Screenshot from ULA Webcast of the JPSS-1 launch. Nasa sure like to keep the lights on
Mission Rundown: ULA - Delta II 7920-10 - JPSS-1
Written: December 13, 2022
One launch left on the shelf
United Launch Alliance (ULA) launched – at the third attempt – the second to last Delta II mission on Saturday, November 18, 2017 carrying the JPSS-1 weather satellite on its path to orbit from Vandenberg Air Force Base in California. Liftoff, from Space Launch Complex 2W, occurred during a 62-second window opening at 01:47 Pacific time (09:47 UTC).
The Joint Polar Satellite System (JPSS) is the nation's advanced series of polar-orbiting environmental satellites.
JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. These data are critical to the timeliness and accuracy of forecasts three to seven days in advance of a severe weather event. JPSS is a collaborative effort between NOAA and NASA.
JPSS satellites circle the Earth from pole-to-pole and cross the equator 14 times daily in the afternoon orbit--providing full global coverage twice a day.
The JPSS-1 Payload
JPSS-1, which will be renamed NOAA-20 once it is in orbit, is the newest satellite in the US National Oceanic and Atmospheric Administration’s (NOAA’s) fleet of polar-orbit weather satellites. JPSS-1 is the first of four planned Joint Polar Satellite System (JPSS) spacecraft, successors to the organization’s current-generation Polar Operational Environmental Satellite (POES) constellation.
The JPSS program grew out of the canceled National Polar-Orbiting Operational Environmental Satellite System, or NPOESS, which aimed to replace the NOAA’s POES system and the Air Force’s Defense Meteorological Satellite Program (DMSP) with a single fleet of satellites.
The 2,540-kilogram (5,600 lb) JPSS-1 satellite was constructed by Ball Aerospace, and is based around the BCP-2000 satellite bus. Expected to operate for seven years, it carries the same suite of five instruments as Suomi.
Its Visible Infrared Imaging Radiometer Suite (VIIRS), images the Earth at twenty-two visible-light and infrared wavelengths. The data it collects will help scientists to monitor a wide range of phenomena on the Earth’s surface and in the atmosphere.
Clouds and the Earth’s Radiant Energy System (CERES) FM6 is the sixth in a series of instruments designed to measure Earth’s radiation budget: the amount of radiation the planet emits and the amount of sunlight that it reflects.
CERES instruments have previously flown aboard the Terra and Aqua satellites – which carried two each – and Suomi NPP.
Photo of JPSS-1 getting packed for transport to Vandenberg Air Force Base. Strike a pose
Two atmospheric sounders – the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) – will allow the satellite to build temperature, pressure and humidity profiles of Earth’s atmosphere.
CrIS uses a 1,305-channel Fourier transform spectrometer to take readings at infrared wavelengths, while ATMS has 22 spectral channels and operates at microwave wavelengths. The atmospheric profiles produced by these instruments will aid both weather forecasting and monitoring of changes in the Earth’s climate.
PSS-1’s Ozone Mapping and Profiler Suite (OPMS) consists of two hyperspectral imagers which will be used to monitor the level and distribution of ozone within the upper atmosphere and troposphere.
The instrument will allow NOAA to monitor the recovery of Earth’s ozone layer, as well as helping to forecast ultraviolet radiation levels and to report on air quality.
The ELaNa 14 Share Ride
In addition to JPSS-1, five small satellites were aboard the launch. Four of these were being carried as part of NASA’s Educational Launch of Nanosatellites, or ELaNa, program and the ELaNa XIV mission. ELaNa is a NASA program which provides launch opportunities for mostly university payloads built to the CubeSat standard, a very common specification for nanosatellites.
EagleSat is a single-unit CubeSat which was built by the Embry-Riddle Aeronautical University. The satellite will be used to study how solid-state storage devices are affected by exposure to the radiation environment that spacecraft experience. A GPS receiver aboard the spacecraft will also allow students to track changes in its orbit over time – allowing its orbital decay to be characterized.
Another single-unit CubeSat, MakerSat-0, will study how several polymers used in 3D printing are affected by exposure to space. The satellite is a pathfinder for Northwest Nazarene University’s MakerSat project, which later aims to construct a satellite wholly in space and deploy it from the International Space Station.
Vanderbilt University’s RadFxSat-1 was built in partnership with AMSAT. A single-unit CubeSat, it will be used to investigate how electronic components are affected by radiation in orbit, helping to prove their suitability for future missions and refine their manufacturing processes. The spacecraft also carries an amateur radio transponder for AMSAT, who uses the name Fox-1B for the satellite.
The last of the ELaNa 14 CubeSats is, Microwave Radiometer Technology Acceleration, or MiRaTA, was a 5.5-kilogram (12.1 lb), three-unit CubeSat built by the Lincoln Laboratory at the Massachusetts Institute of Technology (MIT).
The satellite carries an ultra-compact microwave radiometer to be tested in orbit, as well as an experimental GPS receiver which will be used to help study the occultation of GPS signals as they pass through the atmosphere – which allows atmospheric conditions to be inferred from how the signals are affected.
MiRaTA will also demonstrate how the measurements from its GPS receiver can be used to calibrate the radiometer.
The final CubeSat aboard the launch is not part of the ELaNa program. The Buccaneer Risk Mitigation Mission (Buccaneer RRM) satellite is a three-unit CubeSat being flown in partnership between the University of New South Wales and the Australian Department of Defence’s Defence Science and Technology Group (DSTG).
The satellite is a prototype, being launched ahead of another satellite – Buccaneer – which will be used to help calibrate Australia’s Jindalee Operational Radar Network (JORN).
The Delta II Rocket Launch
Delta 378 ignited its RS-27A main engine and both verniers at T-2.7 seconds before the countdown reached T0 . At T0, six of the nine GEM-40 solid rocket motors ignited, and Delta lifted off to begin the journey into orbit.
With its six ground-lit solids burning Delta climbed quickly away from Vandenberg, reaching a speed of Mach 1 32.9 seconds after liftoff and passing through the area of maximum dynamic pressure – or max-Q – 14.9 seconds later.
The six solid motors burned for about 64 seconds. The remaining three GEM-40 motors were air-lit and also burned for 64 seconds, igniting about one and a half seconds after the ground-lit solids burned out. The ground-lit solid motors jettisoned about 86 seconds into the flight, with the air-lit motors separating at the 131.5-second mark.
After the solids separate, Delta’s RS-27A engine continued to burn until four minutes, 23.4 seconds after liftoff, when it shut down. This event is designated main engine cutoff, or MECO, and followed shortly afterward by vernier engine cutoff, or VECO. Eight seconds after MECO the first stage was jettisoned, with the second stage’s AJ10 engine ignited five and a half seconds after stage separation, beginning the first of four planned burns.
The first burn of the Delta-K second stage lasted six minutes and 1.3 seconds. About 4.1 seconds into the burn Delta’s payload fairing separated from around JPSS-1 at the nose of the rocket. The first burn established an initial parking orbit, and was followed by a 40-minute, 11.8-second coast phase before the second burn began.
Lasting twenty-four seconds, Delta-K’s second burn circularized the orbit for the primary payload, JPSS-1. Six minutes and 16 seconds after the end of the burn, JPSS-1 separated into its operational orbit.
The target parameters for this launch are a semi-major axis of 7,201.1 kilometers (4,474.6 miles, 3,888.3 nautical miles) and eccentricity of 0.001 – giving an orbit of 822.9 by 837.3 kilometers (511.3 x 520.3 miles, 444.3 x 452.1 nautical miles). This orbit will be inclined at 98.7 degrees, with an argument of perigee of 69.2 degrees.
Separation of the primary payload isn’t the end of this flight, 17 minutes 30 seconds after spacecraft separation, the Delta-K made its third burn – lasting 10.2 seconds – to adjust its orbit for deployment of the five CubeSats.
The three single-unit CubeSats were released six minutes and 29.8 seconds after the end of the burn, with the first of the three-unit satellites separating 120 seconds later and the other and 100 seconds after that.
The fourth and final burn of the Delta-K – beginning 29 minutes and 25 seconds after the last CubeSat deployment lasted 41 seconds – deorbited the upper Delta-K stage to a safe, destructive, reentry in the Ocean.
The Delta II rocket
For this mission, Delta II flew in the 7920-10C configuration.
Delta was one of the first rockets to adopt a systemic numbering system for different configurations, with the first digit denoting the type of first stage and boosters, the second digit giving the number of solid rocket boosters, the third digit representing the type of second stage and the fourth indicating the type of third stage, if one is present.
The final part of the designation gives the type of payload fairing being used, with the 10C fairing a three-meter (ten-foot) carbon composite model.
Delta II loads 10 000 gallon RP-1 - kerosene and LOX - liquid oxygen into its first stage propellant tanks which will feed the RS-27A rocket engine to generate 789 000 pounds of thrust to lift Delta II with JPSS-1 into low earth polar orbit.
The “7000-series” Delta II uses an Extra-Extended Long Tank Thor (XELTT) first stage, with three, four or nine Graphite Epoxy Motor 40 (GEM-40) solid rocket motors.
The launch was the last time Delta flew with nine solid rocket motors – the family’s most common booster configuration since the 1970s.
SRB 6, 4 and 5 are fitted with a larger nozzle given that they will perform better in altitude using those nozzles. The SRB’s no. 2 8 6 3 9 4 1 7 5 are mounted in this order on the main core booster of Delta II. That order can’t be the ignition order since 6, 4 and 5 are in the middle grouping. 7, 8 and 9 would be a natural launch order in that chase.
The XELTT, which is descended from the Thor IRBM, is powered by an RS-27A engine. Two additional Vernier motors help to steer the rocket during first stage flight.
Delta II’s second stage is a Delta-K, powered by an AJ10-118K engine, while in the 7920 configuration no third stage is present.
Both the first and second stages are liquid-fuelled, with the first stage burning RP-1 propellant oxidized by liquid oxygen and the second stage Aerozine 50 – a mixture in equal parts of hydrazine and unsymmetrical dimethylhydrazine – and dinitrogen tetroxide.
