 -- Who says boys and girls can’t both like rocket ships and dinosaurs?

Shoreline, Washington, moms Jennifer Muhm and Malorie Catchpole are the co-founders of buddingSTEM, a science-themed clothing line for girls between 18 months old and 8 years old. “STEM” stands for science, technology, engineering and math.

The clothing line features dresses, leggings, t-shirts and underwear with patterns like rocket ships, trains, and dinosaurs in both blue and pink or teal and gray.

“We’re not anti-princess. We’re not anti-pink. We’re not anti-girly. We just think there needs to be more than just that offered for our girls,” Muhm, 37, told ABC News.

The moms, who don’t have backgrounds in the fashion business, say the idea for buddingSTEM was born out of their own personal experiences with their girls.

Muhm, who works in public affairs, said her daughter, now 5, really wanted to be an astronaut for Halloween in 2013. But when the costume catalogs came in the mail, her daughter noticed that only boys were shown wearing the astronaut costume.

“She looked at me and said, ‘I can’t be an astronaut. They’re only for boys,’” Muhm said.

“We talked about it because we were both frustrated about it,” Catchpole, 34, an attorney, told ABC News.

Catchpole said her own daughter, now 3, is “very into trains.” But when she and her husband wanted to buy her underpants with trains on them as a gift one Christmas, they could only find boy’s underwear. Catchpole said she bought them anyway.

“I was actually at their house on Christmas and saw the boys’ underpants under the tree, and it was that moment that it kind of clicked,” Muhm said. “I said, ‘You know what, Malorie? We should make underpants with trains on them … and then we thought why just underpants: there are no dinosaurs or rocket ships on leggings or dresses for girls.”

When they were unable to find anything like it already on the market, the moms did their research and reached out to people in their networks.

Eventually they met with a textile designer, who turned their sketches into prints for fabric, and a manufacturer.

By April 2014, Muhm and Catchpole filed their business registration for buddingSTEM. They recently surpassed their initial goal on Kickstarter, raising over $45,000 to get buddingSTEM started. The buddingSTEM clothing line will be available for sale on their website in July.

“One of the things that I’m happiest about … is what I think we’ve shown our daughters,” Catchpole said. “We’re two working moms. We don’t have a background in fashion, and we saw a need and we worked hard.”

“If there is something that is not fair -- because my daughter will say that it is not fair -- you can actually start working toward doing something about it,” said Muhm.