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Expecting Twins: A How-To Guide to Dual Launch

June 26, 2013  - By
Credit: OHB

Recently released views of the next two Galileo satellites in the European Space Agency’s testing lab, along with dual-launch rumblings from the U.S. Air Force and Lockheed Martin, occasion this story about two birds with one drone. That is, an unmanned autonomous vehicle bound for the exosphere. The rest of the GNSS world is on board with this topic; isn’t it about time GPS caught up?

The first two Galileo Full Operational Capability (FOC) satellites will launch as a pair, earlier advertised as a September blast, now possibly delayed until December; a second dynamic duo will follow sometime thereafter. Then two again, and two, and two, until the Ariane 5 rocket launches four at once. Four!

The latest official U.S. Air Force plans say that by the ninth GPS III satellite (SV-09), the program plans to initiate programmatic and hardware changes to allow for the first-ever GPS dual launch. The motive, of course, is cost savings. The GPS program (probably) has no need to hurry, as other GNSSes do, in order to have a full constellation operative broadcasting — previous predictions about constellation gaps notwithstanding.

Even with dual launch, according to Lockheed Martin Navigation Systems vice president Keoki Jackson (and here I am drawing from Don Jewell’s Space Symposium column), from SV-09 forward the savings will only amount to about $70 million per launch, because it will require a larger launch vehicle.

Only $70 million. Well, to quote Senator Everett Dirksen, adjusting for inflation, “$70 million here, $70 million there, pretty soon, you’re talking real money.”

Take this all in the context of GPS III having reached the point that it will cost nearly $450 million to place a single GPS space vehicle and payload in orbit.

Rising costs and the possibility to combat them with dual launches constitute at least one of the driving forces behind the NavSat or NibbleSat drawing-board concept: a small GPS satellite, without the burden of other non-nav payloads.

Coincidentally, an initiative underway seeks to evaluate “new launch entrants,” according to General Willie Shelton, commander, Air Force Space Command. “If a new entrant can come in and provide a cost-effective launch capability for several launches, then we will look seriously at them as well,” he told Don Jewell in an interview nearly a year ago.

Jewell: “Why don’t we move into the arena of trying to pin down a vehicle or set of vehicles for dual launch? You and I once discussed GPS III vehicles 7-8 for that honor, and you mentioned at the time that it was a moving target. Where do we stand today?

General Shelton: Don, I think we are now probably talking about GPS III vehicles 9-10.  We are still in the  study phase on this issue with Lockheed Martin and United Launch Alliance. We are still trying to figure out how we would do dual launch and what kind of capabilities we need to develop. I think this is really the wave of the future…being able to put two up simultaneously will save us a lot in launch costs.”

In April of this year, John Frye, Lockheed Martin’s GPS III capability and affordability insertion manager, reiterated, in comments regarding the Delta Preliminary Design Review (dPDR) for the GPS III satellite, “The design modifications from this dPDR address ways to further reduce Air Force launch costs by $50 million per satellite through dual launch of two GPS III space vehicles on a single booster. This successful dPDR milestone sets the stage to proceed with SV09 design maturation.”

Rockets. Recently,  the U.S. Air Force Space and Missile Systems Center (SMC) signed a Cooperative Research and Development Agreement (CRADA) with Space Exploration Technologies Corp., better known as SpaceX, as part of the company’s effort to certify its Falcon 9 v1.1 launch system for National Security Space (NSS) missions.

SMC and SpaceX will look at the Falcon’s flight history, vehicle design, reliability, safety systems, and other aspects. Once the evaluation is complete, the SMC commander will determine whether SpaceX has the capability to successfully launch NSS missions using the Falcon 9 v1.1.

Currently, United Launch Alliance’s Delta IV and Atlas V are the only certified launch vehicles capable of lifting NSS payloads — such as the GPS satellites — into orbit.

The Falcon CRADA may be a preliminary, tentative move towards dual-launch capability.  Consider:

An earlier iteration, Falcon 9, can reportedly lift payloads of 4,850 kilograms (10,700 lb) to geostationary transfer orbit (GTO). The Falcon 9 v1.1— subject of the CRADA and scheduled for first flight in mid-2013—will use a longer first stage powered by nine Merlin 1D engines arranged in an octagonal pattern. Development testing of the v1.1 Falcon 9 first stage was just completed in June. These improvements will increase the payload capability by nearly 50 percent. The new first stage can also be used as side boosters on Falcon Heavy, which reportedly will have a capability of lifting 12,000 kg (26,000 lb) to GTO.

According to an Air Force fact sheet, the GPS III satellite has a launch weight of 8,115 lb.

The Atlas V 401 rocket, most recently used to launch the GPS IIF-4 satellite in May, has a GTO launch capability of 4,750 kg. (10,472 lb.)  A steroid version of the Delta IV, the Delta IV Heavy, has a GTO launch capability of 13,130 kg (28,950 lb), more than any other currently available launch vehicle. It also carries a more substantial price tag.

To sum up these various vectors pointing largely in the same direction, GPS has a potential in the somewhat near-mid distant future of going to dual launch.

Meanwhile, this has been fait accompli for the other GNSSes.


The first two in-orbit validation (IOV) satellites built by Astrium traveled aloft together in October 2011, as did the third and fourth IOV satellites in October 2012.

According Paul Flament, European Commission Programme Manager and Head of the EU Satellite Navigation Programme Unit, in an interview earlier this year with GPS World, “Satellites 5 and 6 will be launched in September of this year, aboard a Soyuz launcher from Kourou, and numbers 7 and 8 will follow in December.” These launches may since have been re-adjusted to later dates, respectively.

“Then, in 2013 we will see three Soyuz launches of two satellites each. We do not have the precise launch dates yet, but they are likely to be in April, June, and September. In December 2014, we expect to have the first launch using the Ariane 5 launcher, which is capable of deploying four satellites in one go. This means that by the end of 2014 Galileo will have deployed 18 satellites in orbit.

“In 2015, there will be two Ariane 5 launches, one in the middle of the year, one at the end, each carrying four satellites.”


Within days, perhaps, three GLONASS-M satellites will blast off together from Baikonur: GLONASS 48, 49, 50. This is only the latest of GLONASS triple launches.

As Richard Langley is my witness, the Russians accomplished a GLONASS hat-trick as long ago as September 1986!  The first in a more recent series of triplets, in December 2010, failed rather spectacularly and cost Russia an estimate 5 billion roubles ($160 million), setting back GLONASS by six months. The system has since intermingled single- and triple-satellite launches.


China has demonstrated success with two dual launches of mid-Earth orbit satellites, among its constellation lodged at varied heights. Compass-M3 and Compass-M4 rose together in April 2012, as did M5 and M6 in September of that year.


About the Author:

Alan Cameron is the former editor-at-large of GPS World magazine.

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