Screenshot from ULA Webcast of the NROL-45 launch . The early morning commute is murder
Mission Rundown: ULA - Delta IV M+5,2 - NROL-45
Written: January 3, 2023
That’s not the right way down
United Launch Alliance’s Delta IV rocket was launched with the NROL-45 payload for the US National Reconnaissance Office on Wednesday morning February 10, 2016.
Liftoff, from Space Launch Complex 6 - SLC-6 on Vandenberg Air Force Base in California, was at 03:40 local time (11:40 UTC), the opening of its launch window.
Flying in the Medium+(5,2) configuration, the rocket is carrying out the classified NRO Launch 45 (NROL-45) mission for the National Reconnaissance Office (NRO).
Although the NRO keeps most details of its satellites and their missions classified, analysis of the information that is publicly available and comparison with previous missions often allows inferences to be made as to the nature of the spacecraft.
Delta IV M+5,2 222 degree flight path with two SRB’s, two fairings halves and
the core booster crash sites 100, 1000 and 2400 km ±10-100 km downrange
Navigation warnings in effect at the time of the launch suggest that the rocket will fly to the southwest, along an azimuth of approximately 222 degrees which would result in an orbit with an inclination of around 123 degrees.
Termed a retrograde orbit, a course at this inclination results in the satellite orbiting in the opposite direction to the rotation of the Earth.
As a result of this, the NROL-45 payload is almost certainly the fourth Topaz satellite, bound for a retrograde low Earth orbit to begin a radar reconnaissance mission.
The Topaz series is a replacement for the earlier satellites, named Lacrosse or Onyx, which were launched between 1988 and 2005.
Larger than Topaz, the first Lacrosse was deployed from Space Shuttle Atlantis during 1988’s STS-27 mission while the remaining satellites launched on Titan IV rockets.
The NROL-45 Payload
NROL-45 delivered the forth satellite in this constellation, which is presumably a FIA-Radar (Future Imagery Architecture - Radar) component of the FIA system.
They are the successors of the Onyx radar satellites. In 2013 information leaked out, which indicates that the Byman codename is Topaz. No details have been published.
Going against the earth's rotation gives you a higher ground speed. I am not a radar expert, but my understanding is this provides a higher Doppler shift on the return signal leading to better resolution.
This satellite is presently a lot fainter ‘than’ operational FIA Radars. This behavior was also seen in the days after the launch of the other FIA Radars.
For this FIA Radar 2, satwatcher Scott Tilley noticed a dramatic brightening in the first few days after launch, suggesting the deployment of the radar antenna.
The Delta IV M+5,2 Launch
The Delta IV launch saw its first stage ignite its RS-68A engine five and a half seconds before the countdown reached zero, with booster ignition and liftoff occurring at the zero mark in the count.
Climbing out over the Pacific, Delta 373 reached Mach 1, the speed of sound, approximately 50 seconds after liftoff. About twelve seconds later it passed through the area of maximum dynamic pressure, or Max-Q.
The twin GEM-60 motors augmented the first stage for the first hundred seconds of the flight, before depleting their solid propellant and burning out. About ten seconds later the spent motors jettisoned from the vehicle.
About three and a half minutes after launch, with Delta 373 in the atmosphere, the payload fairing separated from around the NROL-45 payload at the nose of the rocket. Once the fairing has separated no further information about the mission will be released by the NRO or United Launch Alliance – other than confirmation as to whether the launch was successful or not.
It is expected the Common Booster Core continued to burn until about four minutes and six seconds after launch; with stage separation occurring six seconds later. Following separation, the second stage RL10 engine will have deployed its extendable nozzle ahead of ignition, which would have taken place thirteen seconds after staging.
Timings for the second stage burns are not known, however the first is likely to be longer; around twelve and a half minutes in duration. After this the flight will enter a coast phase before the upper stage restarts for a shorter burn – likely to last around 14 seconds – about an hour later.
Once this burn is complete, NROL-45 will separate from the rocket. The target orbit for Wednesday’s mission will be close to the Topaz satellites’ operational orbits, which are roughly circular at altitudes a little below 1,100 kilometers (680 miles, 590 nautical miles).
After separation the DCSS will perform a third burn to deorbit itself, with reentry expected over the Indian Ocean during its second revolution.
The Delta IV M+5,2 Rocket
The Delta IV launched on Wednesday sported the flight, or Delta, number 373. Flying in the Medium+(5,2) configuration it consists of a single Common Booster Core (CBC) first stage powered by an RS-68A engine. The stage burns liquid hydrogen propellant, oxidized by liquid oxygen.
Attached at the base are a pair of GEM-60 solid rocket motors which provide additional thrust during the early stages of ascent.
Orbital ATK provided two 60-inch diameter Graphite Epoxy Motors (GEM-60) for the Delta IV rocket. The 53-foot-long solid rocket boosters burned for 90 seconds and provided more than 560,000 pounds of thrust.
Orbital ATK produced the SRB’s at its Magna, Utah facility, where it has manufactured 76 GEM-60s for the Delta IV launch vehicle since the initial flight in 2002.
The second stage, a five-meter Delta Cryogenic Second Stage (DCSS), is powered by an RL10B-2 engine which burns the same combination of cryogenic propellants as the first stage. The DCSS is restartable and is expected to make two burns prior to spacecraft separation and subsequently deorbit itself.
The Delta IV M+5,2 stands 225 feet tall, weighs 750000 pounds fully fueled. The RS-180A and two GEM-60 SRB’s produce 1.5 million pounds of thrust.
Delta IV M+5,2 split in its major parts. Some details are inserted in the graphic about these parts
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