SNC’s Dream Chaser crew vehicle is preparing for another California adventure, highlighted by a second free flight, approach and landing test in December. Although she was rejected by NASA as a Commercial Crew partner, the Agency is deeply invested in the vehicle’s test program, classing it as “synergistic” with her cargo carrying sister that has earned a NASA future via the CRS2 contract.
Dream Chaser’s Return:
Previously known as the Engineering Test Article (ETA), the Dream Chaser test vehicle enjoyed a successful test program under the support and guidance of NASA’s Commercial Crew Program (CCP).
The milestones – including numerous helicopter trips under tether – all led up to a major test at the Dryden Flight Research Center in 2013.
Up until this point, only historical, computational and wind tunnel data backed Dream Chaser’s ability to enjoy controlled unpowered flight.
“Despite all the computer modeling and simulations, there had not been a lifting body of this type flown since the 1970s,” noted Mark N. Sirangelo, corporate vice president of SNC’s Space Systems business area. “We really wanted to make sure this design would fly.”
That test saw Dream Chaser released high over Edwards Air Force Base, with her automated flight control system gently steering the vehicle to her intended glide slope, with the vehicle adhering to the design flight trajectory without issue.
Less than a minute later, Dream Chaser smoothly flared and prepared to touch down on Runway 22L.
In the final 20 seconds of the flight, the vehicle acquired the runway and lowered her rate of descent to 1.58 feet per second, with an approach speed of approximately 160 knots. This was within predicted parameters.
The timing of landing gear deployment – the main landing gear both port and starboard on the aft of the vehicle, with a nose skid in place of the conventional nose landing gear wheel – was decided by onboard parameters via an onboard ground radar altimeter.
Both the nose skid and the starboard gear deployed as planned. However, the port landing gear door remained closed.
As Dream Chaser touched down, the “weight on wheels” during rollout saw the vehicle begin to lean to the left, with the airframe touching the runway, before skidding off the strip in that direction and kicking up a large amount of dust and sand as she went for a tumble.
With all test objectives met during the flight, the unplanned event of Dream Chaser suffering an accident during rollout actually provided additional parameters on how the vehicle could cope with such a scenario.
The result was a fair amount of cosmetic damage, but no serious impact on the internal structure of the vehicle. Had a crew been onboard, they would have walked away. Even the fluffy dice in the cockpit remained in place.
NASA officials also noted they were impressed with the test and continually showed their support for the vehicle during the company’s recovery from the accident.
However, SNC – somewhat surprisingly – lost out in NASA’s Commercial Crew Transportation Capability (CCtCap) contract award decision – with the Agency opting to press forward with funding for SpaceX’s Dragon 2 and Boeing’s CST-100 (Starliner).
Although SNC has signed a number of agreements with a number of international partners for the potential use of the Dream Chaser for a range of missions, missing out of the Commercial Crew Program (CCP) was a large blow to her future ambitions.
At one point it appeared unlikely that a second free flight – also known as the approach and landing test – would be undertaken, given the final CCiCAP milestone payment would not likely cover the costs involved with completing the test.
However, Dream Chaser received a major boost via another NASA contract, this time based on the delivery of cargo – as opposed to crew – to the International Space Station.
The CRS2 contract, which will involve supply runs to the orbital outpost from 2019, was awarded to SNC’s new version of the Dream Chaser, along with Orbital ATK and SpaceX.
The synergy between the two versions of Dream Chaser has added additional focus on the second free flight of what is now known as the Flight Test Vehicle (FTV – as opposed to ETA).
As promised by NASA ahead of the CCtCAP announcement, the Agency did not abandon the losing partners, providing SNC with a Space Act Agreement (SAA) that will remain active until June 2017.
The result is a more “active” second test, as opposed to a repeat of the landing attempt conducted in 2013, allowing a progression of the data gathering that will feed into the cargo version of the vehicle.
“They want to get some more data and fly Dream Chaser in a more robust flight environment where they can test more of their systems,” noted NASA’s Director of Commercial Spaceflight Development Phil McAlister at the recent NAC meeting.
In fact, Dream Chaser was more than just repaired from her 2013 test, she’s been upgraded as noted by the NASA manager.
“Very impressive, they’ve made a lot of progress on it (and it’s going) to collect a lot of data, with subsonic flight software and GNC – which is a big upgrade compared to the last vehicle, along with full power flight computer performance,” added Mr. McAlister.
“The test is currently scheduled for December, but we added some margin into the SAA which is why it goes out to June 2017.”
With Dream Chaser now finding a role for NASA in the CRS2 contract, the test of the FTV – although not the vehicle that will launch cargo to the ISS – has a large amount of synergy with the ambitions of the CRS2 role for Dream Chaser.
“It’s the crewed Dream Chaser, but obviously what we can learn we can apply to CRS2, so that’s another synergistic opportunity I would say. These are all learning opportunities for us. So this can help us on the CRS contract.”
SNC also cited the marriage between the completion of its Commercial Crew obligations and the path to the CRS2 Dream Chaser.
Noting the upgrades – involving additional critical tests to validate the Dream Chaser’s orbital flight software and calculate the spacecraft’s handling and performance characteristics – the test data will be used to confirm Dream Chaser’s subsonic aerodynamic properties as well as flight software and control system performance requirements.
“These tests are significant for us in multiple ways; building on our previous flight test, completing a significant milestone under our CCP agreement, as well as gathering crucial data that will help complete the design of the vehicle being built for our CRS-2 contract,” added Mr. Sirangelo.
Known as “Phase Two flight test efforts”, Dream Chaser’s return to California will be “highly supportive of, and executed in parallel with continued work being done by SNC under the NASA CRS-2 program.”
The test will “act as a bridge between previous work with CCP and the next-generation vehicle currently under development for the forthcoming International Space Station cargo resupply missions.”
The company is aiming to build two cargo Dream Chasers, able to fly a total of 30 times over a 10 year lifetime.
(Images: Via SNC and L2 – including renders from L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to MCT, SLS, Commercial Crew and more) L2 images can be *found here*)
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