Screenshot from ULA Webcast of the launch of JPSS-2. Last Atlas to fly without boosters
Mission Rundown: ULA - Atlas V 401 - JPSS-2
Written: December 8, 2022
A Tincan with a Rubber Boat flies south
United Launch Alliance (ULA) will launch a satellite contracted by NOAA - the National Oceanic and Atmospheric Administration. The mission Joint Polar Satellite System-2 (JPSS-2) is now set for launch Thursday, Nov. 10 at 1:25 a.m. PST (0925 UTC).
The mission will lift off aboard a Atlas V 401 rocket from Space Launch Complex-3 at Vandenberg Space Force Base in California. JPSS-2 is a new generation polar-orbiting operational environmental satellite system.
Also aboard the Atlas V 401 rocket will be the secondary payload, NASA’s Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID). LOFTID will demonstrate inflatable heat shield technology for atmospheric entry and re-entry. This technology could enable a variety of proposed NASA missions to destinations such as Mars, Venus, and Titan, as well as returning heavier payloads from low-Earth orbit.
Landing/Crash areas reserved for the Atlas 401 two stages and LOFTID. JPSS-2 stays up though
The Atlas rocket family, which for decades was a cornerstone of the US launch market, is set to end its west coast career as ULA prepares for a transition to their next-generation launch vehicle, Vulcan.
In addition to being the last Atlas to launch from Vandenberg, JPSS-2 is also the last flight of Atlas’s four-meter diameter payload fairing.
Now, 63 years after the first flight of an Atlas from California, the rocket bows out of operations from Vandenberg as ULA ends the Delta and Atlas rocket lines in favor of a single system in Vulcan.
After JPSS-2, only 19 east coast Atlas rocket flights remain before the line’s retirement: seven Starliner crew flights to the ISS in the N22 configuration, and 12 flights in the 551 configuration, including nine flights for Project Kuiper, USSF-51 for the US Space Force, ViaSat-3 EMEA, and NROL-107 for the National Reconnaissance Office.
The JPSS-2 Payload
JPSS-2 is part of the Joint Polar Satellite System, the most recent generation of US polar-orbiting, non-geosynchronous, environmental satellites for the National Oceanic and Atmospheric Administration (NOAA). The satellites themselves are developed by NASA for NOAA, the latter of which oversees their operation.
Upon reaching orbit, JPSS-2 will join the first two satellites of the program, Suomi NPP, launched in October 2011, and JPSS-1, which launched in November 2017 and was renamed NOAA-20 after reaching its final orbit.
JPSS-2 will operate in a Sun-synchronous orbit of 824 kilometers altitude inclined 98.8° to enable global coverage twice a day. Liftoff was set in a window to allow for an ascending node crossing of the equator, per mission requirements.
The predecessor JPSS-1 was built by Ball Aerospace. The JPSS-2 satellite was built by Northrop Grumman and is based around its LEOStar-3 satellite bus.
LEOStar-3 will be responsible for the control and stabilization of the satellite, which will be accomplished via three-axis, zero momentum bias, and nadir pointing. When pointing, JPSS-2 will have 0.13° arc second control and 0.02° arc second knowledge. Huu?
JPSS-2 will take up or claim 2,930 kg against a not-to-exceed launch mass of 3,198 kg. JPSS-2 hosts four primary instruments including the Advanced Technology Microwave Sounder (ATMS), the Cross-track Infrared Sounder (CrIS), the Ozone Mapping and Profilers Suite (OPMS), and the Variable Infrared Imaging Radiometer Suite (VIIRS).
The ATMS instrument will monitor atmospheric moisture and temperature profiles for real-time weather forecasting and measurements for climate monitoring.
CrIS will enable high-resolution 3D moisture, pressure, and temperature profiles, and allow for better modeling in both short and long-term weather forecasting. Improve knowledge of the regular El Niño and La Niña climate fluctuations.
OMPS will continue a near-30-year records process of monitoring the ozone layer’s complex chemistry and its destruction around the troposphere.
VIIRS will provide global maps in the visible and infrared spectrums of land, ocean, and atmospheric conditions at high temporal resolution. VIIRS will upgrade the Advanced Very-High-Resolution Radiometer from previous NOAA satellites.
Two additional JPSS satellites with a 7 year life expectancy are currently being built by Northrop Grumman after the company won the contract to build JPSS-2, -3, and -4. JPSS-3 is targeted to launch in 2024, followed by JPSS-4 in 2026.
The LOFTID Payload
Joining JPSS-2 as a secondary payload is NASA’s LOFTID spacecraft, otherwise known as the Low-Earth-Orbit Flight Test of an Inflatable Decelerator. LOFTID will demonstrate how a large aeroshell, six meters in diameter, performs during reentry from low Earth orbit.
Utilizing an inflatable aero decelerator/heatshield such as LOFTID comes with numerous potential applications for the size and mass of future interplanetary missions that require larger heatshields than the rigid aeroshell casings current designs utilize.
An exploded view of the LOFTID re-entry vehicle shows all of the segments. Credit: NASA
Moreover, inflatable heat shields could also enable the recovery of large rocket stages, such as the engine section of ULA’s upcoming Vulcan rocket. They could also permit NASA to bring more mass back from the International Space Station, as well as enable the return of large-scale in-space manufacturing assets.
NASA specifically notes, too, that this kind of technology is “scalable to both crewed and large robotic missions to Mars.” In other words: Let’s see it work first.
The Rocket Launch
The launch countdown began with the loading of liquid oxygen onboard Atlas V. The rocket was already fueled with RP-1 kerosene two days before during the completed WDR.
Throughout the last four minutes of the countdown, ULA launch teams monitored the health of the rocket and spacecraft.
At T – 2 seconds, the RD-180 engine ignited, and the rocket lifted off at T-0.
At T+1:20, Atlas V broke through the sound barrier.
At T+1:27, Atlas V experienced Max-Q, short for maximum aerodynamic pressure. Max-Q occurs when the aerodynamic loads on the vehicle are at their highest during ascent.
Propellant levels in the first stage were depleted at T+4:02, and the RD-180 engine was commanded to shut off in an event called booster engine cutoff (BECO). Spacecraft separation followed six seconds later, at T+4:08.
Centaur upper stage ignited its RL-10 engine thrice, starting with main engine start 1 (MES-1) at T+4:18. Payload fairing jettison occurred at T+4:26 just eight seconds after MES-1. MECO-2 happened at T+17:09.
JPSS-2 weather observatory for NOAA and NASA deployed from the Centaur upper stage at T+28:09, kicking off its 7-year mission in its polar sun synchronous orbit.
In the minutes following separation from Centaur, JPSS-2 unfolded its solar array and began generating power to test and run its instruments and internal systems.
LOFTID rides below JPSS-2 in the payload stack and is packed within a bag 7.4 feet (2.3 meters) tall and 4.3 feet (1.3 meters) in diameter.
Centaur will execute another speed reducing burn to reach an elliptical transfer orbit that lowers the altitude on the other side of the orbit. A subsequent third burn places LOFTID on its desired re-entry flight path to test the heat shield against the intense conditions of atmospheric re-entry.
After achieving the ballistic re-entry trajectory, Centaur re-orients, the ULA-designed launch canister encasing LOFTID in its stowed configuration is ejected and the upper stage issues a signal to "wake up" LOFTID to begin the inflation process using gaseous nitrogen.
Centaur will do a spin up maneuver to give LOFTID spin-stabilization before releasing the Re-entry Vehicle about 75 minutes after liftoff.
Measuring an inflated 19.7 feet (6.0 meters) in diameter and 5.9 feet (1.79 meters) tall, the Re-entry Vehicle plunges through the atmosphere over the Pacific Ocean, its flexible heat shield seeing temperatures in excess of 4,000 degrees F (2,200 degrees C).
This Flexible Thermal Protection System (FTPS) is made of a fabric outer layer capable of withstanding the surface temperatures, insulation layer that reduces the heat transmission to the inflated structure, and a gas barrier that prevents any hot gas from flowing through.
The reentry and landing was successful. The flight data will be reviewed for a year.
The Atlas V 401 rocket
The Atlas V 401 booster core used for this mission is AV-098.
The AtlasV 401 rocket split in its major parts with JPSS2 and LOFTID aboard on its last flight
Atlas V underwent a Wet Dress Rehearsal (WDR). A WDR is one of the final major tests of all the systems on the Atlas V, which includes fueling the rocket as if it is about to launch. 25000 gallons of refined RP-1 to be exact.
The 4.2-meter payload fairing encapsulating the JPSS-2 payload was transported from the Integrated Processing Facility (IPF) to SLC-3E and was integrated with the Atlas V.
With Centaur hydrazine load complete. The RCS thrusters on the Centaur stage are using hydrazine as a monopropellant during orbit insertion.
The reaction control system (RCS) also provides ullage and consists of twenty hydrazine monopropellant engines located around the stage in two 2-thruster pods and four 4-thruster pods. For propellant, 150 kg (340 lb) of Hydrazine is stored in a pair of bladder tanks and fed to the RCS engines with pressurized helium gas, which is also used to accomplish some main engine functions.
A Launch Readiness Review - LRR, led by NASA Launch Manager Tim Dunn, assessed the readiness of rocket, payload, and mission assets, and heard technical overviews of the countdown and the flight.
The teams polled and gave a unanimous “ready” status for launch.
Space is incredibly cold. All heat vanishes from every part of the Centaur, especially the propellant. Liquid hydrogen and oxygen both can freeze solid. Pipes can plug up and be useless in a startup sequence and fuel pumps don’t like huge chunks of ice going through them. That is the main problem during long duration missions.
This Atlas V mission is only required to do three Centaur burns. The flight design of the JPSS-2 and LOFTID missions doesn’t need more.
The third and final burn by the Centaur's RL10C-1-1 cryogenic main engine executes a deorbit maneuver after nearly one orbit after liftoff to dispose of the stage in a safe manner that does cause an uncontrolled re-entry.
The Centaur stage is capable of up to twelve restarts, but is limited by propellant, orbital lifetime, and mission requirements. Combined with the insulation of the propellant tanks, this allows Centaur to perform the multi-hour coasts and multiple engine burns required on complex orbital insertions.
Facts on the Atlas V launch vehicle
Height of Atlas V 401: 191 feet (58.2 meters)
Fuel onboard: 344 472 liter - 91,000 gallons of liquid propellant
First stage Atlas: 25,000 gallon RP-1 - 48,800 gallon LOX
Second Stage Centaur: 13,050 gallon LH2 - 4,150 gallon LOX - 12,300 LH2?
LOX+LH2 = 66,000 gallon of cryogenic liquid propellant
150 kg (340 lb) of Hydrazine is stored in a pair of bladder tanks
Helium storage tanks: Unknown so far
Mass at liftoff: 750,000 pounds (340,000 kg) - Circa
Thrust at liftoff: 860,200 pounds (9.0 mega-Newtons) - Circa
Orbit: Sun Synchronous Polar Orbit - 511 x 512 miles (822 x 824 km)
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