"We want to get back to our data analyzing and research-paper writing!" said Lee Stone, president of local 70 of the International Federation of Professional and Technical Engineers, to the crowd, which began chanting: "We want to work! We want to work!"
All but a skeleton crew is now working at NASA Ames Research Center on important missions. As one scientist said: "Ninety-seven percent of us are not going through that gate."
"I'm supposed to be looking for planets, but I'm not," said Kepler mission scientist Natalie Batalha, whose words inspired the crowd to begin chanting: "We love Kepler! We want Kepler!" She added that she would even volunteer her time to continue her work, but she can't.
The crowd also cheered for Brian Day, education and public-outreach lead for LADDEE, the lunar atmosphere and dust environment explorer, when he said LADDEE had "just entered orbit around the moon."
"It's a very interesting story, and unfortunately we aren't telling it," he said.
At Ames Research Center, 1,150 employees are furloughed, Stone said, and about an equal number of contractors and students are affected.
"Normally I'd be trying to prevent foreign countries from trying to hack into our data, but I'm not doing that right now," cyber-security expert Matt Linton said. He said a skeleton crew was still doing that work, but that it would be "insufficient" in the longer term.
Stone, who works on airplane safety at Ames, said that among the projects being delayed was the testing of a new tail section of the Boeing 757 airliner designed to make it "more efficient and safe."
The protest was at times humorous. As one speaker mentioned a type of planet in the solar system, someone in the crowd asked: "Do they have jobs (on those planets)? I'll go!"
A middle school student named Eliana had skipped school for what her dad called the "ultimate civics lesson." She held a sign that stated, "Congress do your job so my dad can do his," while her sister Natalia's read, "Let my daddy work!"
"Science is kind of a continuous act," Linton said. For example, he said, researchers were in the middle of a once-a-year window when planes can fly in and out of Antarctica, to replenish supplies and relieve personnel. A continued shutdown could mean that all research in Antarctica would have to stop for almost a year.
For some missions, "If you don't collect data now, it slips by," Linton said. "Once you halt it, you have to start all over again." He said many people would like to volunteer their time to continue their research, but they aren't allowed.
Linton told the crowd that he wore a shirt with the word "Expendable" on it in irony, to which the crowd began chanting: "We are not expendable! We are not expendable!"
"There's no reason to continue this shutdown," Stone said. "Argue your politics in D.C., but open the government now!"