WASHINGTON — A team at NASA’s Marshall Space Flight Center is beating the bushes for a prime contractor on an extreme ultraviolet observatory it plans to propose for an Explorer-class competition set to begin in 2016.
The mission, which does not yet have a name, would be led by principal investigator Jonathan Cirtain, heliophysics team lead in the Heliophysics, Planetary and Space Weather Branch of the Space Sciences Office at Marshall in Huntsville, Ala.
The primary instruments for the spacecraft Cirtain’s team wants to build would be modeled after another experiment on which he was principal investigator: the 3-meter-long High resolution Coronal Imager (Hi-C) telescope that photographed the sun’s corona during a $5 million suborbital mission launched in July 2012 from the White Sands Missile Range in New Mexico.
NASA is expected to release an announcement of opportunity for the heliophysics-only Explorer mission in 2016 at the earliest. The mission would notionally launch between 2020 and 2022, according to a request for information posted online July 31.
The prime contractor Cirtain is seeking would have to provide a spacecraft bus and integration for the mission, which would study the sun’s corona using “one or two extreme ultraviolet telescopes modeled after our recent sounding rocket experiment,” Cirtain said in an Aug. 8 email.
When Hi-C flew in 2012, it took high-resolution photographs of the sun’s corona, the outer region of the solar system’s resident star where temperatures can reach 1.5 million degrees Kelvin. When the corona ejects some of its mass, the result is space weather — a potential hazard for satellites and people in space.
The telescope, built around a mirror 24 centimeters in diameter, was assembled by Smithsonian Astrophysical Observatory laboratory in Cambridge, Mass. The lab also worked on the mirror, which was originally developed at Marshall. L-3 Communications/Tinsley Laboratories of Richmond, Calif., and Reflective X-ray Optics of New York also contributed to the mirror.
Cirtain said Hi-C might fly again as soon as 2015.
As part of the proof-of-concept work for the Explorer proposal, “we will modify the payload from White Sands for a few new technology tests and then use the outcome from those tests to develop, design, fabricate and test a spacecraft version of the sounding rocket instrument,” Cirtain said. Hi-C would again launch from White Sands for this mission.
The most recent Explorer competition that produced a heliophysics mission began in 2010 and ended in April. From among six finalists, NASA selected the Ionospheric Connection, led by Thomas Immel of the University of California, Berkeley, and a smaller Explorer mission of opportunity called Global-scale Observations of the Limb and Disk, a commercially hosted sensor to be developed and managed under Richard Eastes of the University of Central Florida in Orlando.
Launching the next Heliophysics Explorer mission in 2022 would essentially preserve a launch cadence of one mission every four to five years. The recently selected Ionospheric Connection mission is slated to launch in 2017, four years after the Interface Region Imaging Spectrograph. That mission, in turn, launched five years after the Interstellar Boundary Explorer in 2008.
There are several tiers of standalone Explorer missions in NASA’s portfolio — Explorers, Medium-class Explorers and Small Explorers. Cost caps, which exclude the price of a launch, range from $100 million for the smallest to $200 million for the largest. Until recently, each Explorer mission opportunity pitted heliophysics and astrophysics against one another for funding. That changed in 2012.
“Last year the program was split into separately funded and competed Heliophysics and Astrophysics programs,” Jeffrey Newmark, NASA’s Heliophysics Explorer program scientist, wrote in an Aug. 8 email. NASA will adhere to that model moving forward, he added.
Newmark also said the 2016 Heliophysics competition will be for a Small Explorer mission.
As for the next Astrophysics Explorer competition, NASA Astrophysics Director Paul Hertz hopes to announce the start date later this summer, agency spokesman J.D. Harrington said Aug. 8.