Blue Origin, the space company founded by Jeff Bezos, expects to fly its space tourism rocket at least two more times before it puts the first people on board.

The company is developing the New Shepard rocket system for its space tourism business. Blue Origin is still hoping to fly people on New Shepard this year, although the company noted in a meeting with reporters on Tuesday that 2019 is quickly coming to an end, so those plans may move to 2020.

Blue Origin also filed an application for its next test flight with the Federal Communications Commission (FCC) on Tuesday. The filing is "for Flight #12 of the New Shepard space launch booster and capsule" and has an operational window beginning in November. To be clear, that's not necessarily when Blue Origin will next launch New Shepard, but rather the earliest time they could with federal approvals.

New Shepard would launch six passengers on a ride past the edge of space, where they would float in zero gravity for 10 minutes before returning to Earth. The rocket's capsule features massive windows, which will give expansive views of the Earth once in space.

CEO Bob Smith has talked about the first crewed flight of New Shepard happening as early as the end of 2018 – but that goal has steadily been pushed back. Smith, in an interview with CNBC on Tuesday, explained why Blue Origin has delayed the first crewed flight and continued to test.

"It's really the robustness of our entire system. It's not one individual thing that's driving [these delays]," Smith said. "It's us being cautious and thorough with the total systems we need to verify."

He noted that Blue Origin has been pushing the limits of its software and hardware, as well as testing its BE-3 rocket engine for extreme and unexpected situations.

"When we came back for our seventh mission [in December 2017], we actually came back with a new booster as well as a new capsule configuration," Smith said.

"Between the seventh flight and subsequent flights, we've not only introduced another pair of boosters and capsules but we've also introduced a series of improvements to that overall configuration that allow us to have higher confidence that the design is robust," Smith added.