ULA to loft Space Force missile tracking satellite in first Atlas V launch of 2021

A United Launch Alliance (ULA) Atlas V 421 is at Space Launch Complex-41 (SLC-41) at… The post ULA to loft Space Force missile tracking satellite in first Atlas V launch of 2021 appeared first on NASASpaceFlight.com.

ULA to loft Space Force missile tracking satellite in first Atlas V launch of 2021

A United Launch Alliance (ULA) Atlas V 421 is at Space Launch Complex-41 (SLC-41) at the Cape Canaveral Space Force Station ahead of its mission to loft a new Space Based Infrared System (SBIRS) military reconnaissance satellite into Geostationary transfer orbit. Liftoff of SBIRS GEO-5 is scheduled for 17:35 UTC (13:35 EDT) on Monday, 17 May.

The flight will mark the first 2021 launch of ULA’s Atlas V rocket and the second launch made by the company this year following the April launch of NROL-82 which utilized a Delta IV Heavy launch vehicle. The Atlas V is configured in the 421 variant, meaning it utilizes a 4 meter diameter fairing, two solid rocket boosters and single engine centaur upper stage.

The Space Based Infrared System

The United States Space Force’s (USSF’s) Space Based Infrared System was born during the 1991 Gulf War, when the US Military realized its missile warning capabilities were lacking and a new system would be needed in order to allow the country to quickly and accurately track short- and long-range missile launches from around the world.

Prior to SBIRS, the US military’s missile warning capabilities were provided by the Defense Support Program (DSP), a constellation of 23 satellites launched between 1970 and 2007. Although this system was useful in providing missile early warning capabilities, shortcomings experienced while using the system during the Gulf War made it clear the DSP would need to be replaced by a more advanced system.

The US Air Force later chose Lockheed Martin to build that system, which became SBIRS.

SBIRS was split into two different categories, the first being SBIRS Low (also known as SBIRS HEO) which was initially to consist of two satellites in a highly eccentric orbit known as a “Molniya orbit“. The second category was known as SBIRS High (or SBIRS GEO), initially set to consist of two satellites located in Geostationary Orbit. 

Each SBIRS GEO spacecraft utilizes a suite of two advanced sensors, allowing them to detect short- and mid-wave infrared signals, providing data which can be used to track missile launches from around the world. The constellation has very quickly proven its worth; according to Lockheed Martin, the SBIRS system detected nearly 1,000 worldwide missile launches in 2019 alone.

After the system first came online in 2013, the US Air Force awarded Lockheed Martin a set of contracts to expand the constellation, ordering a third HEO spacecraft in 2009 followed by a third and fourth GEO satellite that same year.

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  • In 2014, the US Air Force awarded Lockheed Martin a contract for a fifth and sixth GEO satellite. Contracts for GEO-7 and GEO-8 were also awarded, but those spacecraft were cancelled in 2019, and GEO-6, scheduled for launch next year, is now set to be the final spacecraft that will join the SBIRS High constellation. 

    When GEO-5 was ordered alongside GEO-6, the two spacecraft were initially supposed to be identical to the four SBIRS High satellites that have preceded them, which used Lockheed Martin’s A2100 satellite bus. 

    During the development of GEO 5 and 6, it was decided to instead use the modernized LM2100M (Modernized Military) bus, which is developed specifically for military operations.

    The LM2100M is designed to be more resilient to cyber attacks and contains an upgraded suite of power and propulsion equipment.

    The modular design of the spacecraft also allowed for a much more streamlined manufacturing process.

    Aritists impression of SBIRS GEO-5 in orbit. (Credit: Lockheed Martin)

    The launch of GEO-5 will mark the first flight of the new spacecraft design, although the US Space Force has already awarded contracts to Lockheed Martin for at least 26 satellites built on the LM2100M design, one for GEO-6, three for the branch’s Overhead Persistent Infrared (OPIR) missile warning constellation, which is set to start replacing SBIRS from 2025, and 22 for the next generation of Global Positioning System (GPS) satellites.

    Flight plan

    The ULA Atlas V 421 rocket is scheduled to liftoff from SLC-41 at 17:35 UTC, though there is an undisclosed window and the launch period is not instantaneous.

    The rocket’s first stage is powered by an RD-180 main engine and supplemented on this flight by two AJ-60A solid rocket boosters from Aerojet Rocketdyne, all together providing around 6,700 kN of thrust at liftoff according to ULA — increasing to over 7,100 kN during first minute and a half of ascent. 

    After 47 seconds of flight, the rocket will break the sound barrier and pass Mach 1, followed less than a second later by MaxQ, the period in the launch where the Atlas V will experience maximum aerodynamic pressure.

    At T+2 minutes 9 seconds into the flight, the two AJ-60A solid rockets will be jettisoned more than 30 seconds after burnout, allowing them to begin their fall back safely back to Earth. They are held by the Atlas V first stage for such a prolonged period after burnout to ensure a clean separation from the vehicle based on aerodynamics.

    The first stage will then continue to burn until T+4 minutes10 seconds, when the RD-180 will cutoff, followed six seconds later by first stage separation. The Centaur upper stage will coast for 10 more seconds before its single

    The payload fairing, which will protect the satellite as the rocket rips thought the thickest parts of the atmosphere, will be deployed at T+4 minutes 34 seconds, as the atmosphere will then be thin enough to allow for SBIRS to be safely exposed to the elements.

    At 15 minutes 06 seconds into the flight, Cenatau’s RL10C-1-1 engine will cut off, placing the vehicle into an initial parking orbit.  Almost immediately, two rideshare payloads, EZ-3 and EZ-4, will deploy from Centaur.

    EZ-3 and -4 are technology demonstration satellites for the US government testing experimental data for the US Air Force Academy.

    A 15 minute coast phase will follow, with Centaur engine reignition at T+31 minutes 06 seconds. This 3 minute 21 second burn will place SBIRS and Centaur into the mission-specific Geostationary transfer orbit, (GTO), of 925.2 x 35,753.2 km with an inclination of 21.14 degree, down from the initial 28.5 degree inclination at liftoff.

    From this orbit, the spacecraft will begin the process of moving itself into its planned Geostationary orbit location.

    Lockheed Martin will then officially hand over control of the spacecraft to the USSF’s Overhead Persistent Infrared Battlespace Awareness Center at Buckley Air Force Base, Colorado, who will control it from their on.

    Space Launch Delta 45

    Besides marking the first flight of a new generation of missile warning satellites, the mission also marks the first launch since the US Space Force re-named the 45th Space Wing to Space Launch Delta 45.

    Since the early 90s, all launches from Florida’s eastern range have been managed by the 45th Space Wing, initially a US Air Force unit that was transferred over to the Space Force when the branch was created in late 2019. 

    As part of the Space Force’s restructure, moving it away from its Air Force heritage as it establishes its own vocabulary and structure, the 45th Space Wing was renamed Space Launch Delta 45, alongside the Western Range’s 30th Space Wing which was renamed to Space Launch Delta 30.

    (Lead image: Atlas V on the pad ahead of SBIRS GEO-5. Credit: Stephen Marr for NSF)

    The post ULA to loft Space Force missile tracking satellite in first Atlas V launch of 2021 appeared first on NASASpaceFlight.com.

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    Starship SN15 patiently awaits a decision – The Road to Orbit

    Following its successful launch and landing, Starship SN15 has been placed back onto a launch… The post Starship SN15 patiently awaits a decision – The Road to Orbit appeared first on NASASpaceFlight.com.

    Starship SN15 patiently awaits a decision – The Road to Orbit

    Following its successful launch and landing, Starship SN15 has been placed back onto a launch mount for inspections and a potential re-flight. The upcoming test schedule will be focused on providing a green light for an orbital attempt that has already been filed with the FCC (Federal Communications Commission).

    Starship SN15:

    SpaceX finds itself in a unique position of having a successfully landed Starship still in one piece out at the launch site.

    Following a few days sitting on the landing pad it touched down on, SN15 has now been lifted onto Launch Mount B, having launched from Mount A. This marked the first time the same Starship took up residence at both of the suborbital launch mounts.

    Although Elon Musk has not advanced on his initial comment SN15 might fly again, the decision is likely pending a full inspection of the vehicle, including its engines, which will be allowed for now that it is back on a launch mount.

    SpaceX SN15 Updates
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  • This will allow for additional access to the aft of the vehicle, following what is understood to be positive results from initial inspections conducted while the vehicle was sat on the landing pad.

    As for SN15, numerous options remain open to SpaceX, from reflying the Starship to conducting ground tests including cryotesting the vehicle in what is a post-flight configuration or even Static Fire testing if the option of another flight is removed.

    Reflying SN15 would be an attractive option to SpaceX, a milestone that caters towards the company’s reusability mantra. It would also allow for additional flight data that could be incorporated into the potential flight of SN16.

    That next Starship id deep into preparations for roll to the launch site, having been stacked inside the High Bay. However, final processing – such as installing aero covers over the flaps – has been placed on hold pending SpaceX defining a clear path ahead.

    Starship SN16 waits in the High Bay – photo via Mary (@bocachicagal) for NSF.

    Should SpaceX opt to fly SN16, it will likely be to the full 20 kilometer high altitude hop target.

    While Starbase’s impressive production cadence has been a focal point over recent months, the usual full occupancy of the Mid Bay has been lacking of late. This again points to SpaceX finding itself at a decision point on the test schedule.

    Most of the new stacking operations have been related to the build-up of Ground Support Equipment (GSE) tanks that will take their turns rolling down Highway 4 to become part of the Orbital Launch Site (OLS).

    Orbital Launch Site:

    Ongoing construction work at the OLS is also playing into Starship test schedule evaluations, with any near-term Starship test and flight operations requiring the site to be clear of workers.

    Such operations would also require two huge cranes to be rolled back down Highway 4 one at a time, namely the LR 1600/2 (community nicknamed “Tankzilla”), which was recently used to place Starship SN15 on to Mount B, and the LR 11350 (which SpaceXers nicknamed “Frankencrane” due it being a collection of various crane appendages).

    Notably, the LR 11350 would require disassembly of its boom before any such move away from the launch site.

    Parts for another huge crane, the LR 11000, also began arriving on a fleet of trucks Sunday.

    Both cranes are being staged to stack the numerous sections of the Launch Integration Tower that have already begun to rise out of the ground next to the launch mount.

    Additional sections of the Launch Tower – prefabbed off-site – are being assembled at the Old Gas Well site, ready to be transported to the OLS for stacking via the use of the new cranes.

    Pre-fab OLS Launch Tower sections – via Mary (@bocachicagal) for NSF

    While the support structures for the Super Heavy/Starship stack are being built, work on the OLS tank farm is well underway. Several commodity tanks have already been installed, along with two large GSE stainless steel tanks that have been constructed using similar methods to those utilized with Starship structures.

    A third GSE tank is also ready to roll down Highway 4, while GSE 4 is currently being stacked. The GSE tanks will be cocooned in the cryo tank shells, currently also under construction at the Old Gas well site. These will add insulation for the cryogenic fluids in the GSE tanks, with gaseous nitrogen used as insulation between the two tank layers.

    The infrastructure is being prepared ahead of welcoming Super Heavy BN3 to the pad.

    Super Heavy BN1 was stacked in the High Bay but scrapped soon after when SpaceX opted to change the design of the booster, specifically the arrangement of the LOX (Liquid Oxygen) and CH4 (Liquid Methane) tanks.

    Sections for BN2 and BN2.1 were also spotted. However, both were sections catering to pathfinder objectives. As such, BN3 is expected to be the first stacked Super Heavy to be rolled to the OLS.

    The first sections of the BN3 booster have already been staged for stacking inside the High Bay.

    BN3 (behind SN16) inside the High Bay – via Mary (@bocachicagal) for NSF

    As reported from recent documentation, SpaceX is targeting the flight of Super Heavy BN3 with Starship SN20 for the orbital test flight. While the designated vehicles for the mission may change over the coming weeks, a sign the test flight is deep into the planning phase was observed with the publication of a filing with the Federal Communications Commission (FCC).

    According to the FCC overview, the flight profile calls for staging between the Super Heavy and Starship at approximately 170 seconds into flight.

    “The Booster will then perform a partial return and land in the Gulf of Mexico approximately 20 miles [32.1 km] from the shore. The Orbital Starship will continue on flying between the Florida Straits. It will achieve orbit until performing a powered, targeted landing approximately 100 km (~62 miles) off the northwest coast of Kauai in a soft ocean landing.”

    FCC slide of the Starship Splashdown area.

    As confirmed by the document, neither Super Heavy nor Starship will be returning to the launch site. Furthermore, Starship will perform its well-known bellyflop, flip, and landing maneuver over the Pacific and will be expended in the ocean.

    Super Heavy will have a full set of Raptors; the number has likely changed since the 2019 Starship update when Super Heavy was to have 28 engines. The outer ring of engines will not have Thrust Vector Control while the inner ones will. Starship is set to utilize six Raptors, three sea-level and vacuum-optimized.

    As such, this test flight alone will require a large stock of Raptor engines.

    While Raptors arriving into Boca Chica are in the SN50 and SN60 range, SpaceX’s test site in McGregor is hosting engines in the SN70-80 range, while it is understood that production in Hawthorne is working on engines past SN150 — with a current shipping rate of several Raptors per week.

    To support a fully expendable launch with over 30 Raptors, SpaceX has drastically increased the Raptors’ production rate. Following the new clean Raptor design, SpaceX has increased production, while McGregor is ready to cater to the increased test cadence with a new vertical engine test stand.

    Via NSF’s Gary Blair in the L2 McGregor section, new stand on the left, current stand on the right

    Demand for Raptors, not least with the first orbital test flight being expendable, will only increase as SpaceX pushes through to future missions with additional Super Heavy and Starship flights.

    While the SN20 and BN3 combo will be first in line for orbital flight, it’s expected that the subsequent boosters and ships will pair up accordingly, SN21 with BN4, SN22 with BN5, and SN23 with BN6. In addition, it’s understood that a major design upgrade is set to come with the SN24/BN7 pair.

    By the time SpaceX has moved into the SN24 range, there is the potential of minimal availability on SpaceX’s two ocean platforms.

    Phobos and Deimos are currently being converted for the task of hosting Super Heavy launch and landing. Notably, the vehicle’s landing will also see the introduction of the catching system, with two large mechanical arms grabbing the booster during the end of the landing burn.

    The OLS – which will eventually host two Super Heavy launch mounts – will also sport the catching arms on the launch integration towers.

    While this ambitious test program requires numerous successes in a relatively short period compared to most of the space flight industry, SpaceX has already proven its ability to cater to such a high test cadence.

    SpaceX Boca Chica was nothing more than a tent by the beach just two years ago. Now, it’s a sprawling production site and dual launch facility — with a new name.

    The facility was officially christened Starbase this weekend, with the installation of signage.

    Photos and videos provided by Mary (@bocachicagal). Additional information and article assistance provided by: Trevor Sesnic, Ryan Weber, Alejandro Alcantarilla Romera, Evan Packer, Jasper Nijhuis, Nicholas H, and Liam-Amon Kroke.

    For live updates, follow NASASpaceFlight’s Twitter account and the NSF Starship Forum Sections.

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    The post Starship SN15 patiently awaits a decision – The Road to Orbit appeared first on NASASpaceFlight.com.

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