Dragon 2 DragonFly: Difference between revisions

{{Short description|SpaceX Dragon2 spacecraft prototype}}

{{italic title|string=DragonFly}}

{{Infobox individual space vehicle

| name = ''DragonFly''

| image = Dragon 2 hover test (24159153709).jpg

| image_alt =

| caption = {{Longitem|A ''DragonFly'' hover test in November 2015.}}

| type = [[Space capsule]] prototype

| class = [[SpaceX Dragon 2]]

| eponym = [[Dragonfly|Dragonflies]]

| serial = C201

| owner = [[SpaceX]]

| manufacturer = SpaceX

| first_flight_date = {{Start-date|6 May 2015}}

| first_flight = [[Crew Dragon Pad Abort Test|Pad Abort Test]]

| flights = 1

| time = 109 seconds

| fate = Retired

| location =

| next = [[Crew Dragon C204|C204]]

The '''Dragon 2 ''DragonFly''''' ('''Dragon C201''') was a prototype [[sub-orbital spaceflight|suborbital]] [[Liquid-propellant rocket|rocket-powered]] test vehicle for a propulsively-landed version of the [[SpaceX Dragon 2]]. ''DragonFly'' underwent testing in Texas at the [[SpaceX launch facilities#SpaceX Rocket Development and Test Facility, McGregor, Texas|McGregor Rocket Test Facility]] in October 2015. However, the development eventually ceased as the verification burden imposed by [[NASA]] was too great to justify it.

The ''DragonFly'' test vehicle is powered by eight [[SuperDraco]] [[hypergolic propellant|hypergolic]] rocket engines, arranged in a redundant pattern to support [[Fault tolerance|fault-tolerance]] in the propulsion system design.<ref name=wt20140522/> SuperDracos use a [[Propellant#Rocket propellants|storable propellant]] combination of [[monomethylhydrazine]] (MMH) [[fuel]] and [[Dinitrogen tetroxide|nitrogen tetroxide]] [[Oxidizing agent|oxidizer]] (NTO), the same propellants used in the much smaller [[Draco (rocket engine family)|Draco]] thrusters designed for [[Spacecraft attitude control|attitude control]] and [[Reaction control system|maneuvering]] on the first-generation [[SpaceX Dragon|Dragon spacecraft]].<ref name="faa201311">{{cite web|url=http://www.faa.gov/about/office_org/headquarters_offices/ast/media/20140513_DragonFly_DraftEA_Appendices%28reduced%29.pdf|title=Draft Environmental Assessment for Issuing an Experimental Permit to SpaceX for Operation of the Dragon Fly Vehicle at the McGregor Test Site, Texas, May 2014 – Appendices|last1=James|first1=Michael|last2=Salton|first2=Alexandria|date=November 12, 2013|publisher=Blue Ridge Research and Consulting, LCC|pages=12|last3=Downing|first3=Micah}}</ref>

While SuperDraco engines are capable of {{convert|16400|lbf|N|disp=flip}} of thrust, during use on DragonFly flight test vehicle, each will be [[Rocket engine#Overall performance|throttled]] to less than {{convert|15325|lbf|N|disp=flip}} to maintain vehicle stability.<ref name=faa201311/>

In May 2014, SpaceX publicly announced an extensive test program for a propulsively-landed [[space capsule]] called ''DragonFly''.<ref name=nbc20140521/> The tests were to be run in Texas at the McGregor Rocket Test Facility in 2014–2015.<ref name=nbc20140521>{{cite news|last=Boyle|first=Alan|title=Elon Musk's SpaceX Plans DragonFly Landing Tests|url=http://www.nbcnews.com/science/space/elon-musks-spacex-plans-dragonfly-landing-tests-n111386|access-date=2014-05-22|newspaper=[[NBC News]]|date=2014-05-21}}</ref> A flight test program of up to 60<ref name=faa-eia201408/> flights was proposed.

An outline for thirty of those flights included two ''propulsive assist'' (parachutes plus thrusters) and two ''propulsive landing'' (no parachutes) landing-only test flights, where DragonFly would be dropped from a helicopter at an altitude of approximately {{convert|10000|ft|m|sp=us|disp=flip}}. The other 26 test flights were projected to be [[vertical takeoff, vertical landing]] (VTVL) test flights that will take off from a purpose-built [[launch pad|pad]]: eight were to be ''propulsive assist hops'' (landing with parachutes plus thrusters) and 18 were to be ''full propulsive hops'', where the landing is made with only rocket propulsion, similar to the [[Grasshopper (rocket)|Grasshopper]] and [[Falcon 9 prototypes#Description|F9R Dev]] booster stage test flights that SpaceX also flew out of their McGregor facility.<ref name="faa201311" />

Test flights were planned to include a subset of tests that would test both the DragonFly space capsule and the attached [[Service module|trunk]], an unpressurized structure that typically carries mission-specific cargo and houses the power supply system for Dragon orbital flights. The others were planned to be test landings of only the capsule itself, without the trunk.<ref name="wt20140522">

{{cite news |last=Abbott|first=Joseph |title=Grasshopper to DragonFly: SpaceX seeks approval for new McGregor testing |url=http://www.wacotrib.com/blogs/joe_science/grasshopper-to-dragonfly-spacex-seeks-approval-for-new-mcgregor-testing/article_11d0c40a-e1f6-11e3-a868-001a4bcf887a.html |access-date=2014-05-23|newspaper=Waco Tribune |date=2014-05-22 }}</ref>

A [[Environmental impact assessment|Final Environmental Assessment]] was issued by the [[Federal Aviation Administration|FAA]] in August 2014. The FAA determined that the ''DragonFly'' test program "would not significantly impact the quality of the human environment."<ref name="faa-eia201408">

{{cite web |title=Final Environmental Assessment for Issuing an Experimental Permit to SpaceX for Operation of the DragonFly Vehicle at the McGregor Test Site, McGregor, Texas |url=http://www.faa.gov/about/office_org/headquarters_offices/ast/media/DragonFly_Final_EA_sm.pdf |website=faa.gov |publisher=[[Federal Aviation Administration]] |access-date=2014-08-22 }}</ref> The assessment estimated that the program would take two years for SpaceX to complete and considered a total of 30 annual operations of the ''DragonFly'' test vehicle in each year of operation.<ref name="faa-eia201408" /> SpaceX received a renewal permit from the FAA on July 29, 2016, to continue another year of [[flight test]]ing.<ref>[http://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/Final%20Dragonfly%20Experimental%20Permit%20and%20Orders%20EP%2015-011%207-28-2016%20%28all%20....pdf Final Dragonfly Experimental Permit and Orders EP 15-011A Rev2] {{webarchive|url=https://web.archive.org/web/20160909230158/http://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/Final%20Dragonfly%20Experimental%20Permit%20and%20Orders%20EP%2015-011%207-28-2016%20(all%20....pdf |date=2016-09-09 }} FAA, July 29, 2016</ref>

The DragonFly test vehicle—formerly the Dragon2 test article that was used in the [[Dragon V2#Pad abort test|May 2015 pad abort test]]—was at McGregor for the start of the two-year test program by October 2015.<ref name="nsf20151021">

{{cite news |last1=Bergin|first1=Chris |title=SpaceX DragonFly arrives at McGregor for testing |url=http://www.nasaspaceflight.com/2015/10/spacex-dragonfly-arrives-mcgregor-testing/ |access-date=2015-10-30 |work=NASASpaceFlight.com |date=2015-10-21 }}</ref> However, the development eventually ceased as the verification burden imposed by [[NASA]] was too great to justify it.<ref>{{Citation|last=WordsmithFL|title=Elon Musk, ISS R&D Conference, July 19, 2017|date=2017-07-19|url=https://www.youtube.com/watch?v=BqvBhhTtUm4&t=3890|access-date=2018-08-02}}</ref>

* {{Commons category-inline|Crew Dragon DragonFly}}