The aurora problem
To look for the solution, scientists would have to mimic nature — 250 miles up
Another question we receive pretty frequently is about this being the final night of the window and why exactly is that the case. ‘Why can’t you just keep trying?’ The challenge we are experiencing now if we continue going is that the moon is actually too far above the horizon and the principal investigator and his team will no longer be able to see the barium vapors, which is a key part of the mission.
THE "AURORA PROBLEM," as it is sometimes called, occurs at the smallest of scales and is vastly more complex than the simple statement that an aurora forms from the interaction of the solar wind with Earth’s magnetic field.
“I like to avoid saying there's a one-to-one connection between the solar wind and the aurora,” Delamere said. “There's a multi-step process of electron acceleration to get there. If you go through this multi-step process, eventually you get into the inner magnetosphere region where the aurora exists.”
In trying to solve that aurora problem, Delamere and colleagues at UAF and NASA wanted to use barium to create a controlled microenvironment in Earth’s far upper atmosphere similar to that existing when the solar wind hits Earth’s protective magnetic field, which deflects most of those solar particles. Observing a natural occurrence from a spacecraft is unrealistic because those occurrences are localized and dynamic, requiring an unlikely chance encounter with the spacecraft.
The KiNET-X payload being assembled. NASA photo by Berit Bland
Delamere and his collaborators first proposed the experiment to NASA in 2001, drawing in particular on three high-altitude experiments from 1986, 1989 and 1999.
Two, known as CRIT I and CRIT II, were rocket-based missions launched from NASA’s Wallops facility to investigate the phenomenon of critical ionization velocity in a realistic space environment.
Critical ionization velocity, proposed by Swedish physicist Hannes Alfvén in the 1950s, suggests that a neutral gas moving through a magnetized plasma will spontaneously ionize if its velocity relative to the plasma exceeds a specific threshold. Results of CIV experiments have been mixed, leaving the concept short of being conclusively proved.
The third experiment, called North Star I, was part of the Active Plasma Experiment program, or APEX, a joint U.S.-Russian effort funded by the Defense Department through its Ballistic Missile Defense Organization, now known as the Missile Defense Agency.
A portion of the front page of an April 1999 edition of Inside Missile Defense. (Alaska rocket launch article highlited by UAF editor.)
APEX North Star launched from the Geophysical Institute’s Poker Flat Research Range north of Fairbanks.
APEX was created “to promote U.S. and Russian scientific and technical cooperation through the joint study of the space environment effects of a high-speed, high-energy plasma,” according to an April 1999 article about the North Star launch in Inside Missile Defense magazine.
Although APEX North Star was a Defense Department experiment, the rocket did carry some civilian instruments.
“We were trying to piggyback science off of that Defense Department experiment,” said Delamere, who produced a 2004 paper about North Star while a research associate at the University of Colorado, Boulder.
That mission wasn’t ideal for learning about the dancing aurora, however.
A look inside one of the KiNET-X mission payloads. The rocket will carry seven separable payloads. NASA photo by Berit Bland
“The science team from APEX sat down in the aftermath of that project and on the back of a napkin sketched out an alternative design for such an experiment to enhance the science component,” said Delamere, who as a 1998 UAF Ph.D. graduate was on the APEX team as a postdoctoral researcher.
They proposed an experiment that would build on the APEX and CRIT missions but be of a fundamentally different design and have different scientific objectives.
NASA rejected it and then turned it down again a year later.
And so it sat for about 15 years until Delamere, who had turned his attention to the study of Jupiter and Saturn and their own auroras, met two APEX science team members at a 2017 Poker Flat launch.
They asked him to resurrect the proposal and pitched a new name: Kinetic-scale Energy and momentum Transport experiment, or KiNET-X.
KiNET-X would have similarities with APEX and other previous experiments: injection of plasma into Earth’s magnetic field to study the resulting interactions, including how plasma moves along magnetic field lines, how it interacts with background plasma and the role of plasma waves and instabilities. It differed in how the plasma was injected, in the material used and where the payloads were ejected.
“Maybe it was the name that sold it,” Delamere said. “It was funded the next year, and we went into design mode in 2018.”
NEXT: Part 4, Making waves
Top of page photo by Berit Bland, NASA
