Delta-IV-M+(4,2) - GPS IIF-3 - October 4, 2012 (1210UTC)

[arkaska]

"U.S. Air Force Gen. William Shelton, commander of Air Force Space Command, has ordered an “accident investigation board” to review an upper-stage thrust anomaly that occurred during the successful Oct. 4 launch of a GPS satellite aboard a United Launch Alliance (ULA) Delta 4 rocket, the service announced Oct. 11."

http://www.spacenews.com/launch/121012-shelton-investigation-delta-anomaly.html

[Prober]

"U.S. Air Force Gen. William Shelton, commander of Air Force Space Command, has ordered an “accident investigation board” to review an upper-stage thrust anomaly that occurred during the successful Oct. 4 launch of a GPS satellite aboard a United Launch Alliance (ULA) Delta 4 rocket, the service announced Oct. 11."

http://www.spacenews.com/launch/121012-shelton-investigation-delta-anomaly.html

Not surprised by this .....too much rides on the RL-10 working as advertised.

[Ben the Space Brit]

"U.S. Air Force Gen. William Shelton, commander of Air Force Space Command, has ordered an “accident investigation board” to review an upper-stage thrust anomaly that occurred during the successful Oct. 4 launch of a GPS satellite aboard a United Launch Alliance (ULA) Delta 4 rocket, the service announced Oct. 11."

http://www.spacenews.com/launch/121012-shelton-investigation-delta-anomaly.html

Not surprised by this .....too much rides on the RL-10 working as advertised.

Is there a history of problems with the RL-10B-2 specifically? I know that there was an early MECO with the RL-10A-4 on an early Atlas-V flight but I wasn't aware of any problems with the Delta-IV equivalent.

[kevin-rf]

"U.S. Air Force Gen. William Shelton, commander of Air Force Space Command, has ordered an “accident investigation board” to review an upper-stage thrust anomaly that occurred during the successful Oct. 4 launch of a GPS satellite aboard a United Launch Alliance (ULA) Delta 4 rocket, the service announced Oct. 11."

http://www.spacenews.com/launch/121012-shelton-investigation-delta-anomaly.html

Not surprised by this .....too much rides on the RL-10 working as advertised.

Is there a history of problems with the RL-10B-2 specifically? I know that there was an early MECO with the RL-10A-4 on an early Atlas-V flight but I wasn't aware of any problems with the Delta-IV equivalent.

That was traced to a leaking LH valve. I think the previous RL-10 issue was the Delta III chamber breach due to a faulty weld on flight 2 in 1999. I think prior to that it was the two failed restarts in a row in the early 1990's.

It has been a rock solid engine with a long history.

Like everyone else I am curious as to the cause.

Edit: Atlas I AC-70 and AC-71 in 1991 and 1992.

[Blackstar]

From what I've heard (and I'll admit I'm murky on the details), there is general agreement within the national security community that if they are going to invest in any rocket development in the near-term, it should be in creating a replacement for the RL-10. It's a reliable engine, but they've used up all margin and they cannot get much more out of it.

[Prober]

From what I've heard (and I'll admit I'm murky on the details), there is general agreement within the national security community that if they are going to invest in any rocket development in the near-term, it should be in creating a replacement for the RL-10. It's a reliable engine, but they've used up all margin and they cannot get much more out of it.

been designed and somewhat tested, not excuted fully.

Many directions can be taken which fork in the road to take?

[douglas100]

From what I've heard (and I'll admit I'm murky on the details), there is general agreement within the national security community that if they are going to invest in any rocket development in the near-term, it should be in creating a replacement for the RL-10. It's a reliable engine, but they've used up all margin and they cannot get much more out of it.

Do you know if there has been any consideration in the community of removing any commonality between Atlas and Delta so that an accident with one does not ground the whole fleet?

[Star One]

From what I've heard (and I'll admit I'm murky on the details), there is general agreement within the national security community that if they are going to invest in any rocket development in the near-term, it should be in creating a replacement for the RL-10. It's a reliable engine, but they've used up all margin and they cannot get much more out of it.

Do you know if there has been any consideration in the community of removing any commonality between Atlas and Delta so that an accident with one does not ground the whole fleet?

From what was posted in that thread by Dr Sowers of ULA it seems like they are looking at more commonality between the two not less.

[HIPAR]

GPS IIF-3 is usable.  Here is the official notification to NAVSTAR users:

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2012070
SUBJ: SVN65 (PRN24) USABLE JDAY 319/0033
1.     NANU TYPE: USABINIT
        NANU NUMBER: 2012070
        NANU DTG: 140038Z NOV 2012
        REFERENCE NANU: N/A
        REF NANU DTG: N/A
        SVN: 65
        PRN: 24
        START JDAY: 319
        START TIME ZULU: 0033
        START CALENDAR DATE: 14 NOV 2012
        STOP JDAY: N/A
        STOP TIME ZULU: N/A
        STOP CALENDAR DATE: N/A

2.  CONDITION: GPS SATELLITE SVN65 (PRN24) WAS USABLE AS OF JDAY 319
     (14 NOV 2012) BEGINNING 0033 ZULU.

3.  POC: CIVILIAN - NAVCEN AT 703-313-5900, http://HTTP://WWW.NAVCEN.USCG.GOV
     MILITARY - GPS OPERATIONS CENTER at http://HTTPS://GPS.AFSPC.AF.MIL/GPSOC,
DSN 560-2541,
     COMM 719-567-2541, [email protected],
http://HTTPS://GPS.AFSPC.AF.MIL
     MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
     COMM 805-606-3514, [email protected]


---  CHAS

[edkyle99]

Is there a history of problems with the RL-10B-2 specifically? I know that there was an early MECO with the RL-10A-4 on an early Atlas-V flight but I wasn't aware of any problems with the Delta-IV equivalent.

RL10B-2 failed the first time it was used, during the second Delta III mission on May 5, 1999.  The engine performed its first burn to reach a parking orbit, but failed upon restart after a coast period.  A failure investigation determined that the RL10B-2 engine's combustion chamber had burst during the restart due to defective brazing of a welded reinforcing strip. Pratt & Whitney subsequently modified its brazing process and its inspection methods.

 - Ed Kyle

[jacqmans]

3rd Boeing GPS IIF Begins Operation After Early Handover to US Air Force

Excellent satellite performance advances GPS system modernization

EL SEGUNDO, Calif., Dec. 5, 2012 -- A third Boeing [NYSE: BA] GPS IIF satellite has completed on-orbit checkout and is now part of the active 31-satellite GPS constellation, providing improved performance for both military and civilian users. GPS IIF-3, now designated SVN-65, is being operated by the 50th Space Wing's 2nd Space Operations Squadron at Schriever Air Force Base, Colo., following an Oct. 4 launch from Cape Canaveral Air Force Station in Florida.
 
"We completed the checkout and validation of SVN-65 in 22 days instead of the scheduled 30," said Col. Bernie Gruber, director of the Space and Missile Systems Center's Global Positioning Systems Directorate. "The smooth transition to operations is reflective of the solid teamwork on the part of the joint Boeing and Air Force Mission Operations team as well as a healthy satellite. Following the handover, orbital maneuvers were completed to position SVN-65 in its final location and the satellite has been set to healthy."
 
"Our focus on mission success, extending from our supplier shop floors to our program management system and quality controls, has produced a high-performing satellite ready to go to work for the GPS user community," said Craig Cooning, vice president and general manager of Boeing Space and Intelligence Systems.
 
SVN-65 joins the two Boeing GPS IIFs launched in 2010 and 2011. Together, they are strengthening and enhancing the capabilities of the constellation with improved anti-jamming and greater navigational accuracy. The addition of the third IIF also means that operators can more fully test the new third civilian L5 signal that will aid commercial airline operations and search-and-rescue missions.
 
Boeing is providing a total of 12 GPS IIFs to the U.S. Air Force, which operates the GPS network. Of the remaining nine to be delivered, six will be completed by the end of 2012 and the remaining three in 2013.
 
"Boeing has partnered with the Air Force for nearly 40 years to provide this critical resource, accumulating more than 500 years of on-orbit service since the first GPS launch in 1978," said Jan Heide, Boeing GPS IIF program director.
 

[rds100]

3rd Boeing GPS IIF Begins Operation After Early Handover to US Air Force

Boeing is providing a total of 12 GPS IIFs to the U.S. Air Force, which operates the GPS network. Of the remaining nine to be delivered, six will be completed by the end of 2012 and the remaining three in 2013.

You mean they will launch and deploy 6 more satellites in the remaining 26 days of this year? Or this is just about manufacturing, not launching?

[Galactic Penguin SST]

3rd Boeing GPS IIF Begins Operation After Early Handover to US Air Force

Boeing is providing a total of 12 GPS IIFs to the U.S. Air Force, which operates the GPS network. Of the remaining nine to be delivered, six will be completed by the end of 2012 and the remaining three in 2013.

You mean they will launch and deploy 6 more satellites in the remaining 26 days of this year? Or this is just about manufacturing, not launching?

Satellite construction

[Lurker Steve]

3rd Boeing GPS IIF Begins Operation After Early Handover to US Air Force

Boeing is providing a total of 12 GPS IIFs to the U.S. Air Force, which operates the GPS network. Of the remaining nine to be delivered, six will be completed by the end of 2012 and the remaining three in 2013.

You mean they will launch and deploy 6 more satellites in the remaining 26 days of this year? Or this is just about manufacturing, not launching?

Satellite construction

I was trying to find when the rest of these bird are scheduled to launch, and it appears from the Boeing site, that is TBD. I could only find a single GPS launch on the manifest for next year. Are they waiting for old GPS sats to reach End-Of-Life, or is there some other reason we would keep these completed GPS sats in storage for a while ?

[Jim]

They will be launched at a rate of 2-3 per year.  It is cheaper to build all the spacecraft as soon as possible and then stored them until launch vs stretching out the production to meet the launch rate.

[kevin-rf]

Well we could also argue about the benefits of on orbit storage verses terrestrial storage

[edkyle99]

Just a note for this thread, that today's ULA press release mentioned some vague details on the GPS IIF-3 Delta's RL10 failure.  It was a thrust chamber fuel leak that began during the first engine start sequence.
http://www.ulalaunch.com/site/pages/News.shtml#/126/
Quoting:
"The ULA investigation has concluded that a fuel leak occurred in a specific area of the interior of the thrust chamber, and that this leak started during the first engine start sequence.  Although the investigation into the flight data anomaly continues, all credible crossover implications from the Delta anomaly for the OTV-3 Atlas vehicle and engine system have been thoroughly addressed and mitigated, culminating in the flight clearance decision for the OTV-3 launch."

I don't know how they were able to clear the Centaur RL10. 

 - Ed Kyle

[kevin-rf]

Not to read words between the lines that are not real, but what is a thrust chamber? It is not the combustion chamber (aka Delta III flight 2), so could this be the nozzle, specifically the seal in the nozzle extension which is unique to Delta?

Before Jim beats me up and takes my rocket money. Disclaimer, I think this might be an unrealistic stretch.

[edkyle99]

Not to read words between the lines that are not real, but what is a thrust chamber? It is not the combustion chamber (aka Delta III flight 2), so could this be the nozzle, specifically the seal in the nozzle extension which is unique to Delta?

Before Jim beats me up and takes my rocket money. Disclaimer, I think this might be an unrealistic stretch.

The RL10B-2 nozzle extension is carbon-composite ablative, with no propellant circulating through so that no leaks can occur on that part.  The main part of the thrust chamber is regeneratively cooled, so it can leak.

The Atlas RL10A-4-2 engine uses a smaller nozzle extension (that is not "extendible" but is fixed) attached to a main thrust chamber that is similar to the RL10B-2 chamber, but that likely operates at lower chamber pressure.

 - Ed Kyle

[Targeteer]

Some more details on the failure investigation and results...

http://spaceflightnow.com/delta/d361/investigation.html