satellite into its unusual low-inclination orbit using a more powerful Falcon 9 rocket launched from the Kennedy Space Center in Florida.

Another Northrop Grumman customer, Stratolaunch, purchased parts for two Pegasus rockets to launch from the company's giant carrier aircraft, which flew for the first time in April. But those plans are in doubt after reports that the holding company Vulcan Inc., founded by the late billionaire Paul Allen, is seeking to sell Stratolaunch.

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