SpaceX DragonFly arrives at McGregor for testing
SpaceX’s DragonFly test vehicle has arrived at its test facility in McGregor, Texas. Following a method used by NASA to test the Morpheus lander, which was utilized to test green propellant propulsion systems, autonomous landing and hazard detection technology. DragonFly will be attached to the large crane, and a series of test firings of its SuperDraco thrusters twill occur to simulate landings.
The Grasshopper program, based at the McGregor test center, was to test the re-usable rocket system, and now DragonFly will attempt to follow in its footsteps, as the spacecraft sets up for a series of tests aimed at the ultimate goal of landing under its own propulsive power.
On the back of the transportation, the Dragon and Grasshopper appeared briefly together – it could be a match made in heaven!
Initially, DragonFly won’t be reaching the heights of the Grasshopper or the since-deceased F-9R Dev-1 test rocket. This is partly because of the approach of incremental testing from Space X, and also due to the FAA permit.
Although the permit also calls for numerous additional constraints, such as a 3,000-foot safety clear zone, the test will be monitored close up by numerous engineering cameras, and likely – per SpaceX’s tradition – to result in a specular video of the testing to be released to the public.
Some have described the spectacle along the terms of the craft ‘dancing’ on the cable, as previously seen by NASA’s Morpheus project. The Morpheus was successfully tested in this way, and later flew with being tethered to the crane, before failing.
The DragonFly will follow a similar path to Morpheus. Sporting four steel landing legs and weighing in at 14000 lbs unfueled, the initial tests will shake out the SuperDraco thrusters and prepare the vehicle for an ambitious test regime.
DragonFly testing will be housed at a 40-foot square pad near the SuperDraco facility.
Pending permit requirements, four kinds of test flights are envisioned after the crane-based testing has been completed.
These include the “Propulsive assist landing” test – which will see DragonFly dropped from helicopter aided by three parachutes. This will be followed by the “Fully propulsive landing” test – again utilizing a helicopter and parachutes, concluding with a five-second firing of the SuperDracos for a smooth landing.
Next would be the “Propulsive assist hop” test. This would call for the DragonFly to be self-launched via a 12.5 second firing of the SuperDracos, removing the helicopter from testing. It would include parachute deployment assist, but with only two chutes, prior to a propulsive landing.
Finally, the test series calls for a “Fully propulsive hop” test, not unlike the Grasshopper tests. During this test, the DragonFly will rise to approximately 7,000 ft AGL, firing its engines for approximately 12.5 seconds to achieve this height.
The engines would then throttle down in order to descend, with the engines firing for an additional approximate 12. 5 seconds, allowing the DragonFly to make a powered landing on the launch pad.
The SuperDracos – burning a combination of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) – that will be at the heart of the testing have already enjoyed a successful test as a group, firing together during the successful Pad Abort test at SpaceX’s SLC-40 Pad at Cape Canaveral. That Pad Abort vehicle has now been revamped into the DragonFly.
The liquid SuperDraco engines, built into the side walls of the Dragon spacecraft, have a major role during an abort, producing up to 120,000 pounds of axial thrust to drive the Dragon and crew safely away from a failing launch vehicle.
They can reach full thrust within approximately 100 milliseconds of the ignition command.
The utilization of the same engines for a propulsive landing capability ensures they will always find a role during Dragon 2’s future role.
Dragon 2 – which is set to launch to the ISS under NASA’s Commercial Crew contract – will initially land under parachutes, prior to progressing towards propulsive landing attempts. Parachutes will remain installed on the spacecraft, in order to provide redundancy.
The initial DragonFly testing is expected to take place in a matter of weeks, following on from the full-duration static fire test for the first upgraded “Full Thrust” Falcon 9 first stage.
The stage, which is set to provide the initial push uphill for the ORBCOMM-2 mission – is back on the test stand at McGregor and is currently undergoing engine re-installation in preparation for its final test ahead of shipping to Cape Canaveral for SpaceX’s Return To Flight mission that is likely to take place in early December – although officially the target remains in late November. Watch this space!