A new Delta IV configuration has made its first flight Tuesday, carrying the NROL-25 payload for the United States National Reconnaissance Office. Liftoff from Space Launch Complex 6 at the Vandenberg Air Force Base in California was on schedule at 23:12 UTC (16:12 local time).
Delta IV Launch:
Whilst its mission is officially classified, NROL-25 is believed to be the second in a series of new radar imaging satellites, developed as part of the NRO’s Future Imagery Architecture programme. The first such satellite, USA-215, was launched in September 2010 by an Atlas V rocket, and is believed to be operational. The FIA Radar, or FIA-R, satellites are replacements for the Lacrosse or Onyx satellites launched between 1988 and 2005.
The NRO first experimented with radar imaging in the 1960s, with the Quill programme. Only one prototype satellite was launched, OPS 3762, which was placed into orbit by a Thrust-Augmented Thor SLV-2A with an Agena-D upper stage in December 1964. The spacecraft operated for four days, imaging parts of the United States to avoid provoking the Soviet Union, and returning the images at the end of its mission using a KH-4 film capsule. The programme was abandoned because technology did not exist at the time to produce images of high enough resolution to be useful.
By the 1980s, technology had advanced sufficiently for radar imaging to be useful, and on 2 December 1988, the Space Shuttle Atlantis lifted off from LC-39B at the Kennedy Space Center on mission STS-27, carrying the first in a new series of radar imaging satellites. Named USA-34, the satellite was deployed into a low Earth orbit at an inclination of 57 degrees.
It has been rumoured that an antennae on the spacecraft failed to deploy, necessitating an unscheduled EVA during the deployment mission to repair it, however given the short duration of the mission, it is unclear whether there would have been time to accomplish this.
USA-34 is believed to have originally been slated for launch aboard Space Shuttle Discovery on STS-62B, the second planned Shuttle launch from Vandenberg, in September 1986.
This mission was cancelled, along with all other Shuttle missions from Vandenberg, following the loss of Challenger on STS-51L. After operating, apparently successfully, for over eight years, USA-34 was deorbited around 25 March 1997.
The Lacrosse satellites were produced by Martin Marietta, and later Lockheed Martin, and carry Synthetic Aperture Radar systems, relaying images to earth via the NRO’s Satellite Data System communications satellites. Lacrosse grew out of the Project Indigo design study in the late 1970s, with development beginning in 1983. Some of the later spacecraft have also been identified as Onyx, and it is unclear whether this name refers to a second-generation spacecraft, or whether the programme was renamed once its original name became public as the NRO did with the Aquacade satellites (originally named Rhyolite) in 1975.
USA-34 was the only Lacrosse satellite to be deployed by the Space Shuttle; the next four were all launched by Titan IV rockets. The second spacecraft, USA-69, was launched by a Titan IV(403)A on 8 March 1991. The launch was the first flight of a Titan IV from Vandenberg, and placed the satellite into an orbit inclined at 68 degrees, establishing the second of two orbital planes within the system. USA-69 remained in service for over twenty years, finally being deorbited on 26 March 2011.
The remaining Lacrosse satellites are still in orbit, and believed to be operational. The third, USA-133, was launched on 24 October 1997 to replace USA-34. Like USA-69, it was launched from Vandenberg by a Titan IV(403)A, however it was placed into the less-inclined orbital plane. The launch is believed to have been designated NROL-3 under the numbering system introduced in 1996, however this has not been confirmed, and marked the last Titan IVA launch from Vandenberg.
USA-152, or NROL-11, was launched by a Titan IV(403)B on 17 August 2000, into the higher inclination plane. It was followed by USA-182, or NROL-16, which was launched into the low inclination plane on 30 April 2005. USA-182 was the only Titan-launched Lacrosse not to be launched from Vandenberg; it was moved to Cape Canaveral in order to relieve pressure on Vandenberg’s Titan manifest; its launch becoming the final flight of a Titan rocket from Cape Canaveral, and the penultimate Titan launch overall. The change of launch site has also caused confusion over the configuration which the rocket flew in; the 403 configuration was one of two variants optimised to launch from Vandenberg, whilst launches from Cape Canaveral which did not require an upper stage used the 405 configuration. It is therefore unclear whether USA-182 was launched by a Titan IV(403)B, or a Titan IV(405)B.
With FIA satellites now being launched to replace them, it is unlikely that new Lacrosse satellites will be launched, however it is not impossible. The identity of the NROL-15 payload, slated for launch on a Delta IV Heavy from Cape Canaveral in June, has not yet been confirmed, and the payload is believed to require additional performance compared to previous Delta IV missions. It is possible, but unlikely, that it could be a Lacrosse satellite. The failed USA-193, or NROL-21, satellite may also have been a prototype radar imaging satellite.
The FIA programme was originally intended to replace not just the Lacrosse satellites, but also the KH-11 electro-optical imaging satellites. The optical part of the programme was abandoned in 2005 as it was severely overbudget and behind schedule. Bruce Carlson, the director of the NRO, described one of its programmes as being around “700 percent over in schedule and 300 percent over in budget [sic]”; he is believed to have been referring to FIA. NROL-25 was originally expected to launch in 2007.
The original mission patch for NROL-25 featured the name Altair, with depictions of an eagle and a compass, leading to initial speculation that the mission might carry a pair of NOSS naval signals intelligence satellites. This patch appears to have been replaced by one featuring the words “Victoria Commissa Omnibus”, meaning “Committed to victory for all”. There does not appear to be a mission name.
The Delta IV which will be used for the NROL-25 mission is Delta 359, although for the second consecutive launch this number has not been painted on the rocket. According to one of the patches released for the mission, the rocket has been named Electra. The first Delta IV to fly in the Medium+(5,2) configuration, Electra consists of a single Common Booster Core first stage augmented by two GEM-60 solid rocket motors, with a five metre Delta Cryogenic Second Stage (DCSS). The (5,2) is the last of the currently planned Delta IV configurations to make its maiden flight.
The Delta IV family consists of five configurations. The Medium configuration is the smallest, consisting of a single CBC topped with a four metre DCSS. Three have been launched to date; the first in March 2003 with USA-167, a DSCS communications satellite. The second was launched in August of the same year with USA-170, the final DSCS satellite. Both of these launches employed Integrated Apogee Boost System (IABS) third stages, however these were considered part of the payload not the carrier rocket. The third Medium launch occurred in November 2006, with USA-191, a DMSP weather satellite.
The Delta IV Medium+ configurations feature a reinforced CBC, augmented by GEM-60 solid rocket motors. There are three configurations; the (4,2), (5,2) and (5,4). The first digit of the configuration number denotes the diameter of the upper stage, and the second denotes the number of boosters. The (4,2) is the most-flown Delta IV configuration, with eight launches, and was also the configuration used for the Delta IV’s maiden flight on 20 November 2002 with the Eutelsat W5 satellite.
Its next flight was the May 2006 launch of GOES 13, and the following month another (4,2) conducted the first Delta IV launch from Vandenberg Air Force Base, carrying the USA-184 (NROL-22) satellite; an “Improved Trumpet” ELINT spacecraft. The fourth (4,2) launch carried GOES 14 into orbit in June 2009, with the fifth orbiting GOES 15 in March 2010. In May 2010, the sixth (4,2) launched USA-213, a GPS satellite. The seventh was launched in March 2011 with USA-227, or NROL-27, an SDS communications satellite, and its most recent launch came in July 2011, with USA-232, another GPS spacecraft.
The Medium+(5,4) configuration has launched twice, both flights carrying Wideband Global Satcom communications satellites. Its first launch occurred in December 2009 with USA-211, and it’s second in January 2012 with USA-233.
The final Delta IV configuration is the Delta IV Heavy, the most powerful rocket currently in service. Consisting of three Common Core Boosters burning in parallel, with a five metre DCSS upper stage, the Heavy has flown five times. Its first launch, in December 2004, carried a demonstration satellite and two 3CS nanosatellites. Due to a problem with cavitation in the fuel lines, all three CBCs shut down early, leaving the spacecraft were placed into lower-than-planned orbits, and resulting in the failure of the 3CS missions. This remains the only Delta IV launch failure to date.
The second Heavy launched in November 2007, with the final Defense Support Program missile detection spacecraft, USA-197. Despite a successful launch, the satellite failed after only a few months in orbit. The third Delta IV Heavy carried a Mentor satellite for the NRO, designated USA-202, or NROL-26, and was launched in January 2009. The next launch, in November 2010, also deployed a Mentor satellite; USA-223 or NROL-32. Then, in January 2011, the fifth Delta IV Heavy, and the first to fly from Vandenberg, deployed USA-224 or NROL-49, a KH-11 optical imaging satellite. The Delta IV Medium and Heavy configurations are the only fully-cryogenic orbital launch systems currently in service.
The mission profile for NROL-25 is classified, however early flight events will follow a fairly typical pattern. With the countdown at T-5.5 seconds, the first stage’s RS-68 engine ignited, followed by the solid rocket motors at T-0, at which time Electra began her ascent to orbit. About 50 seconds into flight, the vehicle attained supersonic speed, and twelve seconds later it passed through the area of maximum dynamic pressure.
The solid rocket motors burned for 100 seconds, before separating and falling into the Pacific Ocean. Main Engine Cutoff, or MECO, occured about 246 seconds into the flight, with the CBC being jettisoned six seconds later. The nozzle of the RL10 engine then extended, with ignition occurring thirteen seconds after staging.
The launch was delayed several days after the extendable part of the nozzle was found to have been out of position. Events after the ignition of the RL10 will be unique to mission requirements, however a typical mission would consist of two burns, the first lasting around twelve and a half minutes and the second, around an hour later, lasting about 14 seconds. It is unclear whether fairing separation will occur late in the first stage flight, or early in second stage flight.
Electra launched from Vandenberg Air Force Base’s Space Launch Complex 6 (SLC-6). Constructed as a Titan III launch complex for the Manned Orbiting Laboratory programme in the 1960s, SLC-6 never supported a Titan launch due to the cancellation of MOL. It was subsequently converted for Space Shuttle launches, however safety concerns after the loss of Challenger resulted in plans to launch the Shuttle from Vandenberg being abandoned.
Again, SLC-6 remained unused, resulting in an urban legend that the pad was cursed because it was built on a Native American burial ground; however no evidence has been found to support this.
The first launch from SLC-6 finally occurred in August 1995, when the first Lockheed Launch Vehicle (later Athena I) flew from the pad. Four Athenas were launched from the pad, however when the Athena was withdrawn in 2001 the pad was again inactive. SLC-6 was later rebuilt for the Delta IV Medium configurations, with modifications occurring between 2007 and 2010 to accommodate the Delta IV Heavy as well. NROL-25 will be the fourth Delta IV launch from the pad; following tow launches in 2006, and one in 2011.
Tuesday’s launch was the second Delta IV launch of the year, following the launch of USA-233, or WGS-4, in January. The next launch is scheduled for June, from Cape Canaveral, with a Delta IV Heavy performing the NROL-15 mission. The next Delta launch from Vandenberg is likely to be of NROL-65, probably a KH-11 satellite, next year.
(Images via ULA, NROL, Global Security and L2 Historical)