SES 8 - Falcon 9 v1.1 - 03.12.2013 - Canaveral SLC-40

[Salo]

http://www.aviationweek.com/Article/PrintArticle.aspx?id=/article-xml/AW_10_07_2013_p26-623326.xml&p=1&printView=true

New Falcon 9 Falls Short On Stage Functions

By Guy Norris, Amy Svitak
Source: Aviation Week & Space Technology

October 07, 2013
Credit: SpaceX

SpaceX engineers will have some changes to make on the company's new Falcon 9 v1.1 launch vehicle before its next mission, following lessons learned from its Sept. 29 demonstration flight.
A preliminary test of an innovative reusable-booster concept intended to hold down costs showed the need for more work after an uncontrollable spin apparently hampered pre-spashdown braking. The vehicle also aborted a planned restart of its upper-stage engine during the otherwise successful debut of the upgraded rocket.
With more than $1 billion in commercial-launch backlog, restarting the Merlin 1D vacuum engine that powers Falcon 9's upper stage is critical to delivering government and commercial satellite payloads to geostationary transfer orbit (GTO), the destination of most commercial telecom spacecraft. But SpaceX CEO/Chief Technology Officer Elon Musk downplayed the upper-stage restart, characterizing it as an "optional" part of the flight profile.
"We essentially saw the engine initiate ignition, get up to about 400 psi, and then it encountered a condition it didn't like, and we think it may have been due to an extended spin start—maybe, this is speculative—and so it initiated an abort of the restart," Musk said post-launch. "We have all the data from the restart, so I'm confident we'll be able to sort it out and address it before the next flight."
That mission is expected to loft the new rocket's first GTO mission—the SES-8 telecommunications satellite for fleet operator SES—late this month.

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Longer term, SpaceX wants to reuse hardware to hold down costs. The Falcon 9 v1.1 flight included an attempt to slow the hypersonic first stage for a controllable descent to the Pacific Ocean. Before launch, Musk gave this only a slim chance of working on the demo flight, but it seems it was at least partially successful.
Following main-engine cutoff, burnout and separation, with the stage likely slowing well below Mach 10, three of its nine engines were intended to fire to decelerate the booster for its initial descent. A single engine was then due to fire to perform a final braking maneuver just before the stage impacted the ocean at a slow, landing-like speed.
While the initial high-altitude retrofire sequence appeared to work to plan, Musk said the stage "actually ended up spinning to a degree that was greater than we could control with the gas thrusters, and it centrifuged the propellant. It caused the boost stage to run out of propellant before hitting the water. So it hit the water relatively hard."
The stage lacked the landing gear that Musk says would help stabilize a reusable unit. SpaceX's reusability plan builds on a vertical landing and recovery system that has undergone initial tests at the company's facility in McGregor, Texas, using the Grasshopper demonstrator. Although only a foreshortened Merlin 1D-powered first stage, the Grasshopper's precise maneuvers and landings have bolstered confidence in the concept.
"Between this flight and Grasshopper tests, we now have all the pieces of the puzzle to bring the rocket back home," said Musk. "If things go super well, then we will be able to re-fly a Falcon 9 stage before the end of next year."
SpaceX plans to test a larger version of the Grasshopper, also dubbed the Falcon 9R (reusable)—with nine -1Ds more representative of the upgraded production launch vehicle—at a specially constructed site at Spaceport America in New Mexico.
As for the upper-stage abort, Musk said the Merlin 1D has been successfully reignited "dozens of times" during ground tests, but he conceded the company still needs to address minor technical issues associated with operating the engine in the vacuum of space.
"We just need to iron out the differences between restarting in vacuum and in microgravity versus restarting on the ground," he noted. The issue could delay the launch of the SES-8 satellite by "a few extra weeks, to make sure we're super-confident of the second-stage restart," he added.
Musk said the Falcon launch vehicle that will loft SES-8 is at SpaceX's Cape Canaveral AFS launch facility.
"We're ready to go with SES, with a steady cadence of launches thereafter," he said, which would include the Thaicom 6 anticipated later this year, followed by SpaceX's third cargo resupply mission to the International Space Station (ISS) in February.
SES is discussing the reignition abort with SpaceX, and at press time it had not yet shipped the Orbital Sciences Corp.-built spacecraft to the Cape, which ceased operations last week with the U.S. government shutdown.
Beyond reusability and upper-stage reignition, there were several other key milestones for the upgraded Falcon 9. It successfully delivered the first of six payloads into orbit 14 min. after it left the pad. These included the Canadian-built CAScade, Smallsat and IOnospheric Polar Explorer (Cassiope) satellite, Canada's first space environment sensor suite.
Major modifications to the new Falcon include the more powerful Merlin 1D engines, arranged for the first time in an "Octaweb" pattern with a central engine surrounded by eight other engines, rather than the former 3 X 3 configuration of previous Falcons. The Octaweb thrust structure also supports the higher thrust of the Merlin 1D, each of which develops 147,000 lb. thrust at sea level, rising to 161,000 lb. at altitude. Total thrust at launch is 1.3 million lb., increasing to 1.5 million lb. in vacuum.
Each kerosene-fueled engine is fed via a single-shaft, dual-impeller turbopump. The fuel is also cycled to provide regenerative cooling of the thrust chamber and expansion nozzle, as well as serving as the pressurized fluid to control the thrust vector actuators.
The 227-ft. vehicle incorporates extended fuel tanks as well as improved avionics and a larger, 43 X 17-ft.-dia. payload fairing. The demo was the first SpaceX flight from space launch complex SLC-4E, a former Titan 4 pad the company is leasing from the Air Force.
Aside from the faster-than-hoped-for splashdown of the first stage, the flight was not without its share of drama. Reports based on information from SpaceTrack, a satellite tracking and space situational awareness service, indicated a larger-than-expected debris field in the orbital path of the vehicle, with up to 20 discrete objects in view. The tracking data led to speculation that the second stage may have disintegrated shortly after payload deployment.
"We have no reason to believe there was an explosion of any kind," SpaceX declared, noting that following insertion of the satellites to the correct orbit, "the Falcon 9 second stage underwent a controlled venting of propellants and the stage was successfully safed. During this process, it is possible insulation came off the fuel dome on the second stage, and is the source of what some observers incorrectly interpreted as a rupture in the second stage."
The company adds that it "will continue to review to help identify the source of the extra debris, but our data confirms there was no rupture of any kind on the second stage."

[свернуть]

[igorvs]

Старт передвинулся на 12 ноября
http://forum.nasaspaceflight.com/index.php?topic=32783.0

[igorvs]

http://www.nasaspaceflight.com/2013/10/spacex-realign-falcon-9-missions/

[Salo]

The company's Falcon 9 v1.1 is now set to launch with the SES-8 spacecraft no sooner than November 12

Не ранее 12 ноября.
В случае задержек возникнет конфликт с MAVEN и пуск уйдёт на конец ноября..

[igorvs]

Первое фото нового подъемника во Флориде
https://twitter.com/LH2Padrat/status/391327151813058560/photo/1

[Salo]

[Ну-и-ну]

Это первый подъём нового (4-го вроде? - первые два оказались одноразовыми) подъёмника. За месяц до пуска.

Вообще, парадокс - путь к многоразовой ракете лежит через одноразовые подъёмники.

[cavia]

Чем вызвана их одноразовость? откуда информация?

[Ну-и-ну]

Информация от сравнения фотографий глазами. Проделывали сие на НСФ.

[Старый]

А одноразовость наверно от того что после попадания на это факела двигателя для второго раза оно уже не годилось?

[cavia]

мне кажется, что это процесс постоянной модификации, так как похоже всё делается в адской спешке и авралах.

[Ну-и-ну]

22 ноября.

[Salo]

http://forum.nasaspaceflight.com/index.php?topic=32783.msg1112129#msg1112129

Ben the Space Brit пишет:
I'm asking because if the U/S is already on site, then the hardware portion of the restart fix, whatever it is, is already done. If the U/S is either at Hawthorne or MacGreggor then it's still being tested.

Antares пишет:
Disagree.  Rockets can be altered in the field.  Fixes don't need to be tested on the vehicle if it can be tested on other articles in flow or previous test assets.

Lurker Steve пишет:
I guess it depends on what the fix is, and how much assembly / disassembly is needed.
If they can test the fix on the ground, they will test a different stage first, then apply those changes to the SES-8 second stage. It's always easier to do things in the factory when you have all of the required tools and fixtures handy.

padrat пишет:
Second stage is on site. And yes, fix is being implemented

[Salo]

http://www.nasaspaceflight.com/2013/10/spacex-press-abort-test-raptor-engine/

SpaceX Status: Most of SpaceX's current focus is on the upcoming salvo of missions, with the second launch of their upgraded Falcon 9 v1.1 aiming to follow up the success of the Cassiope mission.

 The launch vehicle – and its passenger, the SES-8 satellite – are both undergoing launch processing at SpaceX's SLC-40 complex. However, the launch date has since slipped to a NET (No Earlier Than) November 22 launch date, per L2′s SpaceX section.
Efforts into the Upper Stage re-start investigation are ongoing, following its issue during the Cassiope mission. While the Canadian satellite was successfully deployed, a re-start of the stage was attempted as part of SpaceX's fully-reusable launch vehicle aspirations.
The relevance to the SES-8 mission is the requirement to re-start the upper stage as part of the satellite's mission profile. It is understood the stage re-starts without issue during ground testing, but may have a unique issue once in the cold vacuum of space.
With the delay to the SES-8 mission, the prospect of the next flight of the F9 v1.1 – carrying the Thaicom-6 satellite – occurring just one month later are all-but gone.
A separation of 30 days between launches is understood to be a hard limit, resulting in the Thaicom-6 mission having to avoid the holiday period and re-target for a launch in the new year.
All launch dates are subject to change, with the realigned target of November 22 for SES-8 a preliminary placeholder, subject to approval from the Eastern Range. Should approval be granted, the launch window will stretch from 13:28 to 15:28 local time, per L2.

[ВВК]

Salo пишет:

http://www.nasaspaceflight.com/2013/10/spacex-press-abort-test-raptor-engine/
Цитата

Спойлер

...Efforts into the Upper Stage re-start investigation are ongoing, following its issue during the Cassiope mission....

[свернуть]

Т.е. они все-таки не определились что произошло

[Salo]

Что бы это значило?
http://www.ses.com/4233127/upcoming-launches

[Salo]

Уходит на 2014?

[Александр Ч.]

ХЗ, ибо тут http://www.ses.com/4629034/ses-8 по прежнему написано: Launch date 2013, Q4
Кстати, для Astra-2G и SES-9 носитель нен указан.

У Орбитала http://www.orbital.com/SatellitesSpace/Communications/SES-8/ тоже без изменений: "Status: In Integration and Test. Scheduled for Launch in 2013"

[anik]

Salo пишет:
Что бы это значило?
 

Это значит, что событие имело период отображения на сайте только до 31 октября включительно, а когда наступило 1 ноября, то оно исчезло. Ничего страшного - поправят дату, и событие снова появится. Конкретно у SES это уже не в первый раз такое происходит.

[Salo]

Спасибо!