Is there any way to guess the Isp & thrust benefits on the kerolox M1D?cheers, Martin
(snip)How much thrust does the M1C tubo-pump exhaust produce? A couple thousand lbs? How much is needed for roll control on the second stage? A couple hundred? (snip)S
Quote from: Hooperball on 10/06/2012 06:19 pm(snip)How much thrust does the M1C tubo-pump exhaust produce? A couple thousand lbs? How much is needed for roll control on the second stage? A couple hundred? (snip)SDurring the second stage burn on yesterday's CRS-1 launch, the roll control seemed to be activated at about seven second intervals. This was much more frequent, many more times, than on the three previous flights. It would be interesting to see if this effects the implimentation of M1-D vac and second stage roll control.
Has anyone heard the number of starts that can be done by the Vacuum version of the Merlin 1D?
Quote from: Comga on 10/11/2012 03:02 amHas anyone heard the number of starts that can be done by the Vacuum version of the Merlin 1D?The max capability other than the obvious of 2 is not known but a value of 3 has been speculated based on being able to do some missions that would need 3 burns.
Quote from: oldAtlas_Eguy on 10/18/2012 06:32 pmQuote from: Comga on 10/11/2012 03:02 amHas anyone heard the number of starts that can be done by the Vacuum version of the Merlin 1D?The max capability other than the obvious of 2 is not known but a value of 3 has been speculated based on being able to do some missions that would need 3 burns.I forget where I heard it, but I remember either reading or hearing from a friend who interned at SpaceX that they can restart regular Merlins up to 6-7 times.
Quote from: mlindner on 10/29/2012 01:26 pmQuote from: oldAtlas_Eguy on 10/18/2012 06:32 pmQuote from: Comga on 10/11/2012 03:02 amHas anyone heard the number of starts that can be done by the Vacuum version of the Merlin 1D?The max capability other than the obvious of 2 is not known but a value of 3 has been speculated based on being able to do some missions that would need 3 burns.I forget where I heard it, but I remember either reading or hearing from a friend who interned at SpaceX that they can restart regular Merlins up to 6-7 times.Does that perhaps mean they can be ground started 6-7 times during their lifetime, including tests at McGregor?M1C doesn't restart at all, and I don't think we've heard a number that high for Merlin Vac, either??cheers, Martin
Side question: what deteriorates between engine restarts? And how hard is to reset it to original conditions if they start reusing them?
Quote from: IRobot on 10/29/2012 11:44 pmSide question: what deteriorates between engine restarts? And how hard is to reset it to original conditions if they start reusing them?They already reuse them. They fire each engine at least three times before launch.Merlin 1D is made for greater reuse.
What capability of an engine is required for several restarts in one flight? What is required to reset that ability to max before launch after several test burns have been done?
Quote from: guckyfan on 10/30/2012 06:28 amWhat capability of an engine is required for several restarts in one flight? What is required to reset that ability to max before launch after several test burns have been done?Ignition charges.