United Launch Alliance launched an Atlas V rocket Tuesday evening, carrying into orbit a classified payload called CLIO for an undisclosed agency of the United States government. The launch occurred at the end of the launch window at 20:10 (00:10 UTC), following weather-related issues at Cape Canaveral in Florida.



Atlas V launch:

The payload for Tuesday’s mission is a spacecraft named CLIO. Constructed by Lockheed Martin, CLIO is believed to be based on the A2100 bus that Lockheed produces for commercial communications satellites. In this regard CLIO is similar to a previous clandestine spacecraft, PAN, which was launched by an Atlas V in similar circumstances five years ago.

Also built by Lockheed, around the A2100 platform, PAN was deployed by an Atlas V under a commercial delivery-in-orbit contract for a US Government agency which has never been identified.

From the Lockheed Martin logo which is prominent on its mission patch, it is possible that the CLIO mission may be using a similar contract to PAN. It is unclear whether the PAN and CLIO missions are related beyond these similarities.

Following its launch in September 2009 the satellite was placed into geostationary orbit, and has been moved frequently between orbital slots since entering service. It is currently orbiting over the equator at a longitude of 47.5 degrees, off the East coast of Africa. Based on the typical lifespan of an A2100 satellite, PAN is likely to be a little over a third of the way through its operational life.

Communications is one possible application for the CLIO satellite. If it is placed into a geosynchronous orbit the satellite could potentially be used for a similar mission to PAN. The United States already operates several fleets of geosynchronous communications satellites; AEHF, MUOS, SDS and WGS.

The Advanced Extremely High Frequency spacecraft, and the MILSTAR satellites which preceded them, are large and powerful satellites intended to provide the backbone of the United States’ strategic communications while Wideband Global Satcom (WGS) and its predecessor the Defense Satellite Communications System (DSCS), are geared towards communications with mobile and deployed units, including on the battlefield.

The Mobile User Objective System (MUOS) is a US Navy program, which is in the process of replacing the older UHF Follow-On (UFO) spacecraft. It is used primarily for communication with naval assets, including ships, submarines and aircraft. The Satellite Data System (SDS) is used by the National Reconnaissance Office to relay data from its reconnaissance satellites to the ground.

Another potential application is to monitor other satellites, either visually or in terms of the signals they transmit and receive.

The Prowler satellite, deployed from Space Shuttle Atlantis during the STS-38 mission of 1990, is believed to have been used to conduct signals intelligence monitoring of other spacecraft from its near-geosynchronous orbit.

Designed for low observability, Prowler’s existence was only confirmed in 2011 after a census of near-geosynchronous objects turned up one more satellite than had been expected. Information leaked in 2004 had hinted at its existence and purpose.

Two other missions have been conducted to monitor geosynchronous satellites; DARPA’s MiTEx satellites, launched in 2006, were used for a technology demonstration project of this nature, while the GSSAP satellites launched by a Delta IV earlier this year, as part of the AFSPC-4 mission, form part of an operational geostationary monitoring constellation.

The patch for Tuesday’s launch gave little away, consisting of little more than the payload name and Lockheed Martin’s insignia. A second patch, likely produced by the launch team, features several symbols.

At the left of the patch is the Roman numeral II, suggesting that it may be the second satellite in a series or that two satellites are being launched. The symbol at the top of the patch appears to be the infinity sign, while the one on the right of the patch may be an algebraic X or a mirrored letter C.

Symmetry seems to be an important theme as all three symbols are symmetrical along both the horizontal and vertical axes. This is also evident in the presentation of the flight number, with the A and V of AV-049 reflected along the centre of the patch.

The five stars at the bottom are part of the insignia for the Fifth Space Launch Squadron, responsible for overseeing the launch.

The Atlas V used for Tuesday’s launch, AV-049, was the forty ninth Atlas V to fly.

Making use of the 401 configuration, with no solid rocket motors, a single engine Centaur upper stage and a four meter payload fairing, the flight departed from Space Launch Complex 41 of the Cape Canaveral Air Force Station.

The current SLC-41 was constructed between 1999 and 2002, on the site of a former Titan pad. Originally built for the Titan III in the mid-1960s, Complex 41 hosted its first launch in December 1965 with the third Titan IIIC mission which orbited four satellites.

Twenty seven Titan rockets, in the IIIC, IIIE, IVA and IVB configurations, were launched from LC-41 between 1965 and 1999, including the vehicles which carried NASA’s Helios, Viking and Voyager missions to study the Sun, explore Mars and visit the outer planets.

The final Titan launch from the complex, which carried a Defense Support Program (DSP) missile detection satellite, ended in failure after an upper stage malfunction. The previous launch had also failed, during first stage flight, after an electrical fault knocked out the rocket’s guidance system.

Work to demolish the Titan facilities at SLC-41 began in late 1999, with a clean-pad approach being adopted for the Atlas V. The rocket is stacked vertically atop a mobile launch platform, off-pad in the nearby Vertical Integration Facility. Shortly ahead of launch the platform is transported to the launch pad with the rocket atop it – rollout for the CLIO mission occurred on Monday.

The Atlas V is a two stage rocket which was developed by Lockheed Martin as part of the US Air Force’s Evolved Expendable Launch Vehicle (EELV) program, along with Boeing’s Delta IV. Both of these rockets are now built and operated by United Launch Alliance following the December 2006 merger of Boeing and Lockheed’s launch divisions.

The Atlas V made its first flight in 2002, carrying a Hot Bird communications satellite for commercial operator Eutelsat, and in its forty-eight launches to date it has achieved a near-perfect success record. The only blemish on this record came during the June 2007 launch of NROL-30, or USA-194, a pair of Intruder signals intelligence satellites for the National Reconnaissance Office.

On that mission a faulty valve allowed propellant to leak from the upper stage during a coast phase, and when the stage was restarted it was unable to fire for the full planned duration of the burn. Despite this underperformance the NRO was able to recover its satellites and place them into the correct orbit under their own power.

The Atlas’ first stage is a Common Core Booster, which is powered by an RD-180 engine burning RP-1 and liquid oxygen. This engine ignited 2.7 seconds before the countdown reached zero, with liftoff occurring approximately 1.1 seconds after the zero point in the count, when the thrust produced by the first stage engine exceeded the weight of the vehicle.

Climbing away from its launch pad, AV-049 headed on a south-easterly launch azimuth with a series of pitch and yaw adjustments that began seventeen and a half seconds into flight. The rocket’s speed reached Mach 1 around the one minute, 19.1-second mark in the mission, with the vehicle passing through the area of maximum dynamic pressure (max-Q) 11.8 seconds later.

The first stage burned for four minutes and 1.8 seconds before the RD-180 shut down, an event designated Booster Engine Cutoff (BECO). BECO was followed six seconds later by the separation of the spent first stage from the vehicle. With the spent stage separated the second stage began its prestart sequence, with ignition taking place ten seconds after staging.

The second stage of AV-049 is a single-engine Centaur. Powered by an RL10A-4-2 engine, the Centaur made two burns for Tuesday’s launch. The first of these lasted for 13 minutes and 40.3 seconds, taking AV-049 and her payload into an initial parking orbit.

Separation of the payload fairing from around CLIO occurred around eight seconds into the burn.

After the end of the first burn, the Centaur entered a two and a half hour coast phase. At two hours, forty seven minutes and 52.9 seconds mission elapsed time the Centaur’s engine restarted for the second burn.

This burn lasted 70.4 seconds, injecting CLIO into its planned deployment orbit. Parameters for this orbit have not been published, however observers have noted that the burn times would place the satellite in a lower orbit than would be expected for a geosynchronous launch.

This has led to speculation that the satellite may not be bound for a geosynchronous mission, but instead for a near-equatorial medium Earth orbit. It should be noted, however, that the mission profile for the CLIO launch is similar to that which was used for PAN, albeit with a longer first burn and coast phase, and a shorter second burn.

The ground tracks for the CLIO launch show the rocket’s trajectory will be somewhat more southerly than is usual for a geosynchronous launch, suggesting that if the satellite is bound for the geosynchronous belt it will probably be operated in an inclined orbit rather than the more typical zero-inclination geostationary orbit over the equator.

One possibility is that CLIO is a replacement for AMC-14, a commercial communications satellite which was purchased by the US Department of Defense in 2008 after a launch failure left it unusable for its original mission.

Although AMC-14 was designed for a fifteen year lifespan, it is likely that recovering it from the orbit its Proton carrier rocket left it in expended a significant portion of its fuel reserves, reducing its life expectancy.

If CLIO is not a geosynchronous satellite, it not immediately clear what purpose placing it into a low-inclination Medium Earth orbit would serve, as such a position would be of little or no value for most of the typical military applications of satellites. The purpose of CLIO is something which is likely to become more clear once the spacecraft is established in orbit and can be observed by amateur satellite watchers.

Tuesday’s launch was the fifty sixth of the year globally, the eighteenth for the United States and the eleventh for ULA. It was the seventh Atlas launch of 2014, with two more planned. The next Atlas mission is scheduled for the end of October, carrying a GPS satellite in another mission from Cape Canaveral.

Atlas will then close its year with the deployment of the NROL-35 payload from Vandenberg – a mission which will mark the debut of a re-engined Centaur powered by the new RL10C powerplant.

In addition to these Atlas missions, ULA has one more Delta IV to launch this year. Carrying NASA’s Orion spacecraft on the Exploration Flight Test 1 (EFT-1) mission, this will make use of the Delta IV Heavy configuration. This is currently slated for early December, lifting off from Space Launch Complex 37B at Cape Canaveral.

(Images, via ULA and NASA)