International Launch Services is renewing its push to capture more satellite-launch business from NASA, a market that Boeing has had largely to itself in recent years with its Delta 2 rocket.

According to industry officials, the Lockheed Martin-affiliated launch services provider sees an opportunity in the impending loss of Boeingโ€™s other main source of Delta 2 business, launching GPS satellites for the U.S. Air Force. The Air Force is shifting GPS missions to its Evolved Expendable Launch Vehicle (EELV) line of rockets, a move that these officials say will drive up the unit cost of the Delta 2 and thus make the larger Atlas 5 more cost competitive.

Lockheed Martin Space Systems of Denver builds the Atlas 5, which along with Boeingโ€™s comparable Delta 4 rocket was developed under the EELV program. International Launch Services of McLean, Va., markets the Atlas 5 along with the Russian-built Proton rocket.

โ€œWe believe that as Delta 2 has become the sole NASA launch vehicle for medium-class missions, itโ€™s price has escalated so that the Atlas 5 401 is competitive,โ€ said a Lockheed Martin official, who did not want to be identified .

The Atlas 5 401 , the smallest vehicle in the Atlas family , can loft up to 12,500 kilograms to low Earth orbit and has been offered for NASA missions since June 2000 . But so far, NASA has ordered Atlas 5s for only two missions, the Mars Reconnaissance Orbiter, which launches this summer, and the Solar Dynamic Observatory.

The Delta 2 can launch a little more than 6,000 kilograms to low Earth orbit and for the past decade or so has been NASAโ€™s launch vehicle of choice for most competitively selected science missions.

Boeing Expendable Launch Systems of Huntington Beach, Calif., performed seven Delta 2 launches in both 2003 and 2004: six GPS missions and eight NASA launches. The most recent of those was the January launch of NASAโ€™s Deep Impact probe on its way to a scheduled July 4 meeting with a comet.

The Delta 2 has launched every GPS spacecraft since 1989 and has seven GPS missions remaining on its manifest through 2006. GPS launches aboard Atlas 5 and Delta 4 rockets are slated to begin in 2007.

The Lockheed Martin official said loss of the GPS missions will shift all costs associated with Delta 2 production and launch infrastructure to NASA. โ€œWe believe when you add all that up, that the Atlas 5 401 is a very competitive solution,โ€ the official said. โ€œWe will be amortizing the cost over government and commercial programs.โ€

The Lockheed Martin official further noted that the U.S. Space Transportation Policy, released in January, endorses EELV rockets for future U.S. government launch needs .

โ€œThe story the government has relayed to the industry is that the programs such as Titan, [older] Atlas and Delta 2, have a great heritage but are very expensive to operate,โ€ the official said.

Boeing spokesman Robert Villanueva said Delta 2 production will be adjusted to โ€ accommodate shifts in manifest,โ€ but declined to be more specific about the impact of losing the GPS missions .

Villanueva also pointed out that Delta 2 is sold on the commercial market, but the opportunities there are few and far between.

NASA still has 14 Delta 2 launches under contract โ€” although not all have been assigned to specific payloads โ€” that will take the program out through 2008 or 2009, said Karen Poniatowski, NASAโ€™s assistant administrator for launch services said in a January interview.

โ€œFor us, Delta 2 or a capability like it continues to be a requirement we have,โ€ Poniatowski said.

Lockheed Martin nonetheless believes there will be some opportunities to capture medium-class NASA launches before the agencyโ€™s current Delta 2 order expires.

โ€œWe are looking at opportunities between now and 2009 that overlap with NASAโ€™s current position that they will use the Delta 2,โ€ the Lockheed Martin official said. โ€œWe are anxious to pursue those missions. We have looked at both approved and potential programs and weโ€™ve identified some programs for which we are a good option.โ€

The official declined to be more specific.