Previous Thread
Next Thread
Print Thread
Rate This Thread
Hop To
Page 1 of 2 1 2
#4060246 - 01/06/15 01:55 AM SpaceX going for a first ever tomorrow  
Joined: Jan 2001
Posts: 18,549
piper Offline
Veteran
piper  Offline
Veteran

Joined: Jan 2001
Posts: 18,549
Raleigh,NC
Pretty darn cool if they can pull this off.

http://www.nbcnews.com/science/space/spa...-online-n280031

Inline advert (2nd and 3rd post)

#4060251 - 01/06/15 02:02 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jan 2001
Posts: 25,138
RSColonel_131st Offline
Lifer
RSColonel_131st  Offline
Lifer

Joined: Jan 2001
Posts: 25,138
Vienna, 2nd rock left.
Crazy stunt. I suppose a land-based platform wouldn't be reachable from the trajectory needed...

#4060254 - 01/06/15 02:12 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jul 2009
Posts: 9,620
CyBerkut Online content
Administrator
CyBerkut  Online Content
Administrator
Hotshot

Joined: Jul 2009
Posts: 9,620
Florida
I'd guess it's more due to being a safety precaution until they have sufficiently proven they can hit their landing target.

#4060255 - 01/06/15 02:13 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jan 2011
Posts: 1,527
WileECoyote Offline
Member
WileECoyote  Offline
Member

Joined: Jan 2011
Posts: 1,527
Argentina
Holy crap! That's way cool.


When you're feeling sad, just remember that somewhere in the world, there's someone pushing a door that says "pull".
#4060258 - 01/06/15 02:20 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jan 2001
Posts: 18,549
piper Offline
Veteran
piper  Offline
Veteran

Joined: Jan 2001
Posts: 18,549
Raleigh,NC
It's not a crazy stunt. They have proven the technology under much more controlled environment (and altitude).
I'm sure the out-to-sea is a safety precaution, but I would worry about unpredictable surface winds..

I wish them well.

#4060261 - 01/06/15 02:25 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jan 2010
Posts: 8,700
Peally Offline
Hotshot
Peally  Offline
Hotshot

Joined: Jan 2010
Posts: 8,700
Wisconsin, USA
They're our main space exploration right now, more power to them I hope it goes well.


Scully: Victim died of multiple stab wounds.
Mulder: *throws her a file* Ever heard of the knife alien?
#4060297 - 01/06/15 06:25 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Nov 2004
Posts: 19,794
adlabs6 Offline
Veteran
adlabs6  Offline
Veteran

Joined: Nov 2004
Posts: 19,794
Tracy Island
Fantastic stuff. I hope it works!


WARNING: This post contains opinions produced in a facility which also occasionally processes fact products.
#4060300 - 01/06/15 06:52 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jun 2011
Posts: 2,764
Weaponz248 Offline
Hail To The King Baby!!
Weaponz248  Offline
Hail To The King Baby!!
Senior Member

Joined: Jun 2011
Posts: 2,764
Statesboro GA USA
Awesome! I hope it works.


Quick question, According to this picture,



the reentry is basically 90 degrees to earth, I thought you had to enter the atmosphere at a different angle.


XBOX Live Tag/Steam/PSN: Weaponz248

#4060316 - 01/06/15 08:59 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jun 2010
Posts: 1,181
DaBBQ Offline
Bug Stompe....Quisling
DaBBQ  Offline
Bug Stompe....Quisling
Member

Joined: Jun 2010
Posts: 1,181
Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path.

#4060327 - 01/06/15 10:51 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Dec 2000
Posts: 6,968
Jayhawk Offline
Silastic Armorfiend
Jayhawk  Offline
Silastic Armorfiend
Hotshot

Joined: Dec 2000
Posts: 6,968
Docking Bay 94
Pfft. Blofeld could do this already in the 1960's, and land the rocket inside a volcano.

jamesbond


Why men throw their lives away attacking an armed Witcher... I'll never know. Something wrong with my face?
#4060353 - 01/06/15 12:56 PM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jul 2009
Posts: 9,620
CyBerkut Online content
Administrator
CyBerkut  Online Content
Administrator
Hotshot

Joined: Jul 2009
Posts: 9,620
Florida
http://www.spacex.com/webcast/
Quote:
Launch Update
During the terminal count engineers observed drift on one of the two thrust vector actuators on the second stage that would likely have caused an automatic abort. Engineers called a hold in order to take a closer look. SpaceX is scrubbed for today and we are now targeting launch on Jan. 9th at 5:09am ET.




#4060360 - 01/06/15 01:27 PM Re: SpaceX going for a first ever tomorrow [Re: DaBBQ]  
Joined: Jun 2011
Posts: 2,764
Weaponz248 Offline
Hail To The King Baby!!
Weaponz248  Offline
Hail To The King Baby!!
Senior Member

Joined: Jun 2011
Posts: 2,764
Statesboro GA USA
Originally Posted By: DaBBQ
Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path.


Ah Gotcha! Thanks makes sense now.


XBOX Live Tag/Steam/PSN: Weaponz248

#4060370 - 01/06/15 01:55 PM Re: SpaceX going for a first ever tomorrow [Re: DaBBQ]  
Joined: Jan 2010
Posts: 8,700
Peally Offline
Hotshot
Peally  Offline
Hotshot

Joined: Jan 2010
Posts: 8,700
Wisconsin, USA
Originally Posted By: DaBBQ
Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path.


Air compression, not friction wink


Scully: Victim died of multiple stab wounds.
Mulder: *throws her a file* Ever heard of the knife alien?
#4060609 - 01/07/15 05:27 AM Re: SpaceX going for a first ever tomorrow [Re: Peally]  
Joined: Aug 2002
Posts: 4,010
PV1 Offline
sometime mudslinger
PV1  Offline
sometime mudslinger
Senior Member

Joined: Aug 2002
Posts: 4,010
Ladner, Wet Coast, Canada
Originally Posted By: Peally
Originally Posted By: DaBBQ
Its only high speed atmospheric friction that burns the objects. If you can keep enough fuel in the engine to keep the speed down, you could drop through at a perpendicular path.


Air compression, not friction wink

Wouldn't it be both?
I think around mach 1.3 or so friction heating
wins over air cooling for air passing over a
surface.

#4060614 - 01/07/15 06:18 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Jul 2000
Posts: 2,708
Paul Rix Offline
Senior Member
Paul Rix  Offline
Senior Member

Joined: Jul 2000
Posts: 2,708
NW of Austin, Tx
Weaponz248, if you want to learn a little bit about how space flight works (orbital mechanics, spacecraft design considerations, etc etc) in a fun and generally easy to understand format, I high recommend that you should check out Kerbal Space Program. It's surprising how much you can learn from playing it.


Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.
Carl Sagan
#4060629 - 01/07/15 08:24 AM Re: SpaceX going for a first ever tomorrow [Re: PV1]  
Joined: Dec 1999
Posts: 7,747
Ssnake Offline
Virtual Shiva Beast
Ssnake  Offline
Virtual Shiva Beast
Hotshot

Joined: Dec 1999
Posts: 7,747
Germoney
Originally Posted By: PV1
I think around mach 1.3 or so friction heating wins over air cooling for air passing over a surface.

That's nice and well but if you're entering the atmosphere from orbital velocity or even higher you're at about Mach 30. By the time you have decelerated to something comparatively benign as Mach 3 the air compression is no longer dominant, but then you have already shed 99% of your kinetic energy. So, for both the longest path of the atmospheric braking trajectory and for the overwhelming amount of kinetic energy decay air friction is a negligible factor in comparison to the heat transfer by air compression.

#4060993 - 01/08/15 04:50 AM Re: SpaceX going for a first ever tomorrow [Re: Ssnake]  
Joined: Aug 2002
Posts: 4,010
PV1 Offline
sometime mudslinger
PV1  Offline
sometime mudslinger
Senior Member

Joined: Aug 2002
Posts: 4,010
Ladner, Wet Coast, Canada
Originally Posted By: Ssnake
Originally Posted By: PV1
I think around mach 1.3 or so friction heating wins over air cooling for air passing over a surface.

That's nice and well but if you're entering the atmosphere from orbital velocity or even higher you're at about Mach 30. By the time you have decelerated to something comparatively benign as Mach 3 the air compression is no longer dominant, but then you have already shed 99% of your kinetic energy. So, for both the longest path of the atmospheric braking trajectory and for the overwhelming amount of kinetic energy decay air friction is a negligible factor in comparison to the heat transfer by air compression.

OK. But at the top end, you'll also get a larger
fraction of contribution from friction as well,
until the air gets thick enough that compression
comes in to play - you don't get compression with
scattered individual atoms. I wonder how it breaks
down; friction might be 10%, maybe 20%? There's
a lot of distance in near vacuum before you get
to the thicker stuff. I guess the distinction is
a function of the mean free path.

#4061047 - 01/08/15 11:13 AM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Dec 1999
Posts: 7,747
Ssnake Offline
Virtual Shiva Beast
Ssnake  Offline
Virtual Shiva Beast
Hotshot

Joined: Dec 1999
Posts: 7,747
Germoney
Feel free to earn yourself a degree in aerospace engineering to answer that question. Seriously - my expertise ends with the fundamental physical factors in play and estimating which one is dominant.

From what I understand, the shockwave of the hypervelocity atmospheric entry lets most of the air bypass the spacecraft in some "onion shaped" near vacuum bubble surrounded by oxygen and nitrogen plasma. Only after you reach the denser layers of the atmosphere and by the time that the capsule/spacecraft has slowed down to maybe Mach 6 or 8 you get something resembling a laminary flow that would interact with the capsule body by means of actual air friction. That's still considerable, but at least one order of magnitude less than the heat transfer from air compression for most of the reentry phase.

Originally Posted By: PV1
you don't get compression with scattered individual atoms.

You do, if you move fast enough (just think of interstellar gas jets that show turbulent behavior; even the densest jets still are what qualifies as a high grade vacuum down here).
Or, by the same token, you don't get much friction from scattered, individual atoms. But by definition the atmosphere starts where you have a measurable air pressure. And by that definition you no longer have "scattered individual atoms".

#4061054 - 01/08/15 11:36 AM Re: SpaceX going for a first ever tomorrow [Re: Paul Rix]  
Joined: Jun 2011
Posts: 2,764
Weaponz248 Offline
Hail To The King Baby!!
Weaponz248  Offline
Hail To The King Baby!!
Senior Member

Joined: Jun 2011
Posts: 2,764
Statesboro GA USA
Originally Posted By: Paul Rix
Weaponz248, if you want to learn a little bit about how space flight works (orbital mechanics, spacecraft design considerations, etc etc) in a fun and generally easy to understand format, I high recommend that you should check out Kerbal Space Program. It's surprising how much you can learn from playing it.


Thanks Paul! I dont think I have played around with that for awhile. Need to check it out again. What DaBBQ said made sense to me, When I think reentry I always think space shuttle which is a glider running on empty. When he said enough fuel it clicked.


XBOX Live Tag/Steam/PSN: Weaponz248

#4062130 - 01/10/15 03:54 PM Re: SpaceX going for a first ever tomorrow [Re: piper]  
Joined: Feb 2007
Posts: 167
Rask Offline
Member
Rask  Offline
Member

Joined: Feb 2007
Posts: 167

Well the Dragon Capsule was launched succesfully into orbit and is now on it's way for a rendezvous with the ISS on Monday.

The first stage retrival was only a minor success as the stage indeed made it back to the drone ship, but it hit it too hard and was probably destroyed:

Originally Posted By: "Elon Musk"
Rocket made it to drone spaceport ship, but landed hard. Close, but no cigar this time. Bodes well for the future tho. https://twitter.com/elonmusk/status/553855109114101760


It was a good try and i bet many things can be learned from the attempt.

Well done SpaceX

Page 1 of 2 1 2

Moderated by  RacerGT 

Quick Search
Recent Articles
Support SimHQ

If you shop on Amazon use this Amazon link to support SimHQ
.
Social


Recent Topics
Carnival Cruise Ship Fire....... Again
by F4UDash4. 03/26/24 05:58 PM
Baltimore Bridge Collapse
by F4UDash4. 03/26/24 05:51 PM
The Oldest WWII Veterans
by F4UDash4. 03/24/24 09:21 PM
They got fired after this.
by Wigean. 03/20/24 08:19 PM
Grown ups joke time
by NoFlyBoy. 03/18/24 10:34 PM
Anyone Heard from Nimits?
by F4UDash4. 03/18/24 10:01 PM
RIP Gemini/Apollo astronaut Tom Stafford
by semmern. 03/18/24 02:14 PM
10 years after 3/8/2014
by NoFlyBoy. 03/17/24 10:25 AM
Copyright 1997-2016, SimHQ Inc. All Rights Reserved.

Powered by UBB.threads™ PHP Forum Software 7.6.0