The United Launch Alliance (ULA) have launched an Atlas V, tasked with deploying a payload for the National Reconnaissance Office. The mission, designated NRO Launch 67 (NROL-67), lifted off from Cape Canaveral’s Space Launch Complex -41 (SLC-41) on schedule at 13:45 local time (17:45 UTC) on Thursday.
Atlas V/NROL-67 Mission:
The mission of the NROL-67 payload is classified. While this has never stopped observers identifying most NRO spacecraft ahead of their launch, this marks the first use by the NRO of an Atlas V 541 rocket, indicating that it is likely a new class of payload. As such, the spacecraft is much harder to identify as there are no similar launches to compare it to.
Notices to airmen (NOTAMS) and hazard areas published ahead of the launch show that the rocket will launch to the East, over the Atlantic Ocean, to a low-inclination orbit. Such a trajectory means that the payload is almost certainly bound for a geosynchronous orbit, since other equatorial regimes are of little value for reconnaissance.
The NRO has had two or three principal constellations of spacecraft in geosynchronous orbit, each fulfilling different purposes. The Quasar or Satellite Data System (SDS) spacecraft are used to provide communications between lower-orbit reconnaissance satellites and ground stations. Three generations of SDS satellites have been launched since 1976.
The first-generation SDS constellation consisted solely of satellites in Molniya orbits; inclined elliptical trajectories which keep the satellites over high latitudes for long periods of time.
The second generation introduced a geostationary component – USA-67 was launched aboard Space Shuttle Atlantis during the STS-38 mission, along with Prowler; a one-off mission whose existence has never been officially acknowledged.
More geosynchronous satellites were introduced in the third-generation system; two spacecraft were launched to geostationary orbit at the beginning of the 2000s, with replacements launching in 2011 and 2012.
Quasar launches during the EELV era have made use of Atlas V 401 and Delta IV Medium+(4,2) rockets.
The use of the more powerful Atlas V 541 for NROL-67 means that this payload is unlikely to be related to the Satellite Data System; however it is still possible that it could be a newer and larger satellite, two spacecraft launching together, or a satellite being placed directly into geostationary orbit rather than the transfer orbit usually used for such missions.
The remainder of the NRO’s geostationary fleet is used for signals intelligence (SIGINT) of one form or another. Orion satellites, formerly known as Magnum, are believed to be used to intercept and eavesdrop upon communications while the Mercury series pinpoints radar signals, although some reports reverse the assumed missions of these two series.
Another suggestion has been that the Mercury series is used to collect data from communications while Orion intercepts telemetry data from foreign missiles.
A follow-on to the Rhyolite or Aquacade missions of the 1970s, Orion satellites are among the largest in geostationary orbit and have historically required the largest rockets available to reach orbit. The first two satellites were deployed from Space Shuttle Discovery, during the STS-51C and STS-33 missions of 1985 and 1989 respectively.
Deployment from the Shuttle made use of an Inertial Upper Stage to place the spacecraft into their final geosynchronous orbit.
The third Orion spacecraft, an enlarged variant which observers have dubbed “Advanced Orion” and has been known apocryphally as Mentor, was deployed by a Titan IV(401)A in May 1995. Titan IV(401)B launches followed in 1998 and 2003, the latter marking the final Titan-Centaur launch. With the Titan IV gone, replenishment launches in 2009, 2010 and 2012 made use of Delta IV Heavy rockets.
The most recent mission, June 2012’s NROL-15, featured modifications to the Delta IV – already the most powerful rocket in America’s launch fleet – to increase its payload capacity.
These were rumoured to be required due to the mass of the satellite. In light of this NROL-67 seems too small to be a part of this series, unless new technologies have enabled significant mass reductions over the earlier vehicles.
The Orion fleet is also at full strength, with three recently-launched satellites, so it would be a strange time for a replacement to enter service.
The status of the Mercury fleet, which has not been replenished in over fifteen years, is unclear. These satellites form part of a series which began with seven Canyon satellites launched by Atlas SLV-3A Agena-D rockets between 1968 and 1977.
One of these spacecraft failed to achieve orbit, with the remaining six operating in elliptical geosynchronous orbits, with apogees above and perigees below geostationary altitude.
The Chalet series, which was renamed Vortex after its original name was leaked, replaced Canyon. Six were deployed between 1978 and 1989; the first three using Titan III(23)C rockets and the last three using Titan III(34)D/Transtage vehicles.
Between 1994 and 1998 three Mercury satellites were launched by Titan IV(401)A, with the two which survived launch entering geostationary orbit rather than the more eccentric orbits used by their predecessors.
The last Mercury launch, which also marked the final flight of the Titan IVA, took place on 12 August 1998. Forty five seconds after liftoff, the rocket was destroyed by range safety after going off course and beginning to disintegrate.
The failure was blamed on frayed wiring causing a short-circuit which interrupted the supply of power to the vehicle’s guidance system.
It was the first of two back-to-back launch failures from Cape Canaveral – along with the Delta III’s maiden flight a fortnight later – and the first of three consecutive failures for the Titan IV.
Mercury was to have been replaced as part of the Integrated Overhead SIGINT Architecture (IOSA) programme, with a series of spacecraft which combined the functions of both the Mercury and Orion series.
It is not known whether the Orion satellites launched in recent years carried any modifications as a result of this programme or whether it was abandoned, however there has been no sign of a new satellite taking on this combined role.
It is also possible that NROL-67 could be unrelated to the main geostationary constellations; instead it could be a one-off mission or the beginning of a completely new series.
Documents leaked to the Washington Post last year hinted at a signals intelligence satellite named “Nemesis 2” which received half a billion dollars of funding during the 2011 financial year. No spacecraft could be identified as either Nemesis 2 or its presumed predecessor Nemesis 1.
One possible, though conjectural, explanation is that Nemesis 1 may have been the Prowler satellite launched in November 1990 Shuttle Atlantis, with a follow-up being launched many years later.
One other Atlas V 541 launch for the NRO is currently scheduled; NROL-42 is scheduled to fly from Vandenberg, no earlier than the 2017 financial year.
A launch from Vandenberg would be incapable of reaching a geosynchronous orbit, however the schedule could be wrong – NROL-67 was at one point also believed to be slated for a west coast launch. NROL-42’s eventual launch site could prove significant to identifying NROL-67 – indicating whether the spacecraft is a one-off mission or the first of a series.
The true nature of NROL-67 will be difficult to ascertain until the satellite has been sighted in orbit and observed over a period of several months. A team of amateur observers keep track of classified satellites, posting data on their locations and orbits online. The most likely explanation is that is a long-overdue replacement for the Mercury satellites, however this still leaves many questions unanswered.
The mission patch for NROL-67 depicts the winged horse Pegasus above the Earth, with the words “in scientia opportunitas” which translate as “In knowledge there is opportunity”.
Significantly, the depiction of the Earth prominently shows Europe, rather than North America like most US military patches.
This may indicate where the satellite will be positioned in geostationary orbit.
The launch patch, by contrast, prominently features a dragon set against clouds and a full moon.
The motto reads “forest fortuna adiuvat”, an unusual variant spelling of “fortes fortuna adiuvat”; “fortune favours the bold”.
The dragon has long been a symbol associated with the NRO’s signals intelligence missions.
While it has been suggested that its presence on a patch traditionally designed by the launch team rather than the payload team may be coincidence, symbols have in the past been seen on launch patches as well as the more prominent payload patches.
NROL-67’s patches have not been circulated as widely as those from previous missions, presumably as a result of the media backlash against the patch issued for the NROL-39 mission last December.
Coming at a time of widespread contempt for US intelligence agencies, the patch – which depicted an octopus wrapping its tentacles around the world and the words “nothing is beyond our reach” – was considered to be in bad taste.
The Atlas V used for the NROL-67 mission was AV-045. The forty-sixth Atlas V to fly, it was the second to use the 541 configuration which made use of a payload fairing with a diameter of five metres, four solid rocket motors and a Centaur upper stage with a single engine.
This configuration has flown just once before; sending the Curiosity rover on its way to Mars in November 2011.
The first stage of the Atlas is a Common Core Booster, powered by a single RD-180 engine derived from the RD-170 series developed in the Soviet Union for the Zenit and Energia rockets.
The twin-chamber RD-180 is fuelled by RP-1 propellant and liquid oxygen. Four of a maximum five Aerojet Solid Rocket Motors (SRMs) were used to augment the CCB’s thrust at liftoff on Thursday’s mission.
The second stage, the Centaur, is powered by an RL10A-4-2 engine burning liquid hydrogen and liquid oxygen. During the early stages of flight it was encapsulated, along with the payload, inside the fairing.
AV-045 sported the short variant of the five-metre fairing, measuring 20.7 metres (67.9 feet) in length and 5.4 metres (17.7 feet) in diameter.
Atlas V configurations with more than three solid rocket motors require the use of a five metre fairing, as opposed to the four metre fairing which leaves the Centaur exposed, as the upper stage would not be able to withstand the loads imparted by the additional boosters.
As such, its use does not necessarily mean that NROL-67 is too large to fit within a four metre fairing like the smaller Trumpet SIGINT satellites operated in Molniya orbits.
AV-045’s flight plan was not announced. Events in the early stages were deemed to be similar to the Mars Science Laboratory launch, with RD-180 ignition occurring at T-2.7 seconds, with the solids joining them at T-0. Around eleven tenths of a second later the Atlas lifted off to begin its ascent.
Roll, pitch and yaw manoeuvres began at around T+5.2 seconds to attain the necessary attitude to achieve its target orbit, however the early flight was close to vertical as AV-045 climbed out of the atmosphere to reach an altitude at which fairing separation can safely occur.
The solid motors burned for around 85 to 90 seconds before they separated in pairs around 27 seconds later. Fairing separation came around the three and a half minute mark, with the forward load reactor being jettisoned from the nose of the Centaur shortly afterwards. The load reactor is a device used to dampen vibrations within the fairing while it is attached, preventing acoustic damage to the satellite.
The first stage is expected to have burned out around approximately four minutes and 20 seconds after liftoff, with the last 20 seconds of the flight being made at partial thrust as the RD-180 is throttled back to limit structural loads due to acceleration. The spent CCB is expected to have separated six seconds after cutoff, with the Centaur’s RL10 engine igniting ten seconds later.
The Centaur then made two or three burns depending on the flight profile. Assuming NROL-67 goes to geosynchronous orbit, the Atlas may place it there directly, or instead the satellite might enter a transfer orbit and raise itself to the final orbit under its own power.
Direct insertion into geostationary orbit has been favoured for past NRO SIGINT launches, and is also used on some of Russia’s Proton launches. By contrast the majority of geosynchronous launches use a transfer orbit, and this approach has been used for the NRO’s Quasar satellites in the past.
Direct insertion into geostationary orbit would require a three-burn profile, while a transfer orbit could be reached in two or three burns depending on mission requirements.
A typical ascent to a transfer orbit would use two burns; the first burn, which would be significantly longer than the second, would place the spacecraft into an elliptical parking orbit, with the Centaur then restarting to increase the apogee to geostationary altitude or above. On some missions an extended coast phase may be inserted between the burns to allow a higher perigee to be achieved.
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Alternatively, a third burn could have been made separately to raise the perigee during the coast towards apogee. A direct launch into geostationary orbit would work in much the same way, except for the third burn being made five hours after launch to circularise the orbit at apogee. In order to achieve this the Centaur must carry and extended mission kit.
For a typical mission to place a satellite directly into geostationary orbit, the Centaur would make an initial burn lasting around eight and a half minutes. After coasting for nine and a half minutes, the stage would restart and burn for about 265 seconds to reach its transfer orbit.
The Centaur would then begin rolling to maintain thermal control during its extended coast phase. After five hours and seven and a half minutes of coast, the RL10 would restart for a further two minutes to place the payload into its target orbit with spacecraft separation occurring about two and a half minutes later. ULA, later on Thursday, confirmed a successful spacecraft separation.
Thursday’s launch took place from Space Launch Complex 41 at the Cape Canaveral Air Force Station, a former Titan launch pad which is the east coast home of the Atlas V. Constructed during the 1960s, the pad has previously been used by Titan IIIC, IIIE and Titan IV rockets.
Atlas rockets are assembled in the Vertical Integration Facility to the west of the launch complex and rolled out atop a mobile launch platform.
AV-045 was originally transported to the launch pad on 24 March ahead of a launch planned for the next day. Range instrumentation problems initially led to a one-day delay, however the launch slipped further after the extent of the problem became known, with the Atlas rolling back to the VIF on 27 March.
The rocket returned to the pad Wednesday in preparation for Thursday’s launch attempt. An on-time launch will allow SpaceX to fly its CRS-3 mission early next week, another launch which was delayed by the range problems.
The launch of AV-045 marks the thirty seventh Atlas mission to depart SLC-41, and the sixty-fourth launch from the complex overall. Coming a week after the previous Atlas V lifted off from Vandenberg Air Force Base, it was America’s sixth orbital launch of 2014, the third for the Atlas V and fourth for United Launch Alliance.
The next planned mission for ULA is slated for 7 May, with an Atlas V 401 deploying the NROL-33 payload. Also slated to fly from Cape Canaveral, NROL-33 is likely to be either a Quasar communications satellite or an Intruder signals intelligence spacecraft.
(Images via ULA (Ben Cooper), USAF, ULA, SpaceX, L2 Historical and NASA).
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