Author Topic: SpaceX outlines CRS-3 landing legs plan toward first stage recovery ambitions  (Read 28491 times)

Online Chris Bergin

Third article on the legs....but this one is built from answers we gained from SpaceX - and covers more than just CRS-3.

http://www.nasaspaceflight.com/2014/02/spacex-crs-3-landing-legs-plan-first-stage-recovery-ambitions/



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To collate all the recent resources (lots of links, but it provides pretty much all you need on one post):

Falcon 9 preparing to stretch her legs via Grasshopper trials:
http://www.nasaspaceflight.com/2014/02/falcon-9-stretch-legs-grasshopper-trials/

CRS-3 Falcon 9 first stage to sport legs and attempt soft splashdown:
http://www.nasaspaceflight.com/2014/02/crs-3-falcon-9-first-stage-sport-legs-attempt-soft-splashdown/

Previous main thread for the above article:
http://forum.nasaspaceflight.com/index.php?topic=34065.0

--

L2 SpaceX:

Falcon 9 Reusable (F9R-Dev1) Photos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1155703#msg1155703

Better Falcon 9 Reusable (F9R-Dev1) Photos - with legs:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1156035#msg1156035

Grasshopper 1 and 2 - and Texas Site - Videos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1156491#msg1156491

New Status on FH, F9-R and Raptor MCT via Tom Mueller (19th of Feb):
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1162065#msg1162065

Falcon CRS-3 with Legs notes:
http://forum.nasaspaceflight.com/index.php?topic=31562.msg1161997#msg1161997

Falcon 9 Reusable (F9R-Dev1) with legs - Feb 22 photos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1163399#msg1163399

CRS-3 Reusable SpaceX Quotes - and Grasshopper notes:
http://forum.nasaspaceflight.com/index.php?topic=31562.msg1165068#msg1165068
« Last Edit: 03/01/2014 01:09 PM by Chris Bergin »

Offline Lars_J

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A great article, Chris!

It's nice to get confirmation about when the legs are going to be extended - and if it is 10 seconds into the landing burn, that must be *very* close to the surface. I suppose the acceleration upwards will help the legs deploy and lock.

Offline AndyX

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Great write up again!

And one of SpaceX's investors mentioned it on Twitter! :)

bill lee ‏@westcoastbill  16m
cant wait for this “@NASASpaceflight: @SpaceX outline CRS-3 landing legs plan toward first stage recovery http://www.nasaspaceflight.com/2014/02/spacex-crs-3-landing-legs-plan-first-stage-recovery-ambitions/#.UxFawTDIPu8.twitter

Online Chris Bergin

Thanks chaps - and a hat tip to QuantumG for providing a very helpful subedit assist for a very tired me! (speaking of which, I'm outta here! ;D)

Bill Lee's mentioned us a good number of times per SpaceX articles. So's Elon's mum! :)

Offline RocketmanUS

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Might not be this flight , however it very well could be this year for a successful water landing test.

Offline Elmar Moelzer

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Great article Chris! Nice to see some confirmation of speculation in the forum. Some new information too. Any word how close back to the launch site, the boostback will get the stage this time?

Offline Dave G

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Thanks Chris!  Another great article.

One thing still bothers me.  SpaceX says they are aiming for fully reusable, but there doesn't seem to be any plan for reusing the Dragon trunk:
http://www.spacex.com/news/2013/03/26/dragon-trunk

Quote
The trunk, a riveted aluminum structure, is 2.8 meters (9.2 feet) tall and 3.66 meters (12 feet) wide. The trunk also houses the radiator which is integral to the trunk structure, with the ability to reject up to 3kW of heat.

Fairings housing Dragon’s solar arrays—two arrays, each composed of four panels—are attached to the outside of the trunk.  The arrays produce more than 5 kilowatts of power, and surplus power recharges Dragon’s batteries for the periods when it is in darkness.

This sounds like a fairly expensive piece.  How can they say fully reusable when they throw this away every time?

Offline IRobot

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This sounds like a fairly expensive piece.  How can they say fully reusable when they throw this away every time?
I think Elon said they might use batteries instead of the expensive solar panels. At least for the crewed version of Dragon.
« Last Edit: 03/01/2014 10:41 AM by IRobot »

Offline NovaSilisko

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Well, the Falcon 9 is planned to be fully reusable, and the trunk is just part of one of its payloads ;)

The payload fairings for the cargo version on the other hand, I wonder how much they cost to manufacture? Presumably not much.

Offline Lar

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Trunk reusability is probably off topic for this thread. Try the general Falcon/Dragon thread. I didn't trim anything. Yet.

http://forum.nasaspaceflight.com/index.php?topic=33598.0

And, another boffo article, Chris! :)
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Online Zardar

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So, the landing burn must be at least 10 seconds long, plus some more time to deploy (and verify deployment) of the landing legs? (which is the critical engineering test for this attempt)
How much fuel will a burn that long take, and with a burn that long will it have passed the zero vertical velocity point well above sea level and be accelerating upwards again - even at lowest throttle? (IANARS...)

Does that this mean that a hover slam & soft touchdown will be impossible, (unless they do a second landing burn), and that's why they only have a 30% chance stated of success?



Offline clongton

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Does that this mean that a hover slam & soft touchdown will be impossible, (unless they do a second landing burn), and that's why they only have a 30% chance stated of success?

In accordance with the incremental testing program that SpaceX has been executing there is really only one mission objective to this attempt; to demonstrate a successful deployment of the landing legs - and nothing more. They will likely attempt to recover the stage if that is deemed possible, but are fully expecting it to be lost. Soft touchdown and stage recovery are not mission objectives for this event.

Nice article Chris. BTW I was thinking as I was reading this that there literally is nowhere else on earth I know of where I, or anyone else for that matter, can go to get up-to-the-minute accurate news of space-related events and plans like this article described. NSF is truly a world-class place. Thank you.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline IRobot

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They will likely attempt to recover the stage if that is deemed possible, but are fully expecting it to be lost. Soft touchdown and stage recovery are not mission objectives for this event.
Carbon fiber can handle salt water, so the legs can be recovered if they are not damaged. Still, they probably don't want to risk it, as it is very hard to diagnose carbon fiber failures.

Online Chris Bergin

Thanks chaps....


Nice article Chris. BTW I was thinking as I was reading this that there literally is nowhere else on earth I know of where I, or anyone else for that matter, can go to get up-to-the-minute accurate news of space-related events and plans like this article described. NSF is truly a world-class place. Thank you.

And thanks for that! ;)

PS I've changed the headline from SpaceX outline to SpaceX outlines, as I've got to get my head around SpaceX being singular - I used to struggle with that when referencing NASA.

Offline Rocket Science

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Does that this mean that a hover slam & soft touchdown will be impossible, (unless they do a second landing burn), and that's why they only have a 30% chance stated of success?

In accordance with the incremental testing program that SpaceX has been executing there is really only one mission objective to this attempt; to demonstrate a successful deployment of the landing legs - and nothing more. They will likely attempt to recover the stage if that is deemed possible, but are fully expecting it to be lost. Soft touchdown and stage recovery are not mission objectives for this event.

Nice article Chris. BTW I was thinking as I was reading this that there literally is nowhere else on earth I know of where I, or anyone else for that matter, can go to get up-to-the-minute accurate news of space-related events and plans like this article described. NSF is truly a world-class place. Thank you.
I would a tried to add flotation bags to the stage for recovery and inspection...
"The laws of physics are unforgiving"
~Rob: Physics instructor, Aviator, Vintage auto racer

Offline Jefferson

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Third article on the legs....but this one is built from answers we gained from SpaceX - and covers more than just CRS-3.

http://www.nasaspaceflight.com/2014/02/spacex-crs-3-landing-legs-plan-first-stage-recovery-ambitions/



---

To collate all the recent resources (lots of links, but it provides pretty much all you need on one post):

Falcon 9 preparing to stretch her legs via Grasshopper trials:
http://www.nasaspaceflight.com/2014/02/falcon-9-stretch-legs-grasshopper-trials/

CRS-3 Falcon 9 first stage to sport legs and attempt soft splashdown:
http://www.nasaspaceflight.com/2014/02/crs-3-falcon-9-first-stage-sport-legs-attempt-soft-splashdown/

Previous main thread for the above article:
http://forum.nasaspaceflight.com/index.php?topic=34065.0

--

L2 SpaceX:

Falcon 9 Reusable (F9R-Dev1) Photos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1155703#msg1155703

Better Falcon 9 Reusable (F9R-Dev1) Photos - with legs:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1156035#msg1156035

Grasshopper 1 and 2 - and Texas Site - Videos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1156491#msg1156491

New Status on FH, F9-R and Raptor MCT via Tom Mueller (19th of Feb):
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1162065#msg1162065

Falcon CRS-3 with Legs notes:
http://forum.nasaspaceflight.com/index.php?topic=31562.msg1161997#msg1161997

Falcon 9 Reusable (F9R-Dev1) with legs - Feb 22 photos:
http://forum.nasaspaceflight.com/index.php?topic=33488.msg1163399#msg1163399

CRS-3 Reusable SpaceX Quotes - and Grasshopper notes:
http://forum.nasaspaceflight.com/index.php?topic=31562.msg1165068#msg1165068

Got to love SpaceX. They really are doing exciting things. Thank you for this great site that lets us in on these cool spacey things! ;D

Offline llanitedave

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I would a tried to add flotation bags to the stage for recovery and inspection...

That would be a waste of time, weight, and money.  They aren't going to use them for return to launch site, there's no reason to try to develop a new complex system that's only going to be used for a few tests.
"I've just abducted an alien -- now what?"

Online rsnellenberger

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Nice article, but I wasn't sure what I was looking at in the last picture -- is that their test area in New Mexico, or an artist's conception of what it will look like, or something else entirely? 

Online 411rocket

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Nice article, but I wasn't sure what I was looking at in the last picture -- is that their test area in New Mexico, or an artist's conception of what it will look like, or something else entirely?

I believe, that is the main building at Space Port America, with a pad shown in the background.

Offline Rocket Science

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I would a tried to add flotation bags to the stage for recovery and inspection...

That would be a waste of time, weight, and money.  They aren't going to use them for return to launch site, there's no reason to try to develop a new complex system that's only going to be used for a few tests.
They already have a source onboard for pressurization adding a few bags is no big deal for an outfit like SpaceX...
"The laws of physics are unforgiving"
~Rob: Physics instructor, Aviator, Vintage auto racer

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