Author
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Topic: Apollo Block I spacecraft lifespan on orbit
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Jim_Voce Member Posts: 273 From: Registered: Jul 2016
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posted 07-11-2018 01:29 AM
In 1962, when the Space Task Group was developing the earliest version of the Apollo command and service module, it was envisioned that the CSM would fly solo missions in Earth orbit for up to 14 days, so this became the primary objective of the Apollo 1 mission.Does anyone know what the maximum life support duration was of the Block I Apollo CSM past 14 days? Was it 21 days? |
oly Member Posts: 971 From: Perth, Western Australia Registered: Apr 2015
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posted 07-11-2018 06:16 AM
quote: Originally posted by Jim_Voce: ...for up to 14 days, so this became the primary objective of the Apollo 1 mission.
What reference are you using for this information? |
oly Member Posts: 971 From: Perth, Western Australia Registered: Apr 2015
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posted 07-12-2018 02:30 AM
The specification requirements for the Apollo Command and Service Module Environmental Control Systems required a duration of 14 days. To meet this, 78.29 kg (172.6 lb] of oxygen supply was specified, along with additional consumables like water, power etc.As the Gemini spacecraft tested longer duration spaceflight, and systems such as fuel cells were tested and improved, the Apollo consumables were streamlined. The oxygen supply was designed to cater for three astronauts, included crew consumption, cabin leakage, cabin repressurizations, LM support, one CM puncture, tank bleeds, cabin and WMS purges and EVA flow. Additional water was generated as a by-product of power generation from fuel cells, and most missions ended with more than they began with. So up until the first flight of Apollo 7, mission duration was an unconfirmed number, and following the first mission, was an ever-improving number. Duration depended upon crew activity and oxygen usage. Carbon dioxide scrubber endurance was made available for the designed duration of the available life support, and fuel supply was dependent on mission usage. No mission was planned beyond the duration of the Environmental Control System (life support) for obvious reasons. When you state that the "CSM would fly solo missions in Earth orbit for up to 14 days, so this became the primary objective of the Apollo 1 mission," this statement is incorrect for 1962. The specifications were drawn up and systems needed to be designed and built to meet these specifications. Skylab proved that the CSM could stay on orbit for longer than 14 days. This document references the systems specifications and requirements. |
Blackarrow Member Posts: 3160 From: Belfast, United Kingdom Registered: Feb 2002
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posted 07-12-2018 08:15 AM
quote: Originally posted by oly: Skylab proved that the CSM could stay on orbit for longer than 14 days...
I assume the Skylab CSMs were powered down to allow for missions up to (and possibly beyond) 84 days. On Apollo 13, the CSM was famously "switched off" to save power. My understanding is that the CSM was not designed to be switched off, and there were (unfounded) concerns about powering the CSM up again (if only because of short-circuits from condensation getting into the electrical contacts). How did the powering down of the Skylab CSMs differ from what happened on Apollo 13? |
SpaceAholic Member Posts: 4494 From: Sierra Vista, Arizona Registered: Nov 1999
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posted 07-12-2018 12:34 PM
The CSM was not completely powered down — some critical subsystems remained energized drawing power through an umbilical connected to Sklyab's MDA (multiple docking adapter). |
oly Member Posts: 971 From: Perth, Western Australia Registered: Apr 2015
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posted 07-13-2018 07:27 AM
For me, this took a little research, and someone here may know more detail.The Skylab Service Module had one of the fuel cells removed and additional batteries installed. The Skylab Command Module flight plan identified that the fuel cells are shut down as the Hydrogen fuel supply was depleted, which occurred 19 days after lift-off for Skylab 4, and the CSM was placed in quiescent mode. After shutdown, the hydrogen vent was opened and the small amount of residual hydrogen was vented overboard through the nonpropulsive vent. The remaining oxygen was managed by flowing oxygen through the polychoke orifice into the command module. Power could be transferred to and from the Command module and Skylab, the additional batteries were used to power the CSM from undocking through to re-entry. I am trying to locate a better copy of the flight manual and flight plan to find additional details |
Space Cadet Carl Member Posts: 225 From: Lake Orion, Michigan Registered: Feb 2006
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posted 07-14-2018 09:14 AM
I just learned the Skylab command modules were painted white instead of using silver Kapton foil. After all these years, I'm still finding stuff out! |
oly Member Posts: 971 From: Perth, Western Australia Registered: Apr 2015
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posted 07-14-2018 09:39 AM
There are many interesting facts about the Skylab project, such as this: Skylab space station airlock module: Gemini hatch. |