United Launch Alliance has conducted its final launch of 2014, making use of a new upper stage engine on its Atlas V rocket to deliver a National Reconnaissance Office payload into orbit. Friday’s launch of NROL-35 dodged the weather and occurred at 19:19 local time (03:19 UTC on Saturday) from Space Launch Complex 3E at Vandenberg Air Force Base.
Atlas V Launch:
Although mission details are classified, the rocket was believed to be targeting a Molniya orbit – a highly elliptical trajectory with a period of 12 hours. The orbit is named after the Soviet Union’s Molniya communications satellites which were the first spacecraft to make use of the orbit.
The Atlas V flew in her 541 configuration, however her Centaur upper stage sported an RL10C engine for the first time.
As is normal for National Reconnaissance Office spacecraft, NROL-35’s mission has not been disclosed. The likely use of a Molniya orbit, however, suggests that it will either be used for communications or signals intelligence (SIGINT).
Currently the NRO has two types of spacecraft operating in these orbits; a series of communications satellites known as Quasar or the Satellite Data System (SDS) and a fleet of SIGINT birds known as Trumpet.
The Quasar satellites in Molniya orbit are ageing – the two most recent launches occurred in 2004 and 2007 with the third-youngest spacecraft having launched in 1998 – however it has been speculated that the NRO may be moving towards an all-geostationary Quasar constellation, with the last three satellites all going to geostationary orbit.
Recent geostationary Quasar launches have used Atlas V 401 and Delta IV Medium+(4,2) rockets, with the last Molniya orbit launch also using an Atlas 401, so it is unlikely that the satellites would have increased sufficiently in mass to require the far larger 541 configuration.
While the two most recent Trumpet satellites were launched using Atlas V 411 and Delta IV-M+(4,2) rockets, an increase in mass can be explained more easily since the last Trumpet launch occurred in 2008 and SIGINT satellites carry large antennae. It is therefore likely that NROL-35 represents the first in a new generation of satellites in the Trumpet series.
The NRO’s use of ELINT satellites in Molniya orbits began in the early 1970s, with the Jumpseat program. The exact number of Jumpseat spacecraft launched remains unclear as some of the spacecraft identified by contemporary observers as Jumpseat may have been early-generation SDS spacecraft and vice versa, however around seven of these satellites were launched by Titan III(33)B and III(34)B rockets between 1971 and 1983.
The first Jumpseat satellite, OPS 4788, was launched on 21 March 1971, with launches using the Titan III(33)B until its retirement in 1973, and subsequently the stretched 34B configuration.
In the mid 1990s, Jumpseat was replaced by a new series of three satellites which are known as Trumpet. All three spacecraft were launched from Cape Canaveral by Titan IV(401)A rockets; USA-103 on 3 May 1994, USA-112 on 10 July 1995 and USA-136 (NROL-4) on 8 November 1997.
The first launch of the program has been identified as one of the most-delayed launches of all time, spending almost three years on the launch pad – excluding two rollbacks to replace expired components – before it was finally able to fly. The mission patch listed even earlier dates, suggesting that the problems after reaching the launch pad were not the first of the satellite’s worries.
A new series of Molniya-orbit satellites began to launch in 2006, with two of the new type currently in orbit; USA-184 (NROL-22) was launched by a Delta IV-M+(4,2) on 28 June 2006, and USA-200 was launched by an Atlas V 411 on 13 March 2008.
The name of the new program is not known, and it is generally identified by observers as “Advanced Trumpet”, “Improved Trumpet” or “Trumpet Follow-On” since they appeared to be replacements for the Trumpet series. In addition to the SIGINT payloads, these spacecraft are equipped with NASA’s TWINS magnetospheric research instruments and SBIRS-HEO missile detection sensors.
While NROL-35 will not carry a TWINS payload, it is likely that it will play host to the third SBIRS-HEO instrument. SBIRS HEO-3 was reported to have been completed and shipped for integration with its host satellite in June 2013, so should be ready for launch around now.
SBIRS, the Space-Based Infrared System, is used by the US Air Force to provide early warning of missile launches. At present the constellation, which replaces the earlier Defense Support Program (DSP), consists of the two HEO payloads plus a pair of dedicated satellites in geostationary orbit. Two further geostationary satellites are scheduled for launch in late 2015 and 2016 and contracts to build two more were awarded in June.
At least one more SBIRS-HEO payload is under construction. The NROL-42 spacecraft, also scheduled to launch on an Atlas V 541 from Vandenberg, is likely the same type of spacecraft as NROL-35 and hence a good candidate to play host to this instrument.
NROL-35 was deployed by United Launch Alliance’s Atlas V rocket. First flown in 2002, the Atlas V was developed by Lockheed Martin as part of the US Air Force’s Evolved Expendable Launch Vehicle (EELV) program, in competition with Boeing’s Delta IV.
Friday’s launch marked its fifty-first flight, the third mission for the 541 configuration and the tenth Atlas V to launch from Vandenberg. The 541 configuration consists of a five-metre payload fairing, four solid rocket motors boosting the first stage and a single-engine Centaur upper stage.
The rocket, which had the tail number AV-051, departed Vandenberg from Space Launch Complex 3E, a pad which was originally constructed as part of the US Navy’s Point Arguello site.
The first launch from the complex occurred in July 1961, with an Atlas-Agena orbiting a MIDAS missile defence satellite.
The pad became part of Vandenberg Air Force Base in 1964 when the adjacent Air Force and Navy launch sites were amalgamated into a single facility. Atlas-Agena, Atlas-E/F and Atlas H rockets flew from the pad until the final Atlas H launch in May 1987, after which the complex fell into disuse.
During the mid-late 1990s SLC-3E was rebuilt for Lockheed’s Atlas IIAS rocket, which used the complex three times between 1999 and 2003 orbiting NASA’s Terra satellite and two pairs of NOSS ocean surveillance satellites for the NRO.
The first Atlas V launch from the pad did not occur until March 2008 as originally Lockheed had not planned to offer the Atlas from Vandenberg. This changed when Atlas was awarded several launch contracts that had originally been assigned to the Delta IV after it was found that Boeing had illegally obtained confidential information from Lockheed during the bidding process for the EELV program.
The first Atlas V launch from Vandenberg carried the last of the NRO’s previous-generation Molniya orbit SIGINT spacecraft, USA-200 or NROL-28, on 13 March 2008.
The flight profile for Friday’s launch wasn’t announced, however like any Atlas V mission it began with ignition of the RD-180 engine powering the first stage around 2.7 seconds before launch. Ignition of the four Aerojet solid rocket motors attached to the first stage and liftoff occurred at around T+1.1 seconds.
The solids burned for about 95 seconds, remaining attached for a little longer after burnout to avoid dropping debris in restricted areas where they may pose a danger to shipping or oil drilling. Fairing separation occurred midway through first stage flight.
The mission coverage ended at that point, due to the nature of the mission. However, first stage flight ended with Booster Engine Cutoff (BECO), a little over four minutes after liftoff, with the RD-180 shutting down. First stage separation occurred six seconds later, with second stage ignition about ten seconds after that.
The second stage of the Atlas V is a Centaur, which can be powered by one or two RL10 engines depending upon mission requirements – to date every Atlas V launch has used the single-engine version.
While Atlas V launches to date have used an RL10A-4-2 engine to power the Centaur, Friday’s mission introduced the new RL10C-1. The RL10C-1 and RL10C-2 are intended to replace the Atlas’ RL10A and Delta IV’s RL10B-2 engines respectively with a single common design.
Derived from the RL10B series, which was spun off in the 1990s for Delta upper stages beginning with the short-lived Delta III, the RL10C also incorporates more modern production processes to reduce the cost of assembly and provide greater standardisation across ULA’s fleet.
Trumpet satellites are inserted directly into Molniya orbits, unlike Quasar satellites which are deployed into lower orbits and then manoeuvre to their operational orbits under their own power. Because of this, Centaur is expected to perform two burns; one to achieve a low Earth parking orbit, and a second to reach the final deployment orbit.
Amateur satellite watchers, via the Seesat-L mailing list, are predicting that NROL-35 will separate into an orbit of around 1,120 by 37,600 kilometres (696 by 23,400 miles, 604 by 20,300 nautical miles), with an inclination of 63.56 degrees. Shortly after launch the spacecraft will likely manoeuvre to its operational orbit.
Friday’s mission marked the eighty-third orbital launch attempt of 2014 and the twenty third to be conducted by the United States – fourteen of which were made by United Launch Alliance.
The Atlas V made its fiftieth launch earlier in the year and with this latest launch making it nine launches in a year for the first time. This is the highest flight rate Atlas has achieved since 1995, and the first time in thirty years that three Atlas rockets have launched from Vandenberg in the same year.
ULA began the year with its successful deployment of the TDRS-12 communications satellite for NASA on 24 January atop an Atlas V. The first Delta launch of the year occurred on 21 February with a Delta IV Medium+(4,2) carrying a GPS satellite into orbit.
In April two Atlas launches a week apart orbited a DMSP weather satellite, USA-249, from Vandenberg followed by the NROL-67 (USA-250) satellite for the NRO from the Cape. USA-250 is believed to be a geosynchronous SIGINT satellite, possibly a follow-up to the Mercury satellites of the 1990s.
In May, the Delta IV made its second launch of the year carrying another GPS satellite, while an Atlas launch five days later deployed NROL-33, a Quasar communications satellite. July saw the return of the Delta II, with ULA launching NASA’s Orbiting Carbon Observatory 2 (OCO-2) mission – a reflight of a satellite which had been lost in a 2009 Taurus launch failure – from Vandenberg.
A Delta IV launch from Cape Canaveral at the end of the month conducted the AFSPC-4 mission, deploying a pair of Geosynchronous Space Situational Awareness Program (GSSAP) satellites and the Automated Navigation and Guidance Experiment for Local Space (ANGELS) technology demonstration mission.
The third GPS launch of the year was conducted in early August, this time using an Atlas V to deliver the satellite into medium Earth orbit. Towards the middle of the month the year’s second Atlas V launch from Vandenberg occurred, carrying the commercial WorldView-3 imaging satellite.
Further Atlas launches in September and October deployed the CLIO communications satellite for an undisclosed US government agency and a fourth GPS spacecraft.
The final Delta IV launch of the year occurred on 5 December, with a Delta IV Heavy successfully carrying NASA’s Orion spacecraft on its maiden flight, Exploration Flight Test 1 (EFT-1).
ULA will begin 2015 with the launch of the third MUOS communications satellite for the US Navy, which is currently scheduled to depart Cape Canaveral on 21 January. A little over a week later the first Delta launch of the year will see a Delta II fly from Vandenberg with NASA’s SMAP spacecraft.
The first Delta IV mission of the year is scheduled for late March with a GPS satellite. A provisional launch schedule for 2015 shows nine or ten Atlas V missions, three or four Delta IVs and a single Delta II launch.
Missions slated to be launched by the Atlas V next year include NASA’s Magnetospheric Multiscale (MMS) mission, the commercial Morelos 3 communications satellite and a Cygnus resupply mission to the International Space Station for Orbital Sciences Corporation.
The last US launch of 2014 is currently scheduled to be conducted next week, with SpaceX launching a Falcon 9 with a Dragon spacecraft atop on a resupply mission to the International Space Station. The final launch of the year will most likely be conducted by Russia in the last week of December.
(Images via ULA)