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Post by Jairo on Oct 11, 2005 10:31:16 GMT -4
I read here that the descent engine exit had a diameter of 54in (using the Encyclopaedia Astronautica as reference), but I already knew a PDF scan (Apollo Operations Handbook, LM 10 and subsequent, table 2.3-1) that said it had 63in. Besides that, the Encyclopaedia Astronautica also mentions two different engines ( RS-18 and TR-201) as being the LM ascent engine. Is this a mistake or they really changed the engines from one LM to another? |
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Post by gwiz on Oct 11, 2005 11:00:22 GMT -4
To a certain extent, it depends what you're measuring - internal diameter of actual nozzle v external diameter of nozzle skirt might explain the difference. From a nozzle exit area figure I found, the internal diameter on Apollo 9 was 57 inches. Possibly the later LMs had an extended nozzle.
Rocketdyne built the ascent motor, TRW the descent motor, so it looks as if the encyclopaedia is getting things a bit twisted.
Edit. Have just found the corresponding document for Apollo 10, still 57 ins.
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Bob B.
Bob the Excel Guru?
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Post by Bob B. on Oct 11, 2005 11:05:36 GMT -4
Besides that, the Encyclopaedia Astronautica also mentions two different engines ( RS-18 and TR-201) as being the LM ascent engine. Is this a mistake or they really changed the engines from one LM to another? I'm pretty sure the TR-201 was derived from the original RS-18 LM's descent stage engine. The TR-201 was used on the 2nd stage of the Delta 1000, 2000 & 3000 launch vehicles. As you can see from the astronautix.com page, the TR-201 was first flown in 1974, thus it couldn't have been used on the LM. The RS-18 appears to be the LM's ascent engine (developed in 1967). |
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Post by gwiz on Oct 11, 2005 11:16:28 GMT -4
I don't recall either designation being used at the time. The ascent motor was originally designed by Bell, who called it the 8258. I think TRW called the descent engine something like MIRA 10K.
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Post by JayUtah on Oct 11, 2005 15:18:17 GMT -4
The TR-201 is the LM ascent engine and did serve on some of the Delta second stages. After the TRW engine went out of production, Aerojet built a follow-on product that took its place in the Delta vehicle.
Rocketdyne did not built the DPS. They were contracted, but it was a parallel contract award since the DPS was considered a difficult task. STL's design was eventually chosen and the Rocketdyne contract was canceled.
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