SpaceX DragonFly: propulsive landing testbed

[DocM]

DragonFly RLV = DragonRider propulsive landing testbed

AKA a brown-pants landing ;)

* 2014-2015

* up to four steel landing legs

* 6,350.3 kg (14,000 lbs) unfueled

* 1,514 liter (400 gallon) propellant load

4 types of test flight;

* propulsive assist hop (self launched, parachute deploys, like a pad abort)

* fully propulsive hop (like Grasshopper)

* propulsive assist landing (parachutes & rockets, like Soyuz but with a higher altitude terminal burn)

* fully propulsive landing (dropped from helicopter)

FAA Draft Environmental Assessment and other experimental permits:

http://www.faa.gov/about/office_org/headquarters_offices/ast/environmental/review/permits/

Fully propulsive landing (old video)

[DocM]

SpaceX is currently considering two locations for the DragonFly RLV launch operations within the McGregor test site: the existing Grasshopper launch pad and the DragonRider test area. If operations would occur at the DragonRider test area, construction of a 40 ft by 40 ft launch pad would be necessary....

The DragonFly RLV is the Dragon capsule with an integrated trunk (which may or may not be attached during a DragonFly operation) and up to four steel landing legs. The Dragon capsule primary structure consists of a welded aluminum pressure vessel, primary heat shield support structure, back shell thermal protection system support structure, and a nosecone. This structure supports secondary structures including eight SuperDraco engines (two in each of the four modules [quadrants]), propellant tanks, pressurant tanks, parachute system, and necessary avionics. The propulsion system includes four self?contained quadrants with independent sets of propellant tanks for system redundancy. The SuperDraco engine uses a fuel?centered injector to provide appropriate performance for the application. It is also designed to seal off both fuel and oxidizer from the combustion chamber, enabling operation with fast shut?off and limited propellant ?dribble? volumes.

The DragonFly RLV weighs approximately 14,000 pounds (lbs) un?fueled, with a height of 17 ft and a base width of 13 ft. Each pair of SuperDraco engines (eight total engines) are mounted to a monolithic aluminum bracket. This bracket is connected to the pressure vessel with three mounts.

[FloatingFatMan]

I just want to know when we're going to see the first full re-entry and controlled landing.

[DocM]

Depends on the FAA and KSC issuing the permits. The ORBCOMM launch will do another sea landing, the Dragon 2 MaxQ test will attempt a land landing at Vandenberg, so a full launch return to KSC should happen later in the year.

More on DragonFly...

Propulsive Assist

For the propulsive assist test, a helicopter (an Erickson E?model or equivalent) would arrive at the McGregor test site from Waco Regional Airport. The DragonFly RLV would then be tethered to the helicopter using a cable. A maximum of 300 gallons of propellant would be loaded into the DragonFly RLV for this test. The helicopter would take off with the DragonFly RLV attached and reach an altitude up to 10,000 ft. Once at that altitude, the DragonFly RLV would be released from the tether and three main parachutes would be deployed. The engines would not fire until the vehicle descends to approximately 98 ft above ground level (AGL). The engines would fire for approximately 5 seconds, and the RLV would make a powered landing. This type of operation would last approximately 30 minutes from helicopter take?off to DragonFly RLV landing.

The test would be designed so that almost all fuel on board is used prior to landing. All fuel valves would shut automatically and retain any residual fuel in the capsule.

Conference video showing propulsive assist landing

[PaulRocket]

Any word on wether they will present SpaceX spacesuits on the 29th?

Elon tweeted last year he was hoping to unveil them by the end of this year but didn't, so it would be a good opportunity to do so along the Dragon 2.

[Beittil]

Orbital Outfitters apparently completed the mock-ups of the SpaceX suits a long time ago already, so it's not like they do not have anything to show :p

 

 

 

Orbital Outfitters

14 mei 2012

We also completed suit mock-ups for SpaceX for their NASA crew trials. Sorry, suit photos are still classified. But here is a nice group shot of the whole team.

 

Heh, 2 years ago it seems. wow :D

[DocM]

Hard telling what will be announced on May 29. Still waiting for a time, plus there will be a YouTube interview/webcast by Gwynne Shotwell in early June.

The large DragonFly EIS pdf has tons of info, and is being crawled all over.

One thing we learned was the duration of the SuperDraco test burns; 5, 12.5 and burns totalling ~25-30 seconds. People are interpreting these to be abort, terminal landing burn dropped from a chopper, and terminal landing burn after a self-propulsion to the test altitude.

[PaulRocket]

Real Dragon v2 looks awesome!!!

[DocM]

This one is intended for an orbital mission, probably the first unmanned test flight next year.

[+Warwagon MVC]

I think instead of all that fuel they need a HUGE magnate on the bottom of the ship that they drop on the metal plate instantly stops them and hovers them over the ground!

[FloatingFatMan]

I think instead of all that fuel they need a HUGE magnate on the bottom of the ship that they drop on the metal plate instantly stops them and hovers them over the ground!

 

That would make astronaut soup...

[PaulRocket]

When can we expect the first Dragon v2 tests? In June or later?

[DocM]

The first Dragon V2 test will be a race between the pad abort later this year and the initial DragonFly helicopter drop test + propulsive assisted touchdown.

The original pad abort test was scheduled for June but the weather, KSC radar fire and other delays with CRS-3 have moved everything right.

Before the pad abort they have to clear the ORBCOMM #1 and AsiaSat launches. ORBCOMM #1 is NET June 12 and AsiaSat may fly in late June or early July. Pad abort perhaps August.

DragonFly isn't supposed to fly until F9R Dev-1 tests wind down at McGregor, and that could be soon as the F9R Dev-2 pad at SpacePort America was recently completed.

[DocM]

Summary of the DragonFly tests.

(XX) - number of flights

AGL - above ground level

Flight Profile

Flight profile refers to the take?off (or drop), flight, and landing of the launch vehicle. The flight profile for each operation type is discussed below.

Propulsive Assist (2)

For the propulsive assist test, a helicopter (an Erickson E-model or equivalent) would arrive at the McGregor test site from Waco Regional Airport. The DragonFly RLV would then be tethered to the helicopter using a cable. A maximum of 300 gallons of propellant would be loaded into the DragonFly RLV for this test. The helicopter would take off with the DragonFly RLV attached and reach an altitude up to 10,000 ft. Once at that altitude, the DragonFly RLV would be released from the tether and three main parachutes would be deployed. The engines would not fire until the vehicle descends to approximately 98 ft above ground level (AGL). The engines would fire for approximately 5 seconds, and the RLV would make a powered landing. This type of operation would last approximately 30 minutes from helicopter take-off to DragonFly RLV landing. The test would be designed so that almost all fuel on board is used prior to landing. All fuel valves would shut automatically and retain any residual fuel in the capsule.

Full Propulsive (2)

Landing For the full propulsive landing test, a helicopter (an Erickson E?model or equivalent) would arrive at the McGregor test site from Waco Regional Airport. The DragonFly RLV would then be tethered to the helicopter. A maximum of 300 gallons of propellant would be loaded into the DragonFly RLV for this test. The helicopter would take off with the DragonFly RLV attached and reach an altitude up to 10,000 ft. Once at that altitude, the DragonFly RLV would be released from the tether. There would be a period of free fall and then the engines would fire for approximately 5 seconds and the RLV would make a powered landing. This type of operation would last approximately 30 minutes from helicopter take?off to DragonFly RLV landing.

Propulsive Assist Hopping (8)

Approximately 400 gallons of propellant would be loaded into the DragonFly RLV for this test. During a propulsive assisted hop test, the DragonFly RLV would launch from a launch pad and ascend to approximately 7,000 ft AGL (firing engines for 12.5 seconds). Two parachutes would be deployed for the descent, the engines would fire for 12.5 seconds, and the RLV would make a powered landing on the launch pad. This operation would last approximately 60 seconds.

Full Propulsive Hopping (18)

Approximately 400 gallons of propellant would be loaded into the DragonFly RLV for this test. During a full propulsive hop test, the DragonFly would launch from a launch pad and ascend to approximately 7.000 feet AGL (firing engines for approximately 12.5 seconds). The engines would then throttle down in order to descend (firing engines for an additional 12.5 seconds), and the RLV will make a powered landing on the launch pad. This operation would last approximately 60 seconds.

[PaulRocket]

Now that the tests for the dragon v2 at the cape and at vandenberg are scheduled, will we see tests before that at mcgregor? And with the launch abort, will it be a propulsive landing?

[flyingskippy]

I believe the Draco's use all their propellant for the abort and dragon will splash down in the ocean under parachute.

[DocM]

Launch aborts use all the onboard propellants, about 1,650 kilograms of monomethyl-hydrazine and nitrogen tetroxide, in 5 seconds (!!). They land under the chutes and into the drink. A bit shaken, but not stirred ;)

From a dead stop to full throttle (~16,400 lbs thrust) is about 100 milliseconds. Now double it as the engine pods have 2 SD's each. 4 pods per Dragon V2. Imagine that on the back of your Batmobile.

What's amazing about the SuperDraco engine is that it can throttle down to under 20%, guesses are as low as 12%, and even do rapid pulsing. Most engines suffer from flow separation when throttled below 60-80-% throttle.

[PaulRocket]

The SD engine is amazing. Will we see test at mcgregor before the launch abort in nov?

[DocM]

Very possible, but FAA hasn't issued the permit for it to fly yet and it's tests are for propulsive landings, not aborts. Different flight regimes.

The draft EIS coming put in May is only part of the process. The final EIS has to be posted, then there's a mandatory waiting period (30 days) for public comments. Then they can apply for a flight permit. FAA has been quick on those so far.

Just checked the FAA and no final EIS or permit yet.

[PaulRocket]

So much exciting stuff coming up... Can't wait!

[DocM]

Quite a list,

F9R Dev 1&2 flights

Dragon V2 pad & flight abort

DragonFly landing tests (numerous)

F9R landings, on barge and ground

Falcon Heavy Reusable (FHR bring built NOW)

etc.

Plus the manifest where they're shooting for 30 day gaps but for the last 2 are a lot closer.

Next launch is AsiaSat 6 on the 26th, 2 in one calendar month.

[flyingskippy]

How many Gs are they expecting on an abort and a landing? I would assume somewhere around 3 Gs for the pad test, even more for a mid launch abort, and 5 or 6 for the landing.

[DocM]

Aborts will hit 8+ G's. Not too bad as Soyuz does about 16.

From data in the DragonFly EIS and elsewhere,

Re-entries are passively stable, though the avionics can steer it. Dragons have deorbited then landed about 800 meters from their recovery ships under parachutes only.

At sea with parachutes only it'll land at about 11~12 m/s compared to 2-3 times that for Apollo.

For propulsive landings the SD's are tested at about 2,150 meters.

Propulsive landings, straight or under parachute, will be like the hoverslams F9R Dev-1 does; it reaches 0 m/s just as its altitude hits 0 m.

A land touchdown under parachutes only is only if all the SD's fail and is estimated at 2.5 G's. The legs have massive shock absorption ability, and the back 2 hit first being closer together & attached to reinforced structures. Then the fronts impact and it settles.

If 1-2 SD's fail it can still do a propulsive landing.

If more than 2 SD's fail but opposed engines still work they can still do a propulsive under parachutes, and they're fired out of a mortar.

If everything electronic goes to hell in a handbasket, the parachute mortar can be mechanically fired by the crew.

All of this failing at once is extremely unlikely, and being pressure fed hypergolic thrusters the SD's should be more reliable than the parachutes.

[flyingskippy]

Oh wow I was way off. Soyuz does 16 Gs?

[DocM]

Yup, at least that's about the middle of its range. Only fired once, Soyuz T-10-1 on September 26, 1983. The launcher caught fire and the LAS carried the crew to safety. Estimated at 14 to 17 G's.