NASA is set to resume a space science mission in October after suffering multiple technical problems with the intended Pegasus rocket.
Particularly, the space science mission is named the Ionospheric Connection Explorer or ICON, which intends to send a satellite to conduct further research on the Earth’s ionospheric area.
The ionosphere is of particular interest to researchers because it is in an area composed of ions and electrons, and the reflection is due to the interaction of the electrons with the electromagnetic fields of the radio waves.
The first knowledge of the ionosphere was based on the radio sounding of the upper atmosphere. But the waves emitted from the ground arrive only at a certain height because they cannot go beyond the “reflection peak” of the ionosphere, the layer located at about 300 km, where the electron density is maximum.
NASA intends to send the 288-kilogram ICON satellite to observe the interaction between terrestrial and space weather in the upper atmosphere. Studying that interaction can help scientists better predict the impacts of space weather phenomena.
Also, ICON carries scientific instruments which can study plasma waves in the ionosphere, a layer in the upper atmosphere where colorful auroras are generated. Changes in the ionosphere can also affect communications and navigation signals coming from satellites.
For now, the NASA and Northrop Grumman teams are doing the final stages of the mission before launch, which 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 a statement distributed Sept. 9, NASA said it was now targeting an Oct. 10 launch of the Ionospheric Connection Explorer (ICON) satellite from Cape Canaveral Air Force Station in Florida. The launch vehicle and satellite will be ferried from California to Florida on Northrop Grumman’s L-1011 carrier aircraft Oct. 1.
“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.”
Notably, the mission was grounded for nearly two years by problems with its Pegasus rocket.
ICON was originally scheduled to launch in late 2017 from Kwajalein Atoll in the Pacific, however, scientists and engineers identified issues with the rocket’s separation system which led them to delay the mission to June 2018.
While en route to Kwajalein for the June 2018 launch, engineers detected “off-nominal” data from the rocket, prompting a return to California and further delaying the mission to a November 2018 date. However, after the rocket’s L-1011 aircraft took off for a Nov. 7 launch attempt, engineers again detected off-nominal data from the rocket, which called for another delay.
By then, NASA announced that it will be moving the launch of the ICON mission to Cape Canaveral because of improved range access.
NASA and Northrop Grumman have failed to disclose details regarding the persistent technical difficulties but NASA has said that in a joint investigation with Northrop, they found that “a Pegasus sensor reading that was not within normal limits,” but didn’t discuss what part of the vehicle that sensor was associated with.
“The cause of the issue is understood, and the flight hardware has been modified to address the issue,” NASA said.
NASA also said that Northrop Grumman conducted two L-1011 test flights with the Pegasus “to verify the effectiveness of the modification.” The test flights revealed no issues.
The scheduled launch time for ICON is 9:30 p.m. EDT on Oct. 10 (0130 GMT on Oct. 11).
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.
The launch is the only Pegasus mission on Northrop Grumman’s manifest for the small rocket, which has flown only infrequently: three times in the last decade, most recently in December 2016. Despite the growing interest in small satellites, the high cost of the Pegasus has prevented it from winning additional business.