Sierra Nevada Corp. is holding preliminary technical discussions with the European Space Agency and the German space agency on a potential collaborative partnership on the company's Dream Chaser space plane, a piloted orbital spaceship being developed for NASA's commercial space taxi program, officials said Wednesday.

Artist's concept of the Dream Chaser space plane docked to the International Space Station. Credit: Sierra Nevada Corp.
 
In separate agreements with ESA and DLR, the German space agency, Sierra Nevada says it is investigating areas for possible cooperation with Europe. Officials said that may include the introduction of European technologies into the Dream Chaser and the use of the spacecraft for European human spaceflight and satellite deployment and recovery missions.

Mark Sirangelo, Sierra Nevada's corporate vice president for space systems, described the agreements as a "framework" facilitating the creation of joint technical teams and the start of low-level dialogue between the company and European industry.

"We are constantly looking at what we can do with the Dream Chaser today, but also with variants of the Dream Chaser in the future," Sirangelo said in a press conference Wednesday. "How can we upgrade it? Are there better avionics, are there other ways to do docking systems? Are there things that exist that might make us better?

"This is really the beginning of that relationship [with Europe] and the beginning of creating mutual teams to be able to make that happen," Sirangelo said.

ESA's agreement with Sierra Nevada was signed in September, according to Elena Grifoni Winters, head of the coordination office for ESA's directorate of human spaceflight and operations. The cooperative understanding between ESA and Sierra Nevada extends through early 2015, Winters said.

Winters said ESA is studying how it could infuse ongoing European developments in docking systems and avionics into the Dream Chaser.

ESA said in a press release that one area of cooperation to be explored is the International Berthing Docking Mechanism being developed in Belgium, Italy and Switzerland.

The docking mechanism has its roots in the X-38 Crew Return Vehicle, a lifting body lifeboat for the International Space Station that was canceled in 2002 before it ever flew in space. QinetiQ Space nv of Belgium is the docking system's prime contractor.

The X-38 would have allowed the space station to support a seven-person crew had it continued with flight testing and been entrusted for lifeboat duty. Russia now handles crew transportation and escape responsibilities with two Soyuz capsules capable of hosting six crew members.

Winters identified cockpit displays and avionics as other areas ripe for partnership between ESA and Sierra Nevada, also building on advancements made in the joint NASA-ESA X-38 program.

File photo of an atmospheric drop test of the X-38 Crew Return Vehicle in July 1999. Credit: NASA/Carla Thomas
 
"The other area in which we were looking at collaboration is on crew displays and crew aids," Winters said. "This is what we call the OAS, the Operational Avionics Subsystem."

The Dream Chaser is designed to take off on top of a United Launch Alliance Atlas 5 rocket, deliver up to seven astronauts to the International Space Station, and return to Earth with a runway landing like the space shuttle at the Kennedy Space Center in Florida.

Sirangelo said Wednesday the Dream Chaser is on track for an unmanned orbital test flight in 2016, followed by a human certification flight in 2017.

With a wingspan of 22.9 feet and length of 29.5 feet, the Dream Chaser is about one-third the size of a space shuttle orbiter.

NASA and Sierra Nevada have a Space Act Agreement to provide up to $227.5 million of NASA funding to the company. NASA makes payments as Sierra Nevada completes Dream Chaser design and development milestones.

NASA's Space Act Agreement runs through August 2014 and includes other milestones, including risk reduction testing, wind tunnel testing, rocket thruster testing, and safety and schedule reviews.

NASA has similar agreements with Boeing Co. and SpaceX worth $460 million and $440 million, respectively. But Sierra Nevada's Dream Chaser is the only spacecraft competing for NASA's commercial crew funding that would return to a runway landing. Boeing's CST-100 and SpaceX's Dragon spacecraft are capsules.

The space agency expects at least one of the companies will be ready to ferry astronauts to the space station by 2017.

Last year, Sierra Nevada announced a deal with Lockheed Martin to construct the Dream Chaser's composite structures at the Michoud Assembly Facility in New Orleans, where the space shuttle's external tanks were manufactured.

Two previous agreements running from 2010 to 2012 provided $125 million in federal funding to go toward the Dream Chaser program.

The space agency also has a $10 million contract with Sierra Nevada to begin the process of ensuring the Dream Chaser meets stringent safety requirements for astronauts.

The Dream Chaser's schedule for a crewed test flight depends on continued NASA funding. The U.S. space agency is currently receiving proposals from Sierra Nevada, Boeing and SpaceX to win another tranche of NASA funding to take the Dream Chaser, CST-100 and Dragon spaceships through flight testing, including a manned mission to low Earth orbit.

NASA officials say they cannot afford to continue financing all three programs, but the agency hopes it can pay at least two companies to proceed with the final phase of development.

The Dream Chaser engineering test article on final approach during its first automated landing test in October. One of the craft's main landing gear failed to deploy, a glitch blamed on hydraulic contamination. Credit: Sierra Nevada Corp.
 
"We've made our own major investment in the program," Sirangelo said. "We expect the program to continue. We have been fortunate to get tremendous support from NASA on all levels ... and we expect that to continue. If for some reason that doesn't, we fully expect the program is going to continue. It's now at a level of maturity where that's possible."

No money has been exchanged between ESA, DLR and Sierra Nevada on the Dream Chaser, but the German space agency is financing a study on a project named Dream Chaser for European Utilization, or DC4EU, to investigate ways the space plane could be used to meet European astronaut and cargo transportation needs to the space station.

Contracted to OHB System AG's Munich-based subsidiary Kayser-Threde, the German-backed study will also look at Dream Chaser's ability to service or retrieve satellites in orbits higher than the space station, according to a Nov. 13 press release from OHB.

Speaking for ESA on Wednesday, Winters said: "We are also open in the future to work together with Sierra Nevada and to explore the possiblity for the Dream Chaser to support our objectives in human spaceflight for the space station and beyond."

Thales Alenia Space, the European aerospace firm which built several pressurized space station modules, is also a partner with Sierra Nevada's Dream Chaser, according to Sirangelo.

"So far, it's ideas," said Johann-Dietrich Woerner, chairman of the executive board of DLR. "We have this framework agreement to put these basic ideas into real projects. This is something to be developed, but there is a clear commitment that we are ready and we are eager to develop it."

With slight modifications to the Dream Chaser's wings, Woerner said the space plane could be launched inside the payload fairing of Europe's Ariane 5 rocket. On the Atlas 5 rocket, the Dream Chaser would launch uncovered without an aerodynamic shroud.

"We could do it without the new development of all the aerodynamics, etc., if we put it within the fairing," Woerner said. "But that would mean that the Dream Chaser would have to be changed a little bit because the wings are little bit too big, so one has to change that ... Or we could put it on top of the Ariane 5 as it is with Atlas and we would have to, of course, recalculate all the aerodynamics."

The Ariane 5 launcher was designed to loft Europe's Hermes mini-space shuttle, a three-person craft that would have flown as high as 500 miles for up to three months. Hermes would have launched without an Ariane 5 payload fairing.

ESA canceled the Hermes program in 1992 before any flight vehicles were built.

Follow Stephen Clark on Twitter: @StephenClark1.