Once ready, Dream Chaser will carry up to seven people to the orbiting complex. It will launch vertically upon an Atlas 5 rocket and then, like the shuttle, land on a runway horizontally.
Sierra Nevada aims to have Dream Chaser ready for flight as early as 2016, and has passed several key milestones along the road to that launch date.

NASA has provided millions of dollars to the company under the Commercial Crew Program that is intended to provide financial incentives and NASA facilities to firms that are interested in running astronauts up to the station.

Based on secret Soviet design Sierra Nevada, founded in 1963, describes itself as having expertise in electronics, avionics, and communications systems. The Colorado-based firm has a space systems division that works on areas such as propulsion, small satellites and components for customers.

The spacecraft has a bit of a tangled history. Its design is mainly based on the HL-20 - a NASA spacecraft design from the 1980s that was itself based on a Soviet spacecraft called the BOR-4. But the HL-20 design was never used for space.

SpaceDev resurrected the design. According to Ars Technica, in 2006 the firm signed a licensing agreement with NASA to reuse HL-20 for the Dream Chaser concept.

"We have tried to make it clear that SpaceDev does have plans of our own in terms of human spaceflight, both orbital and suborbital," said Jim Benson, the firm's founding chairman and CEO, in a SPACE.com 2004 , interview.

Despite the agency heritage, SpaceDev failed to get funding under the initial NASA Commercial Orbital Transportation Systems (COTS) program to fund commercial spacecraft. Benson left SpaceDev. in 2006 to found a new space tourism company, but died in 2008 of a brain tumor.

SpaceDev, meanwhile, merged with Starsys Research Corp. and continued work with NASA under a non-reimbursable Space Act agreement in 2007.

That same year, it signed a memorandum of understanding with United Launch Alliance to put Dream Chaser on an Atlas 5 rocket. This entailed some design changes, but the companies were optimistic from the early days that this arrangement would work.

Sierra Nevada purchased SpaceDev. in 2008, which added a new space systems business area to Sierra Nevada's divisions.

“The acquisition of SpaceDev ... represents a dynamic expansion of [Sierra Nevada]’s space technology capabilities," stated Fatih Ozmen, Sierra Nevada's chief executive, after the acquisition was finalised in December 2008.

“We believe that combining SpaceDev’s unique technological offerings, manufacturing capabilities and talented team with our existing space business and technology base will allow us to significantly increase our capacity and scalability while better serving our customers and making us a leader in space technology with access to a much wider customer and technology base.”

NASA money for development
In more recent years, the company has met with financial success in winning NASA contracts. According to its website, it received $100 million in Commercial Crew Development (CCDev) awards and has passed all tests on time and on budget.

Most recently, in August 2012 it was one of three companies that received money under the Commercial Crew Integrated Capability (CCiCap) award, which represents the next step in getting crew capsules ready for space.

CCiCap is the third phase of commercial crew development, and is supposed to help companies in the latter stages of spacecraft work to get their ships ready for flight.

Sierra Nevada's contract, which is worth up to $212.5 million, will pay out money as the company progresses through certain milestones. It must meet nine of them to qualify for the money.

"We're very pleased today to receive the award from NASA as a recognition of our work. We think the whole program is a very successful public-private partnership," Mark Sirangelo, corporate vice president of Sierra Nevada's space systems division, said Aug. 3, 2012 following the CCiCap announcement. The company also passed several major tests in 2012, most notably a "captive carry" flight test where it rode below a helicopter. Next, sometime in the first six months of 2013 , Sierra Nevada plans to put an uncrewed Dream Chaser to the test. The spacecraft will descend and land at NASA's Dryden Flight Research Center in California.

"These flight tests are similar to the approach and landing tests that NASA conducted on the space shuttle prior to the first launch of the shuttle," said John Roth, Sierra Nevada Space Systems vice president of business development, in a SPACE.com story that ran in January 2013.

"The [Dream Chaser] program is also continuing significant hardware testing throughout 2013 to continue to advance the design of our subsystems." [Infographic: Sierra Nevada's Dream Chaser Space Plane]

Aiming for 2016
Dream Chaser, its makers said in 2012, should be ready for spaceflight by 2016. This puts it on schedule for NASA's ambitions to send private American spacecraft aloft around 2017.

The company is not alone in vying for commercial work. Space Exploration Technologies (SpaceX's) Dragon spacecraft, Boeing's CST-100 spacecraft, and Blue Origin's program are other companies looking to put their hardware in orbit.

As its differentiator, Dream Chaser advertises features such as a "large cross range with frequent landing opportunities" and its reusability, saying that the spacecraft is "designed for simple maintenance and a quick turnaround."

In 2012, as the Louisville, Colo.-based Sierra Nevada announced expansion to Florida, officials said American pride was one of the reasons they are working on the program. The United States has been dependent on Russian Soyuz spacecraft to bring astronauts to the International Space Station since the shuttle flight program retired in 2011.

"The goal that we have here is really quite simple - we want to take the 'Help Wanted' signs out of the windows in Russia and bring it back here," Sirangelo said in May that year.