Author Topic: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION  (Read 624309 times)

Offline QuantumG

  • Senior Member
  • *****
  • Posts: 9226
  • Australia
  • Liked: 4464
  • Likes Given: 1101
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #780 on: 10/08/2012 11:24 pm »
I looked around and it appears that the OG-2 has a deltav capability of 140 m/s.  From what I can tell the with a planned orbit of 350 x 700 km it was going to take about 110m/s to circularize at 700km.  With only 140 m/s to use there is no way they can make it to the desired orbit. 

This was no ordinary OG-2. They were planning to circularize their own orbit in the nominal flight plan.
Human spaceflight is basically just LARPing now.

Online GalacticIntruder

  • Full Member
  • ****
  • Posts: 509
  • Pet Peeve:I hate the word Downcomer. Ban it.
  • Huntsville, AL
  • Liked: 244
  • Likes Given: 69
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #781 on: 10/08/2012 11:25 pm »
Hitchhikers might not always get to their ideal destination.

Secondary means sacrificed if something arises that threatens the primary, in this case Dragon/ISS.

Legal Rules of the road. Good for NASA, bad for SpX and Orbcomm. If this indeed is the case, lawyers scrapped a satellite, I would be PO'd.
« Last Edit: 10/08/2012 11:28 pm by GalacticIntruder »
"And now the Sun will fade, All we are is all we made." Breaking Benjamin

Offline upjin

  • Full Member
  • *
  • Posts: 160
  • Liked: 3
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #782 on: 10/08/2012 11:27 pm »
Can anybody make an educated guess on the orbit that the ORBCOMM's prototype OG-2 could possibly get to?

And at this point it can't be said that SpaceX failed in regards to the OG-2 prototype, because it's not clear what it can't do at the lower orbit.  It might be that it can complete all of it's tests at the lower orbit, or at least most of them and the important ones.

I looked around and it appears that the OG-2 has a deltav capability of 140 m/s.  From what I can tell the with a planned orbit of 350 x 700 km it was going to take about 110m/s to circularize at 700km.  With only 140 m/s to use there is no way they can make it to the desired orbit. 


Thanks.  What ORBCOMM's corrective actions are and how much they can accomplish based on their original plans, would be reflective of how much not reaching the desired orbit was a problem.

It may be that the best way to view the present SpaceX launch is as mostly successful, with some significant issues. 

« Last Edit: 10/08/2012 11:29 pm by upjin »

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 35960
  • Cape Canaveral Spaceport
  • Liked: 18335
  • Likes Given: 397
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #783 on: 10/08/2012 11:36 pm »

in general

Jim... in general, how can one determine the amount of fuel left in a stage that is in free flight..?


Burn time or delta V are some of the ways.  Vehicles like Centaur have PU systems and know what is in the tanks.  BTW, some vehicles, like Centaur, are never in "free flight", they have settling thrusters firing almost all the time.  Watch the animated coast footage of an Atlas V or Delta IV next time and you will see what I mean.

Offline cleonard

  • Full Member
  • **
  • Posts: 212
  • Liked: 34
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #784 on: 10/08/2012 11:37 pm »
Can anybody make an educated guess on the orbit that the ORBCOMM's prototype OG-2 could possibly get to?

And at this point it can't be said that SpaceX failed in regards to the OG-2 prototype, because it's not clear what it can't do at the lower orbit.  It might be that it can complete all of it's tests at the lower orbit, or at least most of them and the important ones.

I looked around and it appears that the OG-2 has a deltav capability of 140 m/s.  From what I can tell the with a planned orbit of 350 x 700 km it was going to take about 110m/s to circularize at 700km.  With only 140 m/s to use there is no way they can make it to the desired orbit. 

Do you have a source for that?
I believe they are required to keep 18  m/s for end of life disposal, so yes, they are out of luck if you are correct.

Nothing 100% definitive by any means.

I found it mentioned here on NSF in another thread and a pdf that looks like it is from Sierra Nevada from a presentation in 2009. 
http://www.responsivespace.com/Papers/RS7/SESSIONS/Session%20III/3001_Mosher/3001C.pdf

Offline Avron

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 4930
  • Liked: 156
  • Likes Given: 159
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #785 on: 10/08/2012 11:49 pm »
Playing spot the parts.. not sure if this has been completely played out yet...

My guess.. [ Images sourced from NSF :)]

Offline Norm38

  • Full Member
  • ****
  • Posts: 1678
  • Liked: 1253
  • Likes Given: 2262
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #786 on: 10/09/2012 12:01 am »
I've read through this entire thread, and as far as I'm concerned, SpaceX is fully justified to launch the next F9 without any changes while they work on the issue.  Why?  TWA Flight 800.

Now if Flight 800, instead of exploding, had merely blown out a section of fusilage and vented the center tank, and if the crippled 747 had completed its mission and landed safely with no loss of life...
AND if all 747s were then grounded and inspected and upgraded before ever being allowed to fly again, THEN SpaceX could resonably be expected to behave in a similar fashion.

But that never happend.  A 747 exploded for no good reason, 400 people died, and the 747 fleet was never grounded.  They were not inspected in a timely fashion, and it was 12 years later (2008) before final concensus was reached on a corrective action, with passengers flying unprotected the entire time.  Unmodified 747s with potential fatal defects continue to fly thousands of passengers every day.

When Flight 800 exploded there were probably a dozen loaded 747s around the world waiting for takeoff.  None of the passengers were informed they may be sitting on a bomb, none were given a choice to change aircraft.  Someone rolled the dice and gambled thousands of lives, because at that time in 1996 there was no indication that all 747s didn't have the same defect.  There was no indication that every other 747 wouldn't do the exact same thing.

There is a glaring double standard at work here which has never made an ounce of sense.  Boeing never grounded the 747 which exploded, so why should SpaceX ground the F9 which didn't?  Per established aerospace operating practice, SpaceX can launch the exact same unmanned rocket again while they work on the problem and consider this an isolated incident.  They can implement their resolution sometime in 2024.

Unless someone can explain why bags of M&Ms and clean underwear are more deserving of protection than living breathing human beings.


Offline Avron

  • Canadian Member
  • Senior Member
  • *****
  • Posts: 4930
  • Liked: 156
  • Likes Given: 159

Offline cordor

  • Full Member
  • *
  • Posts: 166
  • Liked: 0
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #788 on: 10/09/2012 12:05 am »
Hitchhikers might not always get to their ideal destination.

Secondary means sacrificed if something arises that threatens the primary, in this case Dragon/ISS.

Legal Rules of the road. Good for NASA, bad for SpX and Orbcomm. If this indeed is the case, lawyers scrapped a satellite, I would be PO'd.

I think orbcomm knew what they paid for. 1e was 8.5M per launch(?), i guess now is 10M. on the other hand, i bet spacex is offering basement price for secondary payload right now, could be as low as 2~3M.

There are ways to lower satellite launch cost. Go reusable is one way, but it's not going to happen in the next few years. 2, FH does lower price per pound a lot and ready to launch next year. but first, spacex really need to master  how to do one launch multiple payload.  Secondary payloads on F9 give them chances to practice.

Offline jcm

  • Senior Member
  • *****
  • Posts: 3434
  • Jonathan McDowell
  • Somerville, Massachusetts, USA
    • Jonathan's Space Report
  • Liked: 1027
  • Likes Given: 645
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #789 on: 10/09/2012 12:09 am »
Can anybody make an educated guess on the orbit that the ORBCOMM's prototype OG-2 could possibly get to?

And at this point it can't be said that SpaceX failed in regards to the OG-2 prototype, because it's not clear what it can't do at the lower orbit.  It might be that it can complete all of it's tests at the lower orbit, or at least most of them and the important ones.

I looked around and it appears that the OG-2 has a deltav capability of 140 m/s.  From what I can tell the with a planned orbit of 350 x 700 km it was going to take about 110m/s to circularize at 700km.  With only 140 m/s to use there is no way they can make it to the desired orbit. 

Do you have a source for that?
I believe they are required to keep 18  m/s for end of life disposal, so yes, they are out of luck if you are correct.

Nothing 100% definitive by any means.

I found it mentioned here on NSF in another thread and a pdf that looks like it is from Sierra Nevada from a presentation in 2009. 
http://www.responsivespace.com/Papers/RS7/SESSIONS/Session%20III/3001_Mosher/3001C.pdf

Thanks
Hmm, the flyer on SNC's site seems to be 2011 and says 70 m/s - it may really be older.
-----------------------------

Jonathan McDowell
http://planet4589.org

Offline cleonard

  • Full Member
  • **
  • Posts: 212
  • Liked: 34
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #790 on: 10/09/2012 12:12 am »
I've read through this entire thread, and as far as I'm concerned, SpaceX is fully justified to launch the next F9 without any changes while they work on the issue.  Why?  TWA Flight 800.

Now if Flight 800, instead of exploding, had merely blown out a section of fusilage and vented the center tank, and if the crippled 747 had completed its mission and landed safely with no loss of life...
AND if all 747s were then grounded and inspected and upgraded before ever being allowed to fly again, THEN SpaceX could resonably be expected to behave in a similar fashion.

But that never happend.  A 747 exploded for no good reason, 400 people died, and the 747 fleet was never grounded.  They were not inspected in a timely fashion, and it was 12 years later (2008) before final concensus was reached on a corrective action, with passengers flying unprotected the entire time.  Unmodified 747s with potential fatal defects continue to fly thousands of passengers every day.

When Flight 800 exploded there were probably a dozen loaded 747s around the world waiting for takeoff.  None of the passengers were informed they may be sitting on a bomb, none were given a choice to change aircraft.  Someone rolled the dice and gambled thousands of lives, because at that time in 1996 there was no indication that all 747s didn't have the same defect.  There was no indication that every other 747 wouldn't do the exact same thing.

There is a glaring double standard at work here which has never made an ounce of sense.  Boeing never grounded the 747 which exploded, so why should SpaceX ground the F9 which didn't?  Per established aerospace operating practice, SpaceX can launch the exact same unmanned rocket again while they work on the problem and consider this an isolated incident.  They can implement their resolution sometime in 2024.

Unless someone can explain why bags of M&Ms and clean underwear are more deserving of protection than living breathing human beings.



That's not really a valid comparison.  At the time of flight 800 countless thousands of safe 747 flights had occurred.  The Falcon 9 1.0 has a total of four flights. 

While I do in a way agree, I am also sure that SpaceX is working really hard to understand exactly what happened yesterday.  If they find something to fix, they will fix it before the next flight. 

Offline Kaputnik

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 3018
  • Liked: 685
  • Likes Given: 729
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #791 on: 10/09/2012 12:12 am »
There is a glaring double standard at work here which has never made an ounce of sense.  Boeing never grounded the 747 which exploded, so why should SpaceX ground the F9 which didn't?

If the fourth flight of a 747 had suffered a significant anomaly, the fifth flight would not have gone up until the cause had been identified and rectified.
If one in every 40 aircraft engines failed in flights, I for one would not get on the plane until they had found out why, and done something about it.

Aircraft are produced and flown on a scale that completely dwarfs LVs.
« Last Edit: 10/09/2012 12:13 am by Kaputnik »
"I don't care what anything was DESIGNED to do, I care about what it CAN do"- Gene Kranz

Offline jcm

  • Senior Member
  • *****
  • Posts: 3434
  • Jonathan McDowell
  • Somerville, Massachusetts, USA
    • Jonathan's Space Report
  • Liked: 1027
  • Likes Given: 645
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #792 on: 10/09/2012 12:17 am »

It may be that the best way to view the present SpaceX launch is as mostly successful, with some significant issues. 




Agreed. I'm trying to quantify that to have a metric that I can apply fairly
to other companies' launches. I'm come up with the following strawman scheme, and welcome comments:

 Primary payloads reach some orbit and separate from LV -  30 percent
 Primary payload orbit is usable, not necessarily perfect      -  25
 Primary payload orbit is as planned (within quoted sigmas)  -  20
 Secondary payload separated in orbit -                              10
  Secondary payload orbit usable -                                     10
  Secondary payload orbit as planned -                                 5

by this metric, the Falcon 9 launch scores 85 percent

For a launch with no secondary payloads, add the corresponding secondary scores to the primary, so 40/35/25

For a launch with multiple primary payloads, divide scores evenly


one might tweak this to cover cases where the LV damages the
satellite in some way - limited damage, subtract 20 percent,
satellite inoperable scores same as failure to orbit (i.e. total 0)
-----------------------------

Jonathan McDowell
http://planet4589.org

Offline johnbellora

  • Member
  • Posts: 2
  • Liked: 0
  • Likes Given: 0
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #793 on: 10/09/2012 12:21 am »
the only thing at this point is they are going to try to do is change the orbit to more of a circular orbit which will buy a few months of operation. Right now it is in an elliptical orbit. They are going to try to use the small amount of remaining fuel to do this. If it is not sucessfull then it will plummet in a few weeks. if sucessfull then maybe three months. evidently its average height is about what the space station is. Not good enough. The Orbcomm is working so well they had to attenuate it. it is overloading the system

Offline corrodedNut

  • Full Member
  • ****
  • Posts: 1542
  • Liked: 216
  • Likes Given: 133
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #794 on: 10/09/2012 12:35 am »
About the damage done by the accident, did someone noticed that the view we have of the octopus manifold shows no signs of damage ?
It's few inches away from the engines.

I did notice, was going to make the same post. Looks remarkably clean in there, doesn't it?

When I saw it live (and knowing nothing of the anomaly yet) I thought to myself: "there's a lot less exhaust circulating in here than last time".

Now I'm thinking it's that way because either the kevlar shields and thermal protection work really well...or the engine compartment has extra "ventilation".

Online Chris Bergin

Hi John -

 Welcome to the site's forum. We've got some raw notes - matching what you're saying - and I'm about to start drafting up what we have on all of this.

 What we didn't have is potential outcomes for this, so appreciate your insight.
Support NSF via L2 -- Help improve NSF -- Site Rules/Feedback/Updates
**Not a L2 member? Whitelist this forum in your adblocker to support the site and ensure full functionality.**

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 35960
  • Cape Canaveral Spaceport
  • Liked: 18335
  • Likes Given: 397
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #796 on: 10/09/2012 12:38 am »

Unless someone can explain why bags of M&Ms and clean underwear are more deserving of protection than living breathing human beings.


Because the TWA 800 analogy is not applicable

Offline Chris-A

  • Member
  • Full Member
  • ****
  • Posts: 563
  • Liked: 28
  • Likes Given: 33
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #797 on: 10/09/2012 12:38 am »
Playing spot the parts.. not sure if this has been completely played out yet...

My guess.. [ Images sourced from NSF :)]

The F9 Merlin configuration does not have those panels.

Offline cygnusx112

Last night they had a fire on the pad and the announcer mentioned it as being “normal”? Does anyone know what the fire was and if this is normal?

Offline jcm

  • Senior Member
  • *****
  • Posts: 3434
  • Jonathan McDowell
  • Somerville, Massachusetts, USA
    • Jonathan's Space Report
  • Liked: 1027
  • Likes Given: 645
Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #799 on: 10/09/2012 12:46 am »
the only thing at this point is they are going to try to do is change the orbit to more of a circular orbit which will buy a few months of operation. Right now it is in an elliptical orbit. They are going to try to use the small amount of remaining fuel to do this. If it is not sucessfull then it will plummet in a few weeks. if sucessfull then maybe three months. evidently its average height is about what the space station is. Not good enough. The Orbcomm is working so well they had to attenuate it. it is overloading the system

That's great information, thanks for sharing it.
BTW, as far as I can see, average height is only about 260 km while station is at 400 km.
-----------------------------

Jonathan McDowell
http://planet4589.org

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1