Rendering of an asteroid. NASA will be monitory an asteroid that is set to pass Earth on Halloween.

A new space age is emerging, and the so-called space economy will become a multitrillion-dollar industry within the next two decades, Goldman Sachs is telling its clients.

More than 50 venture capital firms invested in space in 2015, driving more VC dollars into the sector in that year alone than in the prior 15 years combined, analyst Noah Poponak wrote in a Tuesday note to investors. Those firms included SoftBank, Fidelity, Bessemer and the VC arm of Alphabet's Google, among others.

"While relatively small markets today, rapidly falling costs are lowering the barrier to participate in the space economy, making new industries like space tourism, asteroid mining and on-orbit manufacturing viable," Poponak said.

Since 2000, more than $13 billion has been poured into space-related start-ups and established companies, Goldman's research shows. Key players receiving funds are broken down into satellite manufacturers, like Boeing; launch providers, like Lockheed Martin; and operators, such as AT&T or Dish Network.