SNC Captive Carry test sees Dream Chaser take flight

by Chris Bergin

Sierra Nevada Corporation (SNC) took their spacecraft for a ride on Tuesday, allowing it to taste the Colorado air via a Captive Carry test near the Rocky Mountain Metropolitan airport. Lofted by a Sikorsky Skycrane helicopter, the Dream Chaser was being tested ahead of its debut Free Flight Test later this year.

Dream Chaser:

SNC’s Dream Chaser Space System (DCSS) is one of the major players in the Commercial Crew arena, earning the company an $80m award under the NASA CCDev-2 effort.

The Dream Chaser is the only reusable lifting body vehicle in the running to transport American astronauts to Low Earth Orbit (LEO) destinations, such as the International Space Station (ISS).

The vehicle is a crowd-favorite, not least due to its appearance as a baby shuttle orbiter, an iconic “space plane” shape that was embedded into the mindset of the space program’s followers during the 30 year reign of the world famous NASA orbiters.

The spacecraft has a NASA heritage itself, ranging back to the NASA Langley HL-20 spaceplane concept from the 1980s. Also, like the space shuttle, Dream Chaser will return to Earth by landing on a runway.

SNC selected the Atlas V launch vehicle for Dream Chaser’s ride uphill, a popular rocket for a number of company’s with Commercial Crew aspirations. The United Launch Alliance (ULA) have a long standing relationship with Dream Chaser, ranging back to a Memorandum Of Understanding (MOU) in 2007.

For the marriage of the two vehicles to become a reality, the ULA teams are working with a high-fidelity Emergency Detection System (EDS) testbed in the Atlas V LV systems integration laboratory (SIL) to demonstrate the system required for Human Rating requirements. This work is being conducted under a Space Act Agreement (SAA).

As noted in a previous NASASpaceFlight,com article, SNC have been making good progress on the Dream Chaser, working through 19 milestones per the CCDev-2 contract, as they push towards the final objective of a Free Flight Test.

The latest test took place on Tuesday, after the Dream Chaser – a full scale version, without propulsion elements – was spotted in a field surrounded by support trucks and workers near the Rocky Mountain Metropolitan airport in Colorado.

Following the installation of harnesses, a Skycrane helicopter arrived to lift Dream Chaser into the air, catching the attention of hundreds of people driving down surrounding roads.

With photographs and video (L2 – LINK) showing the Dream Chaser into the air, the Skycrane took the spacecraft through a series of banks, with a small parachute out of the back of the Dream Chaser helping to keep the vehicle stable and level during the test.

According to the CCDev2 Optional Performance Milestones and Success Criteria document, this test appears to be Milestone 12 on the list of objectives.

“Optional Milestone 12: ETA Captive Carry Flight Test Description: Conduct ETA captive carry flight test on carrier aircraft to characterize integrated vehicle performance,” noted the document.

“Success Criteria: Completion of ETA captive carry flight as outlined per the flight test plan.”

Pointing to the importance of this test, the document also adds that Milestone 18 was in itself a readiness review of the Captive Carry test, a milestone clearly passed to allow for Tuesday’s event to take place.

“Milestone 18: ETA Captive Carry Flight Test Readiness Review Description: Complete Captive Carry Flight Test Readiness Review to verify ETA readiness for captive carry testing. SNC shall provide briefing of the Flight Test Plan and ETA vehicle captive carry test readiness and a hard copy of the presentation materials and responses to NASA questions concerning captive carry test readiness.

“Success Criteria: Meet criteria specified in the SNC Captive Carry Flight Test Readiness Review Entrance and Success Criteria.”

The results of Tuesday’s test will also feed into the major – and final – CCDev-2 objective of a high-altitude free flight – or “drop-test” – involving the vehicle riding with a carrier airplane – depicted as White Knight 2 in documentation – before being released for a landing attempt at Edwards Air Force Base in California.

While Dream Chaser will approach and land like a plane, the vehicle will employ a skid on the nose, as opposed to wheels.

Such a skid system – attached and deployed via a hinge in the nose – has the advantages of being lighter, simpler, less to fail, and removes the need for a steering system.

“Optional Milestone 19: ETA Free Flight Test. Description: Conduct piloted ETA Free Flight test from carrier aircraft to characterize handling qualities and approach and landing,” added the document.

“Success Criteria: Completion of ETA Free Flight as outlined per the flight test plan.”

In between Tuesday’s test and the Free Flight, SNC will continue to build CFD (Computational Fluid Dynamics) models, in tandem with their own wind tunnel data, as the design continues to be qualified via advanced development techniques. Most of these objectives are covered in Milestone 13 and will also involve – as recently reported – the use of Atlas V/Dream Chaser scale models.

Testing of Dream Chaser’s non-toxic hybrid motors (HTPB, N2O) – which have been built in-house – and Reaction Control Systems (RCS) utilizing N2O and Ethanol is also listed on the latter milestones for the CCDev-2 effort.

(Images via SNC, ULA and L2 – via the new DC section, *L2 members click here* Tuesday’s Test Photos and videos provided by NSF’s Lee Jay Fingersh)

(With the shuttle fleet retired, NSF and L2 are providing full transition level coverage, available no where else on the internet, from Orion and SLS to ISS and COTS/CRS/CCDEV, to European and Russian vehicles. 

(Click here: http://www.nasaspaceflight.com/l2/ – to view how you can access the best space flight content on the entire internet)

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