SpaceX Successfully Tests Crew Dragon Landing Parachutes

SpaceX successfully tested out the parachute system it plans to use to land its Crew Dragon spaceship safely back on Earth today. By using a "mass simulator," SpaceX was able to replicate the weight and shape of the spacecraft. According to NASA, "Later tests will grow progressively more realistic to simulate as much of the actual conditions and processes the system will see during an operational mission."

The goal of the test was to evaluate the four main parachutes, but this test did not include the "drogue chutes" the full landing system will utilize. The aim is for the spacecraft to splash safely into the ocean carried down by parachutes to reduce its speed. Eventually, SpaceX intends for the spacecraft to land upright on solid ground by utilizing eight SuperDraco propulsion engines. SpaceX successfully landed its Falcon 9 rocket at Cape Canaveral in December. Earlier this month, a SpaceX Falcon 9 exploded upon landing on a drone ship.

Comments

details, details

[xeno]

"SpaceX Falcon 9 exploded upon landing on a drone ship" is not quite accurate...

In December, SpaceX lanuched a Falcon9 rocket with a series of successes: successful launch of the whole rocket, successful landing (on land) of stage1, successfully reaching orbit on stage2, insertion of 11 satellites into sustainable orbits, etc etc. It was a good day for them.

A couple weeks ago, they launched another (slightly older design) Falcon9, *mostly* successfully: Launch was good, stage 1 separation and return to landing spot (this time on a modified barge) was successful, stage 2 was good, payload was good, etc etc. The failure was that immediately after landing on the barge, the stage 1 fell over because one of the landing legs failed to lock. So yeah, the stage 1 exploded... /after/ successfully landing on a tiny dot in the middle of the ocean. These guys are making huge strides forward in reusable spaceflight, so it's hardly fair to dismiss the whole thing as "exploded upon landing" because of a mechanical leg failure after the damn thing landed and powered off.

Re:Who is whipslash?

[whipslash]

My name is Logan Abbott and I am part of the team that purchased Slashdot and SourceForge from DHI. I've been a long time reader of Slashdot, but I'm getting my bearings as a first time editor. It is true that Slashdot was sold to BIZX. Contrary to one of the previous comments, BIZX is not an "SEO company" (granted, our corporate site isn't the coolest thing. Note to self: get that thing updated). BIZX is a small web media company based out of San Diego, CA that's been around for 16 years.

I've been involved with the Internet my whole life so I'm not shocked by the comments I'm getting as a new editor. Heck, posting anonymously I'd probably be doing the same thing in your shoes (all is fair in love and war and the Internet). If anything, it shows the dedication this community has in keeping Slashdot relevant and true to its origins. I have a background in Drupal and PHP, so I'm still getting the hang of this Perl thing.

As for the future of the site, yes we will address it. There are a lot of moving parts in assuming control of two huge sites so we will address it as soon as we can. We're going to listen to you guys as to the future of the site. I don't mean listen like we're going to roll out a full new version of the site, and then field complaints from loyal users like the last time Slashdot was changed. I mean we are actually going to listen. You're not going to wake up tomorrow to a Slashdot you don't recognize. Our immediate plan is to give Slashdot the support it needs to be the most successful and vibrant technology news and discussion community as possible. There might be some hiccups along the way, but I can take the heat and very much welcome all of your feedback. To be clear, we want to continue improving with the true spirit of Slashdot in mind.

There is more information here for the time being: http://fossforce.com/2016/01/s...

Happy to answer more questions.

SpaceX does everything in fours.

[Michael Woodhams]

SpaceX love fourfold symmetry: octagonal layout of stage 1 rockets (plus one central, for 9 total). Four landing legs. Four steering fins at the top of stage I. Four pairs of "super Draco" landing/abort rockets on the Dragon. And now, four chutes.

Staged chute deployment - how's that work?

[Michael Woodhams]

There is a thing that these chutes do, where on initial deployment the open aperture of the chute is quite small, and the chute looks rather like a sausage. Then later on, the chute abruptly opens fully, and looks like a hemisphere. (The transition wasn't shown in the video in TFA, but I've seen it elsewhere and it is also simulated in Kerbal Space Program.)

How is this achieved? Is it some clever aerodynamics where the chute has two stable configurations and a 'catastrophic' transition? Is there some rope which constrains the aperture early on and then is somehow severed to allow fully deployment?

(I understand why - the first configuration slows the payload sufficiently so that the chute is not torn apart when it fully deploys. "How" is what I don't know.)

Re:Staged chute deployment - how's that work?

[Anonymous Coward]

In a typical, human-carrying parachute, there's a gizmo called the slider that handles this.
The point (if it isn't obvious), is two fold: (1) minimize stresses on the parachute and risers
during the parachute's opening/deceleration; and (2) minimize the stresses on the human/cargo
that would be induced by decelerating from terminal velocity (~120 MPH IAS) to ~10 MPH.

The slider, on modern "square" chutes, is a rectangular piece of cloth with grommets on
each corner, through which the parachute's risers run. The slider is run all the way up
the risers to the parachute, and packed that way. When the rip-cord is pulled, a spring
ejects a drogue parachute (for single person parachutes only; tandem parachutes work
differently), which pulls out the canopy. The canopy then tries to inflate, but the riser
prevents it from expanding to its full size. As the canopy slows, it inflates, and the
increasing size gives it more leverage/angle on the risers to force the slider downwards,
allowing the canopy to expand more.

Eventually the slider reaches a mechanical stop on the risers (usually just above the
parachutist's head), and the canopy is fully deployed.

Even with the slider, the canopy opening is quite a jarring event.

Re:Staged chute deployment - how's that work?

[DerekLyons]

How is this achieved? Is it some clever aerodynamics where the chute has two stable configurations and a 'catastrophic' transition? Is there some rope which constrains the aperture early on and then is somehow severed to allow fully deployment?

The process is called reefing.
 
Rings of cable woven into the parachute hold it in the "sausage" shape, they're then cut with explosive cutters (or released by explosive releases) and the parachute expands to it's final configuration.

Re:I don't get it.

[jfdavis668]

The pad abort test didn't need high speed parachutes. The in flight abort test does. The pad abort test landing in water, so it didn't need the hover capability. Future attempts will be made on land. These tests are being conducted to prepare for the MaxQ in flight abort test.