STP-02: DSX + попутчики - Falcon Heavy - Kennedy LC-39A - 25.06.2019, 06:30 UTC

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Ian Atkinson‏ @IanPineapple 34 мин. назад

@SpaceX has updated the droneship FCC filings for STP-2. OCISLY will be stationed approximately 1240km (!!) downrange from KSC. This will be *even further* than Arabsat's center core landing (which was only 967km). The purpose of this change is not known. Keep cool, B1057.

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Stephen Clark‏ @StephenClark1 21 мин. назад

USAF official confirms no ballast, approximate total value of the mission (including spacecraft and launch services) roughly $750 million.

Stephen Clark‏ @StephenClark1 25 мин. назад

Falcon Heavy's 3rd launch, set for takeoff June 24 from the Kennedy Space Center, will carry 24 spacecraft to three distinct orbits over a mission lasting several hours. 3700 kg total mass for the payload stack uses up most of the Falcon Heavy's performance, no ballast on-board.

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Julia [SCLA]‏ @julia_bergeron 47 мин. назад

The worklights are on at 39A. That means there could be a Heavy rolling out to the pad tonight.

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Chris B - NSF‏ @NASASpaceflight 21 мин. назад

Static Fire Window opens at 12:30pm Local Time. Usually runs for six hours.

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06/19/2019 05:23 Stephen Clark

The Falcon Heavy is now emerging from the hangar to begin the trip up the ramp to pad 39A in preparation for a static fire test scheduled tomorrow.

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06/19/2019 13:09 Spaceflight Now

The Falcon Heavy is being raised vertical at launch pad 39A at the Kennedy Space Center in readiness for an engine test fire.

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06/19/2019 13:36 Spaceflight Now

The Falcon Heavy, with its payload fairing attached, stands tall on launch complex 39A as the Sun rises over Kennedy Space Center.

The powerful rocket is scheduled to launch the U.S. Air Force's Space Test Program-2 mission no earlier than June 24 with a cluster of military and scientific research satellites.

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Julia [SCLA]‏ @julia_bergeron 1 ч. назад

The first @SpaceX Falcon Heavy with flight proven side boosters is vertical at historic LC-39 A. Full stack static fire is expected today ahead of the #STP2 launch scheduled for NET 6/24.

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Ken Kremer‏ @ken_kremer 1 ч. назад

The full #FalconHeavy with payload fairing attached stands vertical at #pad39A this morning after rollout at 1 AM and raising at 6 AM - ahead of static fire NET this afternoon. @SpaceX #STP2 launch NET Jun 24. Note: Sooty flight proven side cores recycled from #arabsat6a

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Полигон открыт для предпусковых и пусковых операций

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Опубликована

Airspace Closure Area

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Объявлена

Launch Hazard Area

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Chris B - NSF‏ @NASASpaceflight 5 мин. назад

SpaceX Falcon Heavy Static Fire now moved to 8:30 pm local time. If you're there watching and getting bitten by bugs, seek shelter, this isn't happening for hours yet.

NET 00:30 UTC 20.06.2019

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https://www.teslarati.com/spacex-surprise-falcon-heavy-booster-landing-distance-record/

A SpaceX surprise: Falcon Heavy booster landing to smash distance record

FALCON HEAVY CENTER CORE B1055 LANDED ABOARD DRONE SHIP OCISLY NEARLY 970 KM (600 MI) OFF THE COAST OF FLORIDA. CENTER CORE B1057 COULD SMASH THAT RECORD BY ALMOST 30% ON JUNE 24TH. (SPACEX)

 By Eric Ralph
Posted on June 19, 2019

In an unexpected last-second change, SpaceX has moved Falcon Heavy Flight 3's center core landing on drone ship Of Course I Still Love You (OCISLY) from 40 km to more than 1240 km (770 mi) off the coast of Florida.

Drone ship OCISLY is already being towed to the landing site, necessary due to the sheer distance that needs to be covered at a leisurely towing pace. The current record for distance traveled during booster recovery was set at ~970 km by Falcon Heavy center core B1055 in April 2019. If successful, Falcon Heavy center core B1057 will smash that record by almost 30% after sending two dozen spacecraft on their way to orbit. Falcon Heavy Flight 3 is scheduled to lift off in support of the Department of Defense's Space Test Program 2 (STP-2) mission no earlier than 11:30 pm ET (03:30 UTC), June 24th. A routine static fire test at Pad 39A will (hopefully) set the stage for launch on Wednesday, June 19th.

https://twitter.com/ChrisG_NSF/status/1141099086499799040

This comes as a significant surprise for several reasons. First and foremost, the difference between a center core landing 40 km or 1300 km from the launch site is immense. For Falcon Heavy, the center core shuts down and separates from the rest of the rocket as much as a minute after the rocket's two side boosters, potentially doubling the booster's relative velocity at separation.


A return to launch site (RTLS) booster recovery requires a ton of latent performance, particularly for a booster traveling as fast as a Falcon Heavy center core. (USAF – James Rainier)

That extra minute of acceleration means that the center core can easily be 50-100+ km downrange at the point of separation. In other words, landing 40 km offshore aboard drone ship OCISLY would be roughly akin to a full boostback burn, meaning that the center core would need to nullify all of its substantial downrange velocity, turn around, and fly ~50-100 km back towards the launch site. Being able to perform such an aggressive maneuver would indicate that Falcon Heavy's boost stage has a huge amount of propellant (delta V) remaining after completing its role in the launch. 

To have STP-2's center core recovery moved from 40 km to 1240 km thus indicates an absolutely massive change in the rocket's mission plan and launch trajectory. For reference, Falcon Heavy Flight 2's Block 5 center core (B1055) set SpaceX's current record for recovery distance (970 km/600 mi) after launching Arabsat 6A – a massive ~6500 kg (14,300 lb) satellite – to a spectacularly high transfer orbit of >90,000 km (56,000 mi).

https://twitter.com/StephenClark1/status/1141145678627971074

WHY SO SPICY?

There are three obvious possibilities that might help explain why the STP-2 mission has abruptly indicated that it will require SpaceX's most energetic booster recovery yet.

1. STP-2 IS CARRYING AT LEAST 1-2 METRIC TONS WORTH OF MYSTERY PAYLOAD(S)

This is highly unlikely. The USAF SMC has already released a SpaceX photo showing the late stages of the STP-2 payload stack's encapsulation inside Falcon Heavy's payload fairing. Short of an elaborate faked encapsulation followed by the installation of additional mysterious spacecraft or some extremely dense hardware hidden inside, it's safe to say that the STP-2 payload stack weighs what the USAF says it weighs, which is to say not nearly heavy enough to warrant a record-smashing booster recovery given the known orbital destinations.

https://twitter.com/AF_SMC/status/1141099481628364808

The USAF further confirmed that there is no ballast on the stack, removing the possibility of a lead weight or steel boilerplate meant to artificially push Falcon Heavy to its limits.

2. STP-2'S ALREADY-CHALLENGING FALCON UPPER STAGE MISSION PROFILE IS EVEN MORE EXOTIC THAN DESCRIBED

Per official mission overviews, it's already clear that STP-2 could be the most challenging launch ever attempted for SpaceX's orbital Falcon upper stage. According to SpaceX itself, "STP-2...will be among the most challenging launches in SpaceX history, with four separate upper-stage engine burns, three separate deployment orbits, a final propulsive passivation maneuver, and a total mission duration of over six hours."


An overview of the STP-2 Falcon Heavy upper stage's exotic and extremely challenging mission profile. (USAF)

While undeniably challenging, it's not clear why it would require such a high-energy center core recovery. With a payload mass of just ~3700 kg, Falcon 9 has launched much larger payloads to (relatively) higher orbits, but this fails to account for the added challenge of long coasts and multiple different orbits. Also of note, the above graph (courtesy of a years-old USAF document) appears to disagree with SpaceX's description of "four... upper-stage burns", instead showing five burns (red spikes). 

More likely than not, OCISLY's ~1200-kilometer move can be explained largely by the reintroduction of what the above graph describes as the Falcon upper stage's "disposal burn", likely referring to a deorbit burn. On top of the delta V already required for the first four burns, it isn't out of the question that an additional coast and deorbit burn from 6000 km (3700 mi) would push the recovery equation in favor of attempting to incinerate center core B1057.

Falcon Heavy's upper stage deploys its payload fairing, revealing the STP-2 payload stack. (SpaceX)

3. USAF/DOD CONSERVATISM STRIKES AGAIN?

The last plausible explanation for this radical shift is that the US Air Force/Department of Defense (DoD) has decided last-second that they want more margins on top of their already-overflowing safety margins, quite literally pushing B1057 to the edge of its performance envelope to mitigate low-probability failure modes. This has been done to an even more extreme extent with the US Air Force's recent GPS III SV01 launch, in which SpaceX was forced to expend a new Falcon 9 Block 5 booster to provide the extreme safety margins the USAF desired.

According to the USAF, the STP-2 mission – including launch costs – represents as much as $750M, coincidentally similar to the estimated cost of the GPS III SV01 satellite and an expendable Falcon 9 rocket. As such, it's not out of the question that a similar level of paranoia/conservatism is in play for STP-2.


Falcon 9 lifts off with the US Air Force's first ~$500M GPS III spacecraft, December 2018. (SpaceX)

Numbers 2 and 3 are equally plausible explanations for this last-second booster recovery shift. Given the US military's active involvement, it's more likely than not that no explanations will be offered. Regardless, this surprise development is bound to result in a truly spectacular recovery attempt for SpaceX's second Block 5 center core and will likely involve breaking several still-fresh records in the process. 

Falcon Heavy Flight 3 is in the middle of rolling out to SpaceX's Kennedy Space Center Pad 39A launch facilities for a routine pre-launch static fire test, scheduled to occur no earlier than 12:30 pm ET (16:30 UTC), June 19th. If all goes well, SpaceX should be on track for its first STP-2 launch attempt at 11:30 pm ET (03:30 UTC), June 24th.

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06/19/2019 22:31 Stephen Clark

The Falcon Heavy static fire test is currently scheduled some time during a window between 6 p.m. and 12 a.m. EDT (2200-0400 GMT).

The rocket has a payload fairing attached, but the shroud mounted on top of the Falcon Heavy for today's hotfire test does not contain the payloads set for launch next week.

The fairing is a "non-flight" component, and was added for the static fire at the request of the Air Force to collect acoustic data. The fairing containing the 24 spacecraft set for launch next week will be installed on the Falcon Heavy once it rolls back to SpaceX's hangar after the test-firing.

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Julia [SCLA]‏ @julia_bergeron 58 сек. назад

39-A is about to get drenched. Hold on out there KSC folks!

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Штормило...

Kyle Gravlin‏Подлинная учетная запись @kylegravlin 8 мин. назад

Here's a look at the map. Stay with @WESH 2 for the latest...

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NOTMAR (локальный)

lnm07252019.pdf, стр 5

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Chris B - NSF‏ @NASASpaceflight 2 мин. назад

SpaceX Falcon Heavy Static Fire test at 39A is heading towards a T-0 of sometime around midnight local time.

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06/20/2019 02:03 Spaceflight Now

Thunderstorms have battered the Kennedy Space Center today as SpaceX prepared for a pre-launch engine test firing for its Falcon Heavy rocket.

The NASA launch site and adjacent Cape Canaveral Air Force Station are currently under a Phase 2 lightning advisory.