Following Starship SN15’s success, SpaceX evaluating next steps toward orbital goals

SpaceX is considering numerous options for the upcoming Starship test schedule as the goal of… The post Following Starship SN15’s success, SpaceX evaluating next steps toward orbital goals appeared first on NASASpaceFlight.com.

Following Starship SN15’s success, SpaceX evaluating next steps toward orbital goals

SpaceX is considering numerous options for the upcoming Starship test schedule as the goal of reaching orbit by the summer becomes increasingly realistic.

Following Starship SN15’s successful test, options include reflying the vehicle to achieve key reusability objectives, launch SN16 to a higher altitude, or push straight through to orbital testing on Super Heavy.

Starship SN15:

Testing numerous modifications to the vehicle, Starship SN15 validated the improvements by conducting a smooth launch site campaign without the need to swap out a Raptor engine following its static fire tests.

Once SN15 was pressed into the countdown, marked by the visible sign of the CH4 (Liquid Methane) condenser being turned on, the count proceeded smoothly without any obvious mini-holds observed during previous launches.

Rising into a thick cloud layer under the power of Raptors SN54, SN61, and SN66 – along with some intermittent onboard views as a likely result of the thick clouds – most of the powered ascent was obscured from view.

The vehicle once again conducted the hover before then flipping to transition for the “bellyflop” return to the launch site, with another stable descent with good control via its aero surfaces. This element of flight has been one of the key successes per Starship’s initial test objectives.

SpaceX SN15 Updates
  • SpaceX Super Heavy/Starship Section
  • L2 SpaceX Section
  • Click here to Join L2
  • Per SpaceX’s Jon Insprucker’s pre-launch commentary,  SN15 was expected to conduct a three-engine flip, followed by a single-engine landing. However, onboard views showed two engines relit for the flip, remaining on through to touchdown.

    No official reason has been provided, although Starship’s flight computer does hold the option to alter the engine ignition sequence. In addition, it has been suggested that one engine may have suffered an issue during ascent, resulting in SN15 opting not to select that engine for the relight ahead of landing.

    SpaceX Chief Designer Elon Musk had previously referred to an option-based selection process, specifically on the point of redundancy. For example, Starship can relight all three engines, then immediately deselect the engine with the least lever arm as a way of ensuring the maneuver is completed.

    Pending official information, the end result will be considered a bonus based on SN15 ultimately succeeding with the flip and landing via the two selected engines.

    Although there was also a small fire near the aft of the vehicle post-landing, pad fire suppression hoses successfully put out the flames as the vehicle conducted safing operations, as observed via the well-known double depress vent.

    Now, with SN15 secured on the landing pad, SpaceX engineers will be able to fully examine a flown Starship, which will provide valuable data for the test program.

    It was considered as likely, based on the numerous Starships waiting in the wings, that SN15 would be retired to become a lawn ornament at SpaceX Starbase, or even scrapped, as seen with the 150-meter hop twins, SN5 and SN6.

    Then Musk tweeted a potential plan to refly SN15.  His use of “might” also provided clues into SpaceX’s often fluid plans involving Starship testing.

    If the option is taken, reflying SN15 will achieve another required milestone for Starship testing, given this is one of the vehicle’s unique selling points. Eventually, Starship will become rapidly reusable, with the ability to relaunch the same day as landing.

    Also, during SpaceX’s pre-launch coverage of Falcon 9 B1051-10’s Starlink mission, an overview of SN15’s flight was provided along with the words “stay tuned for additional test flights in the days ahead” – as much as that could be just a case of generic wording.

    Starship SN16 and SN17:

    Over at the Production Site, Starship SN16 has continued to be prepared inside the High Bay.

    Following the mating of its nosecone, all of its aero surfaces have now been installed, technically ready to make the roll down Highway 4 to the launch site.

    Latest overview via @_brendan_lewis on Starship/Super Heavy Section Status.

    Numerous options are on the table, ranging from delaying SN16’s campaign until after SN15 reflies, through tasking SN16 with a higher altitude target of 20 km, through to simply not flying the vehicle per a potential acceleration of moving to the orbital-class vehicles.
    Notably, SN16 was moved deeper into the High Bay on Saturday, likely to make room for the stacking operations of the next Super Heavy prototype that will be required for the orbital tests.

    The latter option would also impact SN17, which currently has its sections prepared for stacking operations – with the SN17 mid-LOX section recently staged outside the Mid Bay after pre-stacking work.

    While opting against flying at least a few more Starship hops before orbital attempts may seem unpalatable to some observers, there is evidence of SpaceX being highly focused on pushing to orbit.

    Orbital Starship:

    As previously reported by NASASpaceflight.com – and confirmed as “That’s our goal” by Musk on Twitter, the first orbital flight was cited in documentation as launching “with a goal to get to orbit by July 1”.

    That documentation noted it would involve Starship SN20 on Super Heavy BN3.

    Starship SN20 is already being assembled. It will be a key watch item to see how many TPS (Thermal Protection System) tiles they will receive – as will be required on the windward side of the vehicle to cope with the heat of re-entry.
    However, as with Super Heavy BN3, the aforementioned fluid nature of SpaceX’s Starship planning could alter which vehicle takes the leap to orbit.

    BN3 sections have already been spotted by Mary (@bocachicagal), along with BN2 and even BN2.1 sections, which may likely involve a Super Heavy – and/or Test Tank – for ground testing to pave the way for BN3’s launch.

    Orbital Launch Site:

    While vehicle hardware is being staged at the Production Site, the ever-changing skyline down Highway 4 at the Launch Site visually portrays SpaceX’s orbital aspirations.

    A huge amount of work continues to occur next door to Starship’s current home, with the Orbital Launch Site (OLS) working on the installation of GSE (Ground Support Equipment) and the huge Launch Integration Tower.

    The tower will be the tallest structure in the area when complete, with the base and opening section already constructed while additional sections are being fabricated ahead of rolling to the OLS for installation.

    It has been speculated that any potential leap from SN15 to the orbital attempt would have added benefits of mitigating disruption to the OLS construction efforts.

    Numerous pieces of the Super Heavy pad still need to be assembled in-situ, with the launch table currently at the production site, along with additional GSE that will be required to cater for the thirsty Super Heavy booster.

    The Launch Tower will also sport a crane for mating Starship atop Super Heavy and eventually large mechanical arms that will “catch” the booster when it returns to the launch site.

    The latter is not expected to occur during the first few flights, likely resulting in SpaceX undertaking the path it used during the first Falcon 9 booster landings, with a soft touchdown on water.

    Raptor Supply:

    A major bonus of SN15’s safe landing was the recovery of the three Raptors it flew with. They will provide priceless post-flight data on performance in tandem with the information beamed back to launch control via live telemetry.

    However, it can’t be understated how valuable hands-on examination of the engines will be for the test program, along with the allowance for potentially reusing them on future flights.

    Regardless, SpaceX’s Starship program will require a huge supply of engines, not least the Super Heavy boosters, each of which will require a stock of 28 engines per booster.

    Although production status at Hawthorne in California is unknown, test capability at SpaceX McGregor is being expanded.

    SpaceX tests Raptors in two horizontal test bays while the converted tripod stand caters for vertical test firings. In addition, McGregor recently started construction of a new test stand next to the horizontal stand. In typical SpaceX fashion, this new dual-bay stand has been all but completed in a matter of weeks.

    Via NSF’s Gary Blair in the L2 McGregor section, a local who flies past the test site at around 3,000 feet AGL, a Raptor has already been seen in one of the bays on the new stand, likely for fit checks.
    The current horizontal stand has already seen at least two Vacuum optimized Raptors tested, which also shows how far in advance SpaceX is has been moving to lay the path for taking Starship on orbital missions.

    The only question is schedule planning, which can change almost by the day. However, with SN15 achieving the latest milestone, SpaceX’s “Test, Fly, Fail, Fix, Fly” approach is clearly working and continues to be fascinating to follow.

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

    **Support NSF’s youtube channel by subscribing and/or joining here**

    Grab some cool gear along with the ability to support our content: https://shop.nasaspaceflight.com/

    The post Following Starship SN15’s success, SpaceX evaluating next steps toward orbital goals appeared first on NASASpaceFlight.com.

    Source : NASA More   

    What's Your Reaction?

    like
    0
    dislike
    0
    love
    0
    funny
    0
    angry
    0
    sad
    0
    wow
    0

    Next Article

    SpaceX flies historic 10th mission of a Falcon 9 as Starlink constellation expands

    SpaceX conducted the historic 10th flight of a Falcon 9 rocket booster on the Starlink… The post SpaceX flies historic 10th mission of a Falcon 9 as Starlink constellation expands appeared first on NASASpaceFlight.com.

    SpaceX flies historic 10th mission of a Falcon 9 as Starlink constellation expands

    SpaceX conducted the historic 10th flight of a Falcon 9 rocket booster on the Starlink V1.0 L27 mission Sunday. The mission launched from SLC-40 at Cape Canaveral Space Force Station on 9 May at 02:42 EDT / 06:42 UTC with an 80% positive launch weather and a “low risk” for recovery weather.

    This mission marked SpaceX’s 14th orbital launch in 2021, the 11th Starlink flight this year, and SpaceX’s second orbital launch and third flight overall in less than five days this month.

    Starlink is SpaceX’s global internet constellation which aims to deliver fast, low latency, and inexpensive internet to locations where ground based internet is either unreliable or completely unavailable.

    Starlink Constellation Progress 

    SpaceX is currently filling the first shell of Starlink located in a 550 km circular orbit with an inclination of 53 degrees. Once complete, the first shell will consist of 1,584 operational satellites across 72 orbital planes with 22 satellites per plane. Prior to this mission, the shell contained approximately 1,456 operational working satellites, of which about 882 are in their final orbit, meaning this is the third-to-last Starlink launch before all Starlinks for the the first shell are in space. 

    However, it will take a few months for all of the first shell satellites to reach their operational orbits; once that occurs, Starlink will cover approximately ~80% of Earth’s surface. 

    Once all the satellites in the first shell are in orbit, SpaceX will begin building out additional orbital shells that will increase bandwidth and achieve 100% global coverage thanks to some satellites in polar orbits.

    Overall, the first phase of the Starlink constellation will consist of approximately 4,408 satellites, in the following shells:

    Inclination (°) Orbital Altitude (km) Number of Satellites
    Shell 1 53.0 550 1,584
    Shell 2 53.2 540 1,584
    Shell 3 70.0 570 720
    Shell 4 97.6 560 348
    Shell 5 97.6 560 172
    The two polar shells will both reside at the same inclination and the same altitude but will have a different number of planes for the Starlinks to reside in. Shell 4 will have six orbital planes with 58 satellites per plane while Shell 5 will consist of four orbital planes with 43 satellites in each.

    According to Gwynne Shotwell, SpaceX will begin conducting regular Starlink launches into the polar shells beginning in July. These missions are expected to launch from SLC-4 East at Vandenberg Air Force Base, California. It is understood that these missions will coincide with the continued launch of Starlink satellites from Florida to lower inclinations.

    History of Reuse

    For this mission, SpaceX used the Falcon 9 booster B1051-10 with the “-10” signifying the booster’s 10th flight.

    Booster B1051 is the second oldest operational first stage booster in the Falcon 9 fleet, debuting in prominence with the uncrewed Demo-1 flight of Crew Dragon to the International Space Station on 2 March 2019. During its life, it has flown the following missions:

    B1051’s missions Launch Date (UTC) Turnaround Time (Days)
    SpaceX Demonstration Mission-1 2 March 2019 N/A
    RADARSAT Constellation 12 June 2019 102
    Starlink V1.0 L3 29 January 2020 231
    Starlink V1.0 L6 22 April 2020 84
    Starlink V1.0 L9 7 August 2020 107
    Starlink V1.0 L13 18 October 2020 72
    SXM-7 13 December 2020 56
    Starlink V1.0 L16 20 January 2021 38
    Starlink V1.0 L21 14 March 2021 53
    Starlink V1.0 L27 9 May 2021 56

    This was the first time an orbital class rocket booster flew 10 missions and marked a critical reuse milestone for SpaceX.

    On 30 March 2017, SpaceX reused a Falcon 9 booster for the first time when SES-10 launched from LC-39A at the Kennedy Space Center under the power of core B1021, which a year prior became the first booster to land on SpaceX’s floating platform Of Course I Still Love You.

    B1021 on Of Course I Still Love You after landing (Credit: SpaceX)

    In May 2018, SpaceX debuted an upgraded Block 5 variant of the Falcon 9. This new version was to be capable of carrying crewed missions and take lessons learned from previous blocks to decrease turnaround and refurbishment time; the company set the ambitious goal of reusing a booster 10 times with minimal refurbishment between each flight.

    Since the first flight of Falcon 9 Block 5, SpaceX has transitioned from simply manufacturing Falcon 9 first stages to operating a fleet of reusable rockets. Although the company still manufactures new boosters, they are becoming increasingly rare to see on the launch pad; in fact, not a single new first stage has launched so far in 2021.

    With less demand for first stage boosters, SpaceX’s Hawthorne, California factory now focuses more on producing a large number of second stages to support an ever-increasing launch cadence.

    Over the years, customers have become more and more comfortable flying on reused rockets. The United States Space Force recently allowed key national security missions to fly on used hardware, and even NASA has accepted flown boosters on crewed missions, the first of which launched several weeks ago on the Crew-2 mission.

    In December 2020, Sirius-XM became the first paying customer to use a “high-flight number” booster when the SXM-7 satellite successfully launched on the seventh flight of booster B1051.

    Thanks to their homegrown internet constellation, SpaceX has been able to expand the envelope of recovering and reusing hardware. With an abundance of internal payloads to launch, the company has been able to reduce turnaround times and launch individual boosters more and more without risking paying customers’ payloads.

    This is evident in the number of times a booster has flown before each launch:

    Flight 1 Flight 2 Flight 3 Flight 4 Flight 5 Flight 6 Flight 7 Flight 8 Flight 9 Flight 10
    2017 13 5 0 0 0 0 0 0 0 0
    2018 10 12 1 0 0 0 0 0 0 0
    2019 7 5 4 1 0 0 0 0 0 0
    2020 5 3 4 6 4 2 2 0 0 0
    2021 0 1 0 1 2 3 2 2 2 1

    SpaceX has also drastically reduced the turnaround times in 2021. Before this year, the fastest turnaround of a Falcon 9 was 51 days, between Starlink L11 and Starlink L14 — itself a global record.

    In 2021, SpaceX has so far beaten this record six times, with two turnaround times at just 27 days. The average turnaround time has also decreased by approximately 48% since 2020:

    Year Average Turnaround Time (Days)
    2017 225.2
    2018 224.5
    2019 139.8
    2020 113.8
    2021 59.5

    SpaceX has several more missions in the coming weeks. First is the Starlink V1.0 L26 mission on 15 May at 18:58 EDT / 22:58 UTC. That mission will use B1058-8 and launch from LC-39A. The mission may include two rideshare payloads: the Capella 5 and 6 satellites.

    Falcon 9/Starlink v1.0 L27 UPDATES
  • SpaceX Missions Section
  • L2 SpaceX Section
  • Click here to Join L2
  • Next is SiriusXM’s SXM-8 on 1 June at 00:25 EDT / 04:25 UTC from SLC-40. Two day later, SpaceX will launch the CRS-22 mission on 3 June using booster B1067-1 (the first new core to enter the fleet in 2021) launching from LC-39A.

    The final confirmed upcoming SpaceX mission is GPS-III SV05 on 17 June; it will use B1062-2 and launch from SLC-40.

    The Launch

    Prior to launch, no static fire test was conducted, continuing a trend among SpaceX’s internal Starlink missions to skip the static fire and proceed to launch.

    Since Starlink V1.0 L8, 14 Falcon 9 flights have not required a static fire test due to both the reliability of flight-proven first stage boosters and the majority of those missions being internal Starlink flights.

    For external missions, paying customers can request a static fire before launch.

    Pre-launch countdown:

    T- time to launch Event
    T-38 mins Launch Director confirms “go” for propellant loading
    T-35 mins Fueling begins with RP-1 kerosene to both stages & liquid oxygen to Stage 1 only
    T-17 mins RP-1 kerosene load to Stage 2 complete
    T-16 mins Liquid oxygen load into Stage 2 begins
    T-7 mins First stage Merlin engine chilldown begins
    T-2 mins 30 secs Fueling of the Falcon 9 for launch complete
    T-1min Falcon 9 takes control of countdown & pressurizes its propellant tanks for launch
    T-45 secs Launch Director verifies “go” for launch
    T-3 secs Merlin 1D engine ignition command sent
    T0 Liftoff

    After lifting off, the vehicle performed a pitch and roll maneuver to place itself onto the correct heading and into the proper orientation to achieve a 53 degree orbit of the Earth. Falcon 9 achieved MaxQ 1 minute 12 seconds into flight, followed by staging at T+2 minutes 36 seconds.

    The second stage then ignited as the first stage oriented itself for its 10th reentry and landing.

    Over six minutes into flight, the first stage reignited its center engine, E9, shortly followed by two outer engines, E1 and E5. These three engines contain TEA-TEB canisters, allowing them to be relit in flight, which is different from how the engines are ignited on the ground before liftoff. On the ground, the TEA-TEB is provided by the launch pad’s ground service equipment.

    Shortly after, the first stage then lit E9 again to land on the Just Read the Instructions droneship approximately 615 km downrange.

    This marked the 83rd landing of a Falcon 9 booster and the 21st landing attempt on Just Read the Instructions. The droneship will now take the booster back to Port Canaveral to begin a series of inspections ahead of rejoining the fleet.

    Meanwhile, the second stage continued to haul the Starlink stack into its initial parking orbit.  The payload fairings separated 3 minutes 04 seconds into flight and parachuted into the Atlantic where the Shelia Bordelon was standing by to recover them from the water approximately 680 km downrange of the launch site. 

    As with the first stage, the payload fairing halves on this flight were reused. Both fairing halves previously flew together on the GPS III SV04 mission 185 days ago.

    The second stage and Starlink payload reached their initial parking orbit 8 minutes 47 seconds after launch. The second stage then began to coast for about 37 minutes before settling its propellant and reigniting its Mvac engine for one second. Once the second burn was complete, the Falcon 9 was in a 260 x 280 km orbit. 

    Afterward, the second stage began to spin in preparation for Starlink deployment. The 60 satellites will then deploy from the second stage and drifted apart due to the difference in angular momentum imparted by the spinning rocket stage.

    The 60 satellites will now begin to maneuver to reach their 550 km operational orbits. 

    (Lead image credit: B1051-10 on its 10th launch. Credit: Stephen Marr)

    The post SpaceX flies historic 10th mission of a Falcon 9 as Starlink constellation expands appeared first on NASASpaceFlight.com.

    Source : NASA More   

    This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.