Sierra Nevada Corporation’s Dream Chaser ETA (Engineering Test Article) is just days away from its first free flight milestone. The NASA Commercial Crew Program (CCP) candidate is now in final preparations for its drop test that will result in her conducting an automated approach and landing at the Dryden Flight Research Center in California.
Dream Chaser’s Big Day:
Following a slight delay, caused by the recently-ended Government shutdown, SNC are now just “days away” from carrying out the greatly-anticipated drop test, allowing the ETA to fly on her own for the first time.
Dream Chaser has flown twice, on the end of a cable hooked up to an Erickson Air-Crane helicopter, during two captive carry tests – the first at her home base in Colorado, followed by a second at Dryden.
N164AC “The Incredible Hulk” was used in Colorado, while N179AC “Elvis” had the honor of lofting the ETA in California.
This latest test will be a huge leap forward for the “baby orbiter”, with a test that is aimed at proving her ability to glide towards a runway for a safe landing, one of the key differences Dream Chaser boasts, when compared to its two major Commercial Crew competitors.
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). All the other commercial crew competitors are of the capsule design.
SNC shipped the ETA to Dryden on the back of a truck, allowing Dream Chaser to join an illustrious list of vehicles that spent their early years testing their capabilities at the famous Californian facility.
The best-known historical association is with NASA’s lifting bodies and more famously Enterprise, following her series of Approach and Landing Tests (ALTs) in the 1970s, paving the way for her orbital sisters to learn how to land during the 30 year career of the Shuttle.
Since arriving for her Californian working holiday, SNC have performed runway tow tests tests at various speeds, pulling the ETA via a pickup truck on the concrete runways.
Range and taxi tow tests are standard for winged vehicles that touch down on a runway to prove the overall spacecraft handling post-landing.
The key test element for the ETA will involve the drop test, conducted via the use of a helicopter, carried out early in the morning, in near darkness, before the Californian weather becomes too warm to fly the helicopter at the altitudes required for the testing.
No one will be riding in the ETA, with the vehicle completely automated via its onboard control. The only command that will be sent to the vehicle will be the release from the helicopter, along with the potential to abort and deploy a parachute, should she go off course.
There are three attach points on the ETA, a requirement related to what was initially planned to be drop tests from the White Knight 2 aircraft – a carrier option that was later cancelled. The actual release will be electrically actuated from the helicopter.
In preparation for the event, Dream Chaser’s flight computer, along with its guidance, navigation and control systems were tested during the second captive carry test. The landing gear and nose skid also were deployed, allowing the ETA to prove she was ready for the upcoming milestone.
Known as the approach-and-landing free-flight test, the ETA will enjoy a period of free-flight after release, with a glide towards the lake bed, prior to a level glide, and landing.
There will be at least two drops tests for the ETA, although the schedule – including the actual date of the initial drop test – are still a closely guarded secret. Weather and wind constraints will play a factor in when SNC conduct the first drop test, which is understood to be just days – as opposed to weeks – away.
Unlike the Enterprise ALTs, which were covered in depth by NASA, SNC do not appear to be courting media interest for the drop tests, although it is expected SNC and NASA will release video of the test at a later date.
SNC are working through the milestones associated with the their Commercial Crew Integrated Capability (CCiCap) initiative award, part of NASA’s Commercial Crew Program – which has been providing funding alongside private sector investment – in a drive to allow NASA astronauts ride uphill on US vehicles to the ISS.
Continued lack of full funding has since resulted in the first flight of NASA astronauts on a commercial vehicle – known as USCV-1 (US Crew Vehicle -1) – being delayed to the end of 2017, with the threat of a further slip should funding continue to be less than required.
The irony behind these political decisions to “save” money, by pressuring the Commercial Crew Program, has resulted in NASA having to renegotiate extensions to their arrangement with the Russians for crew transportation, at a cost of several hundred million dollars.
While Boeing’s CST-100 spacecraft is one of Dream Chaser’s competitors,SpaceX’s Dragon currently leads the way, having flown to the ISS three times.
With a potential CCP down-select coming next year, SNC will be hoping to have a number of successful drop tests under their belt, ahead of unveiling what is understood to be a highly impressive Dream Chaser Flight Test Vehicle (FTV), which is currently under construction.
Should SNC continue to be awarded support via the Commercial Crew Program (CCP), Dream Chaser will prepare for a test mission on its launch vehicle of choice, the United Launch Alliance (ULA) Atlas V in the second half of this decade.
(Images via L2 – via the impressive DC section, *L2 members click here* – with additional images via SNC and NASA)
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