Author Topic: SpaceX Falcon 9 : CRS-12 : Aug 14, 2017 : DISCUSSION  (Read 71564 times)

Offline deruch

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Re: SpaceX Falcon 9 : CRS-12 : Aug 14, 2017 : DISCUSSION
« Reply #240 on: 08/23/2017 12:34 AM »
Just to provide another potential option:

Since they have 9 engines on the first stage, they could have run 1 (or more?) at the higher thrust and used lower thrust on the remaining to end up with the same overall vehicle thrust.  Doing this would allow them an excellent chance to analyze the performance of the uprated engines in comparison to past engines in a range of performances (i.e. higher, equal, and lower thrust).  Would be especially nice as they get the engines back for hands-on study post flight.

I'm not saying that this was done.  Only that it is a scenario that is also compatible with available data.
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline OneSpeed

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Re: SpaceX Falcon 9 : CRS-12 : Aug 14, 2017 : DISCUSSION
« Reply #241 on: 08/23/2017 04:00 AM »
... Since they have 9 engines on the first stage, they could have run 1 (or more?) at the higher thrust and used lower thrust on the remaining to end up with the same overall vehicle thrust.  Doing this would allow them an excellent chance to analyze the performance of the uprated engines in comparison to past engines in a range of performances (i.e. higher, equal, and lower thrust).  Would be especially nice as they get the engines back for hands-on study post flight.

I'm not saying that this was done.  Only that it is a scenario that is also compatible with available data.

Another option is higher throttle after staging, which presents less risk to the primary mission. E.g. For the CRS-11 boostback burn ( http://forum.nasaspaceflight.com/index.php?topic=42389.msg1686855#msg1686855 ) ascent was at 91% of Block 5 thrust, and boostback at 97.5%. CRS-12 however, appears to have used 91% and 90% respectively.

Offline pb2000

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First reused one to return twice... nice going SpaceX
I think you may have your Dragons mixed up :)
« Last Edit: 09/18/2017 12:02 AM by pb2000 »
Launches attended: Worldview-4 (Atlas V 401), Iridium NEXT Flight 1 (Falcon 9 FT)

Offline Shanuson

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Re: SpaceX Falcon 9 : CRS-12 : Aug 14, 2017 : DISCUSSION
« Reply #243 on: 09/22/2017 11:11 AM »
Does anyone know if the mice from RodentResearch-9 survived the return in Dragon as planed?
Also was on any previous missions anything living returned successfully? 

Online gongora

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Re: SpaceX Falcon 9 : CRS-12 : Aug 14, 2017 : DISCUSSION
« Reply #244 on: 09/22/2017 01:59 PM »
In the past experiments they were not returned alive, but for this experiment they were supposed to return alive:

[NASA] Rodent Research-9 (SpaceX-12)
Quote
The Rodent Research-9 mission, RR-9, is the first in a series of rodent payloads on International Space Station (ISS) that is dedicated to NASA-sponsored science experiments.  The previous rodent payloads on the ISS involved commercial and other government agency experiments selected by the Center for Advancement of Science in Space (CASIS).

The spaceflight environment is known to result in significant physiological changes on many aspects of the body during long-duration mission in low Earth orbit, posing hazards to the astronauts.  This missionís primary objective is to use mice to better understand the visual impairment and joint tissue degradation that are affecting astronauts living in space for long periods of time, and to examine possible ways to counteract those health problems.  NASA is also working to maximize science return from this mission by sharing tissues from the animals with as many NASA investigators as possible.

The RR-9 payload consists of three NASA Space Biology investigations that will address the effects of microgravity on a range of different tissues.   One investigation will study the effects of long duration spaceflight on fluid shifts and increased fluid pressures that occur in the head.   These elevated pressures inside the head are believed to be the primary cause of visual impairment in astronauts who undergo long duration spaceflight.  A second investigation will study the impact of spaceflight on the vessels that supply blood to the eyes. The third investigation will study the extent of knee and hip joint degradation due to prolonged exposure to weightlessness.  All the results from the RR-9 experiments will play a role in answering pertinent questions to human space exploration.  Here on Earth, these studies will help us gain more insight into disorders of the eyes, and also the progression of damage in the hip and knee joints of wheel-chair bound patients.   

For the RR-9 mission, live mice will be launched on the SpX-12 Dragon capsule and transferred to their Rodent Habitat upon arrival to the ISS, where they will be maintained in microgravity for the mission duration.  During this time, there will be daily health checks to ensure the animalís health and welfare.  At the end of the mission, the mice will be transferred back into the Dragon capsule and brought back alive to Earth.  After the Dragon capsule splashes down in the Pacific Ocean, the animals will be removed from the capsule and transported to a nearby investigatorís research facility Ė proximity is important to ensure the mice have minimal exposure to 1g after splashdown before they are analyzed by the scientists.  Upon receipt of the animals, the investigators will complete their experiments and collect tissues that can be shared with other scientists.     
« Last Edit: 09/22/2017 01:59 PM by gongora »

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