Pegasus rocket aims to launch NASA weather satellite, from aircraft, into space
By RICHARD TRIBOU | Orlando Sentinel | Published: October 8, 2019
(Tribune News Service) — NASA wants a closer look at the zone where Earth weather meets space weather, and to do it, a satellite is launching sideways.
NASA will attempt to send the Ionospheric Connection Explorer satellite, or ICON, into space on board a Northrop Grumman Pegasus XL rocket launched from the company’s L-1011 Stargazer aircraft taking off from Cape Canaveral Air Force Station on Thursday night after delaying the planned Wednesday launch because of weather.
As opposed to a traditional vertical liftoff from the ground, NASA is using the aircraft-assisted launch, in which the Stargazer will take off from Cape Canaveral at around 8:32 p.m. and head for a location about 100 miles east of Daytona Beach at an altitude of 39,000 feet for a 9:30 p.m. launch attempt of the three-stage rocket.
The use of the aircraft-assisted rockets allows for minimal ground support and can get payloads under 1,000 pounds into space within 10 minutes. ICON weighs 634 pounds and is headed for an orbit in Earth’s ionosphere, 357 miles above. In comparison, the International Space Station orbits at about 220 miles above Earth.
The launch has actually been delayed from 2017, with its most recent attempt from Cape Canaveral in November 2018. Issues with the Pegasus rocket forced the aircraft and payload back to California for troubleshooting. The Stargazer returned to Cape Canaveral on Oct 1 and will give it another go during the 90-minute window Thursday.
The Air Force 45th Space Wing on Thursday gave the launch a 70 percent chance of favorable weather conditions with primary concerns of cumulus clouds and precipitation. A backup attempt window on Friday has a 90 percent chance of favorable weather.
NASA will live stream the launch starting at 9:15 p.m. at www.nasa.gov/live.
ICON looks to study the zone in which Earth’s weather interacts with space weather. This is the same area where the planet’s green-glowing auroras occur.
It’s also a zone in which the planet’s communications and GPS satellites have to pass through to service the human population below. Because of the torrid interaction of solar radiation and terrestrial winds high above the Earth, this zone can often lead to disruptions in service.
ICON wants to unwrap the complicated interaction happening in this upper atmosphere including analyzing the mix of charged particles and neutral atmospheric particles shaped by weather patterns closer to Earth’s surface, but doing it by orbiting right in the mix of the space.
In 2018, another NASA mission launched to a much higher location to take a look at the same area. Run by researchers out of the University of Central Florida, NASA’s GOLD mission was an 80-pound instrument that hitched a ride on a commercial satellite for an orbit of 22,000 miles above Earth.
GOLD stands for Global-scale Observations of the Limb and Disk, and it’s been gathering data with a goal of better predicting space weather events like solar flares.
“The upper atmosphere is far more variable than previously imagined, but we don’t understand the interactions between all the factors involved,” said Richard Eastes, GOLD principal investigator and researcher at the Florida Space Institute at the University of Central Florida in 2018. “The mission gives us the big picture of how different drivers meet and influence each other.”
ICON looks to dive deeper into that picture.
“To study hurricanes, we might use a weather satellite to track how they’re moving across the ocean, but to get detailed information, we fly a plane through the storm,” said Scott England, ICON project scientist based at Virginia Tech in Blacksburg, Virginia. “GOLD is like the weather satellite, and ICON is like the airplane.”
To achieve its goals, ICON includes an arsenal of four instruments. Three of them look at a phenomena called airglow, the same process that creates the Aurora Borealis and other Earth auroras, but actually happens all around the globe. It’s the process when gas gets excited and emits light. ICON will gather data on temperature, velocity and composition of gases miles away from the spacecraft, while the fourth measuring tool will look at the gases of the immediate ionosphere that the satellite is moving through.
The satellite’s strength is combining all of this data at the same time for researchers to use as opposed to using it from multiple sources and from multiple time periods.
“The unique thing is the suite of instruments,” said Ellen Taylor, ICON project systems engineer at UC Berkeley. “ICON has several instruments that have been flown before, but they’re put together into a payload suite to make unique measurements.”