ICON w końcu na orbicie 11.10. o 00:31 z pasa 13/31 na Cape Canaveral wystartował samolot L-1011 "Stargazer". Podwieszona pod nim rakieta
Pegasus-XL została zrzucona o 01:59:00, a o 01:59:05 nastąpił zapłon silnika jej pierwszego stopnia. Rakieta wyniosła
w T+8' 20" na orbitę o parametrach: hp=569 km, ha=569 km, i=26,99° satelitę naukowego ICON (Ionospheric Connection
Explorer).
http://lk.astronautilus.pl/n191001.htm#04Pegasus launches ICON space science missionby Jeff Foust — October 11, 2019
A Northrop Grumman Pegasus XL rocket, attached to its L-1011 aircraft, prior to the launch of the ICON satellite Oct. 10. Credit: Northrop GrummanLAS CRUCES, N.M. — A long-delayed NASA space science satellite finally reached orbit Oct. 10 on a Pegasus rocket, a launch vehicle with an uncertain future.
The Pegasus XL rocket was released from its L-1011 carrier aircraft at 9:59 p.m. Eastern off the Florida coast and ignited its motors to ascend to orbit. Its payload, the Ionospheric Connection Explorer, or ICON, was released from the upper stage in low Earth orbit about 11 minutes after ignition.
NASA scheduled the launch for 9:30 p.m. Eastern but a communications glitch shortly before the planned release led to a half-hour delay. NASA scrubbed a launch attempt Oct. 9 hours before the plane’s takeoff from Cape Canaveral because of poor weather in the area.
Those delays, though, pale in comparison to issues with the Pegasus rocket that delayed its launch by about two years. That included a case where the rocket’s rudder position indicator became active, but only while the rocket was attached to the aircraft at cruise altitudes.
“We saw some things on our previous launch attempt that none of us were comfortable with, and we decided to stand down and go address those,” said Phil Joyce, vice president of space launch programs at Northrop Grumman Innovation Systems, at a pre-launch briefing Oct. 8. That previous launch attempt, also based out of Cape Canaveral, was in November 2018.
Joyce described the issue with the rocket as “one of the most challenging that I’ve seen.” He said the rudder on the rocket’s first stage showed “noise spikes” in its position indicator, only at altitude. “We didn’t understand those, but they were significant enough that we were concerned if, we launched with that condition present, that those noise spikes could couple into our control system and cause a bad day.”
He said that the problem could be linked to “several causal factors” that the company addressed by modifying electronics in the rocket as well as making a feedback circuit more robust to the environmental conditions of flight. That was tested on several captive carry flights, including a ferry flight from Vandenberg Air Force Base in California to Cape Canaveral, giving Northrop and NASA confidence they had resolved the problem.
The ICON launch was the 44th Pegasus mission in the rocket’s nearly three-decade history, but also only the fourth launch in the last 10 years. Despite the growing interest in small satellites, for which Pegasus was designed to launch, the vehicle has only been used in recent years for a handful of NASA science missions.
Even that limited business is now in jeopardy. In July, NASA awarded a contract to SpaceX for the Falcon 9 launch of the Imaging X-Ray Polarimetry Explorer (IXPE) astronomy mission, a smallsat that had been designed to be compatible with the Pegasus XL rocket. The value of the Falcon 9 IXPE contract was $50.2 million, less than the $56.4 million value of the 2014 contract NASA awarded for the ICON launch on a Pegasus XL, even though the Falcon 9 is a far larger vehicle.
At the pre-launch briefing, Joyce acknowledged that the company has no future missions on the Pegasus XL manifest. He did note there are two Pegasus rockets at Vandenberg “in a pretty advanced state of integration” that are available. “We’re talking to several potential customers for those,” he said.
Those two rockets, industry sources say, were being built for Stratolaunch, the venture backed by the late Paul Allen that planned to launch Pegasus rockets from the giant aircraft it developed. That plane flew a single test flight in April, but the lack of activity since has fueled speculation that the company may be winding down.
The 288-kilogram ICON satellite will study the interaction between space weather and terrestrial weather in the ionosphere that could improve modeling of space weather activity. “It’s this region where these two weather systems, space weather and terrestrial weather, are mixing together,” said Nicola Fox, director of NASA’s heliophysics division, at the Oct. 8 briefing. “It’s really, really important for us to go understand that.”
Despite the delays, Fox said that the mission remained with its cost cap of $252 million. NASA didn’t make major changes to ICON during the extended launch delay, but she said the mission should benefit from data from other, complementary missions collected during this time. “If anything,” she said, “we’re a little more excited about ICON is going to bring to us.”
https://spacenews.com/pegasus-launches-icon-space-science-mission/Timeline for Pegasus XL’s launch with NASA’s ICON satelliteOctober 9, 2019 Stephen Clark
https://spaceflightnow.com/2019/10/09/timeline-for-pegasus-xls-launch-with-nasas-icon-satellite/Pegasus rocket ready for airborne launch with NASA scientific satelliteOctober 8, 2019 Stephen Clark
A Northrop Grumman Pegasus XL rocket is mounted underneath an L-1011 carrier jet, which will fire the launcher into orbit as soon as Wednesday night off Florida’s east coast. Credit: NASA/ Ben Smegelsky(...) Two launch campaigns last year were cut short by erroneous data signatures that showed movement on the Pegasus rocket’s rudder, one of three aerodynamic control surfaces on the solid-fueled rocket’s winged first stage.
“It was the rudder actuator (where) we were seeing some anomalous position feedback readings, basically noise spikes in the feedback line,” said Phil Joyce, vice president of space launch programs at Northrop Grumman. We didn’t understand those, but they were significant enough that we were concerned that, if we launched with that condition present, those noise spikes could couple into our control system and cause a bad day.”
Engineers from Northrop Grumman and NASA spent 11 months analyzing the problem, testing hardware, developing corrective actions, and then preparing the Pegasus XL rocket and the ICON satellite for another try at launching. (...)
https://spaceflightnow.com/2019/10/08/pegasus-rocket-ready-for-airborne-launch-with-nasa-scientific-satellite/NASA satellite to study ionosphere launches after two-year delayOctober 11, 2019 Stephen Clark
Artist’s illustration of the Ionospheric Connection Explorer satellite. Credit: NASA(...) ICON will begin regular scientific observations in late November with a suite of four instruments.
“ICON has an important job to do – to help us understand the dynamic space environment near our home,” said Nicky Fox, director for heliophysics at NASA Headquarters in Washington. “ICON will be the first mission to simultaneously track what’s happening in Earth’s upper atmosphere and in space to see how the two interact, causing the kind of changes that can disrupt our communications systems.”
The launch of NASA’s ICON satellite was the 44th satellite delivery mission for the Pegasus rocket since its debut in 1990. Originally developed by Orbital Sciences Corp., now part of Northrop Grumman, the Pegasus rocket has accomplished 30 consecutive successful satellite launches with Thursday night’s mission.
But the future of the Pegasus rocket, once a workhorse for NASA’s small satellite programs, is unclear after the long-delayed ICON launch.
There are no more missions on the Pegasus rocket’s manifest, and a recent NASA launch contract that was expected to likely be awarded to Northrop Grumman for a Pegasus flight went to SpaceX instead.
The Pegasus is not competitive in the commercial launch market because of its high price, but Northrop Grumman, and its predecessor Orbital Sciences, found a niche market for the Pegasus in recent years to loft NASA satellites that needed dedicated launches into unique, mission-specific orbits.
Northrop Grumman has hardware in inventory for two more Pegasus XL rockets. Those vehicles were purchased by Stratolaunch, a company founded by the late Microsoft co-founder Paul Allen, to launch of its own giant rocket carrier aircraft. (...)
Like the Pegasus XL launcher, the ICON satellite was built by Northrop Grumman. It’s based on the company’s LEOStar 2 satellite bus.
The ICON mission will investigate the link between conditions in the ionosphere, which scientists long thought was primarily driven by solar activity, and weather deeper in Earth’s atmosphere.
“The ionosphere is the densest plasma in space between us and the sun, and that plasma has a number of effects on systems that we use every day,” said Thomas Immel, ICON’s principal investigator from the University of California, Berkeley.
Immel proposed the ICON mission to NASA, and the agency selected the ICON proposal for development in 2013.
The ICON mission will study “how weather in our lower atmosphere, the weather we experience from day to day, influences conditions in space,” Immel said. “This coupling of the lower atmosphere to the upper atmosphere is a new science topic for NASA.”
NASA’s ICON mission will orbit above the upper atmosphere, through the bottom edge of near-Earth space. Here it will be able to observe how interactions between terrestrial weather and a layer of charged particles called the ionosphere creates changes in the space environment — including bright swaths of color in the atmosphere called airglow.
Credits: NASA’s Goddard Space Flight Center/ICONPrevious satellite missions detected the unexpected coupling between plasma waves and winds in the ionosphere and terrestrial weather systems.
“What we discovered, using data from a NASA mission called IMAGE, was that this region of the upper atmosphere and ionosphere was actually responding to effects related to weather systems near Earth’s surface,” said Scott England, ICON project scientist based at Virginia Tech. “This was really unexpected at the time, to see a connection. Where the charged particles were, how many there were, how dense the gas was — they were responding to weather patterns near the surface of the Earth.”
“We saw with those missions that the density in the ionosphere varied in response to changes in the rainy seasons in the tropics,” Immel said. “The new mission of ICON is to focus on that topic, and we’re carrying the instruments to invesitgate that region.
“We think focusing on that will give us a real key to understanding and making better predictions for space weather,” he said.
ICON carries four types of instruments developed at the University of California, Berkeley, the Naval Research Laboratory, and the University of Texas at Dallas.
Another NASA mission named GOLD — short for Global-scale Observations of the Limb and Disk — has objectives that intersect with ICON’s planned observations.
GOLD is mounted on a geostationary satellite more than 22,000 miles (nearly 36,000 kilometers) over the equator, providing wide-area views of the airglow in the ionosphere.
“ICON is going to come along and provide those in situ measurements, flying right through some of those plasma bubbles that we’ve been imaging with GOLD for a year now,” Fox said.
If ICON had launched on its original schedule, it would have been in space before GOLD.
“There has been a two-year delay,” Fox said. “We have learned a little bit more science. We now have a year’s worth of GOLD images, so I think, if anything, we’re even more excited about what ICON is going to bring to us.”
https://spaceflightnow.com/2019/10/11/nasa-satellite-to-study-ionosphere-launches-after-two-year-delay/Rockets purchased by Stratolaunch back under Northrop Grumman controlOctober 10, 2019 Stephen Clark
File photo of a Pegasus XL rocket inside the Building 1555 processing facility at Vandenberg Air Force Base, California. Credit: NASA/Randy Beaudoin(...) The airborne launch of NASA’s Ionospheric Connection Explorer, or ICON, scientific satellite Thursday night off Florida’s east coast is the final scheduled flight of a Pegasus XL rocket. Variants of the solid-fueled Pegasus rocket have flown on 43 satellite delivery missions since 1990.
“We actually purchased those back (from Stratolaunch),” Joyce said in an interview with Spaceflight Now. “So they’re in a very advanced state of integration, which means they’re available for a very rapid response launch. We could launch one of those in six months, the second one probably in eight (months).
“We’ve been talking with NASA and several other customers about potential use of those for the near-term,” Joyce said. “There are some interesting opportunities.”
Orders of Pegasus rockets have tailed off over the last few years as new, lower-cost launch options become available to NASA, the sole Pegasus customer since 2008. Northrop Grumman’s rocket division, then known as Orbital Sciences, won a $56.3 million contract to launch the ICON mission in 2014. The launch has been delayed more than two years due to technical problems with the Pegasus rocket.
The Pegasus rocket is carried aloft by a modified L-1011 aircraft — the last of its kind still operational — to an altitude of 39,000 feet (11,900 meters), then released to fire into orbit.
The handover of the Pegasus rockets back to Northrop Grumman is another sign of a turbulent year at Statolaunch since Allen’s death last October. Stratolaunch is part of Vulcan Inc., a holding company established by Allen, a Microsoft co-founder.
https://spaceflightnow.com/2019/10/10/rockets-purchased-by-stratolaunch-back-under-northrop-grumman-control/https://www.nasaspaceflight.com/2019/10/nasas-icon-launch-ngis-pegasus-xl-rocket/https://news.northropgrumman.com/news/releases/northrop-grumman-successfully-launches-nasa-icon-satellite-on-pegasus-rockethttps://space.skyrocket.de/doc_sdat/explorer_icon.htm
Wątek: Starty rakiet (IV kwartał 2019 roku) (Przeczytany 37054 razy)