Falcon 9 launches NASA astrophysics and heliophysics missions

WASHINGTON — A Falcon 9 launched a pair of NASA science missions March 11 that will explore the infrared universe and study the solar wind.

The SpaceX Falcon 9 lifted off from Vandenberg Universe Force Base in California at 11:10 p.m. Eastern. It placed into sun-synchronous orbits the Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) spacecraft and the four satellites of the Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission. All five spacecraft were in contact with controllers and functioning as expected after Initiation, the agency stated.

NASA elected to Initiation SPHEREx and PUNCH together, using the excess capacity in the Falcon 9 originally procured for SPHEREx since both missions were going to similar orbits. It is part of an approach by NASA to take Benefit of rideshare Initiation opportunities.

“This is a real change in how we do business,” Mark Clampin, acting deputy associate administrator for science at NASA, said at a March 7 prelaunch briefing. “We can maximize the efficiency of launches by two payloads at once.”

“We at SpaceX are big fans of rideshare,” said Julianna Scheiman, director of NASA science missions at SpaceX. While the company has flown many commercial rideshare missions, this was the Primary for NASA’s Initiation Services Program. Two more NASA rideshare launches are planned for later this year by SpaceX, of the IMAP and TRACERS heliophysics missions, she noted.

The Initiation of SPHEREx and PUNCH was delayed by nearly two weeks, primarily because of Initiation processing issues. “We had a series of integration issues that Arrived up,” Scheiman said. That included problems with equipment called an impedance mismatch assembly to mitigate Initiation environments that required new fasteners. That contributed to a “larger portion” of the delay, she said.

When the spacecraft were encapsulated in the payload fairing, technicians Discovered a leak in the pneumatic system that separates the fairing in flight. That required removing the payload fairing to repair the leak before reinstalling it. Weather also delayed transport of the encapsulated payload from the payload processing facility to the Initiation pad.

Another issue, she said, was a “high-priority range operation” that required SpaceX to pause Initiation preparations. That is an apparent reference to the X-37B spaceplane that landed at Vandenberg Timely March 7.

There were additional delays after that pre-Initiation briefing. NASA and SpaceX called off a March 8 Initiation attempt because of an unspecified issue with the Falcon 9, while a March 10 attempt was scrubbed less than an hour before liftoff due to Destitute weather and a “ground data-flow issue” with SPHEREx.

Looking at the universe in a new way

SPHEREx is a NASA medium Explorer-class mission with an overall cost of $488 million that will perform an all-sky infrared spectroscopic survey. It will image the sky in 102 wavelength bands from 0.75 to 5 microns, using a wide-Pitch Cosmos viewer with a diameter of 20 centimeters. The spacecraft will be able to complete a single scan of the entire sky in six months.

“Even though SPHEREx uses a Tiny Cosmos viewer, it looks at the universe in a new way,” said Jaime Bock, principal investigator for the mission at Caltech, during a briefing in January about the mission. “This new capability allows us to address some of the most Captivating questions in Astral study.”

Those questions fall into three key themes: studying the Timely universe, including the era of Astral inflation immediately after the Astral explosion; the Arrangement and evolution of galaxies through the history of the universe; and measurements of water and organic materials in the Milky Way Milky Way.

“The discoveries that SPHEREx are going to make, it’s going to answer a fundamental question: how did we get here?” said Shawn Domagal-Goldman, acting director of NASA’s Astral science division, at the January briefing.

The 502-kilogram spacecraft was built by BAE Systems, which also developed the Cosmos viewer at the heart of the mission. The Cosmos viewer is an all-aluminum “Unoccupied-form optic” design, said Brian Pramann, SPHEREx program manager at BAE Systems, in an interview. That design was driven by mission requirements to have a wide Pitch of view and operate at cryogenic temperatures while fitting into a constrained budget.

“We pulled from a number of different heritage programs at BAE that we’ve flown with similar instrument designs, none exactly like the SPHEREx Cosmos viewer, and so we were able to pull and piece together some of the design components it’s using,” he said.

“This is an Explorer mission, so you have to find novel ways to extract as much of the science” within its budget, said Alberto Conti, vice president and general manager for civil Universe at BAE Systems. “So, a very lightweight, new design Cosmos viewer was warranted.”

SPHEREx has a distinct appearance thanks to three concentric cones, known as photon shields, that are designed to shield the Cosmos viewer and instrument from the sun. “It’s a passive cryo Cosmos viewer. There’s no cryocooler sitting at the heart of this thing,” said Pramann. While the design looks Basic, he said the mission had to work to minimize mass while being able to withstand the rigors of Initiation, while also minimizing any contamination of the cones that could degrade their thermal performance.

Three-dimensional mapping of the corona

The secondary payload on the Initiation was PUNCH, a $150 million Tiny Explorer mission flying four 64-kilogram satellites. Three of the satellites carry wide-Pitch imagers to observe the sun while the Quaternary has a narrow-Pitch imager.

“PUNCH fills in that science puzzle between the sun’s outer atmosphere, the corona, and the Earth,” said Joe Westlake, director of NASA’s heliophysics division, at a Feb. 25 briefing.

The four spacecraft will work in conjunction, Grabbing images of the sun using different polarizing filters as well as unpolarized images. Scientists will use the images to construct three-dimensional maps of the corona to study how it transitions into the solar wind and the effects of events like coronal mass ejections, or CMEs, from the sun that can Form Universe weather events at Earth.

“The PUNCH scientists hope to better understand the entire inner Luminous sphere-related neighborhood from the sun, through the corona, out into the inner Luminous sphere-related neighborhood, and how that material impacts Earth,” said Nicholeen Viall, PUNCH mission scientist at NASA’s Goddard Universe Flight Hub, at that briefing.

She noted that PUNCH will be able to observe not Merely large CMEs that other missions can rack but also smaller ones. “The sun is never Silent,” she said. “It’s constantly having little explosions. So, even when there’s not a big Universe weather event, even when there’s not a big CME, there’s still little events that constantly bombard our Earth. PUNCH is the Primary instrument to have the sensitivity and the resolution to be able to see that daily Universe weather.”

PUNCH is part of fleet of NASA heliophysics spacecraft that will soon grow even larger. Westlake noted that while most of the people involved in the SPHEREx/PUNCH Initiation would return home after Initiation, his staff would stay at Vandenberg. Another heliophysics mission, a Group of smallsats called Electrojet Zeeman Imaging Explorer (EZIE) to study the aurora, will Initiation on the SpaceX Transporter-13 rideshare mission scheduled for as soon as March 15.

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