Clock Ticking on ISEE-3 Reboot Project

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WASHINGTON — With the spacecraft about to pass out of reach for thousands of years, a volunteer team attempting to bring NASA’s International Sun/Earth Explorer (ISEE)-3 into orbit at Earth-Sun Lagrange Point 1 tried — and failed — to restart the old heliophysics observatory’s two thrusters July 1.

“We were unable to complete the command process today,” the ISEE-3 Reboot Project wrote on its official Twitter account at about 5 p.m. EDT July 1. The Reboot team, spearheaded by NASAWatch.com editor Keith Cowing and space entrepreneur Dennis Wingo, tried sending commands to ISEE-3 during the three hours the spacecraft was in range of its main ground station, the Arecibo radio observatory in Puerto Rico.

The failure is not the end for the ISEE-3 Reboot Project, and a second attempt to ignite the satellite’s two thrusters could take place as soon as July 2, Cowing said in a July 1 phone interview.

A NASA official said the ISEE-3 Reboot Project is clear to keep trying to ignite ISEE-3’s hydrazine thrusters to spin up the old satellite for a planned trajectory correction that, later this month, would send the spacecraft flying by the Moon for a lunar gravity assist that will knock ISEE-3 out of its heliocentric orbit and back toward the stable storage orbit it left in 1982 to chase a pair of comets.

“This is a spin stabilized spacecraft and it’s not spinning quite as fast as we’d liked,” Geoffrey Yoder, NASA’s associate administrator for programs and main point of contact for the ISEE-3 Reboot Project, said in a July 1 phone interview.

On top of that, Yoder said, the relatively primitive ISEE-3, which launched in 1978, cannot report back to ground stations on Earth about the health of its two thrusters or the fuel that remains in its tank until the thrusters are lit.

The ISEE-3 Reboot Project must burn the spacecraft’s two thrusters for a course correction by mid-July to get the satellite into a useful orbit. In order to do that, NASA must first certify that ISEE-3 is able to complete the maneuver, according to a NASA Space Act Agreement signed May 19 with Wingo’s company Skycorp Inc., Los Gatos, California.

The easiest way to do that, Yoder said, was to clear the team to perform the spin-up maneuver. 

For the July 1 spin-up attempt, the ISEE-3 Reboot Project issued spacecraft commands from a temporary mission control facility set up in an office at Ettus Research in Santa Clara, California, about 11 kilometers east of NASA’s Ames Research Center. ISEE-3 mission control at McMoons, an abandoned McDonald’s restaurant on the Ames campus, was without Internet connectivity July 1, Cowing said.

If the spacecraft makes it back to Earth-Sun Lagrange Point 1, Cowing and Wingo plan to resume ISEE-3’s original mission to observe solar winds — charged particles emitted in bursts by the sun — breaking on the outer edge of Earth’s protective magnetosphere. The aim is to give the general public, students in particular, the chance to learn about heliophysics and spacecraft operations first hand. 

That will likely require another crowdfunding campaign, Cowing has said. Just to scrape together the equipment, personnel and operating budget required to reactivate the spacecraft — which NASA shut down in 1997 — the ISEE-3 Reboot Project raised some $160,000 from about 2,200 donors on RocketHub.com. The month-long fundraising campaign wrapped up May 23. 

 

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