Quote from: MickQ on 09/28/2010 01:06 amQuote from: alexterrell on 09/27/2010 12:27 pmQuote from: MickQ on 09/22/2010 06:48 amI have been thinking for some time that a major impact event in Mars younger days may have been responsible for a lot of things. Imagine an asteroid striking the planet at what is now the Hellas Basin. This pushed the core of the planet so hard that it bulged out the other side creating Tharsis and the big volcanoes. Phobos and Diemos couold be ejecta fron this event. This could also account for Mars elongated orbit.Anyone Mick.Given the decay in their orbits, one would surmise that the impact was fairly recent (~100 million yrs?) and not early solar system. To create the Tharsis bulge would have been like making Earth's moon.If Phobos is from Mars, it may have less water and hydrocarbons. However, it could be a composite body - it really does a need a manned visit.Alex. I agree. Phobos should be a priority target. I think it was Kkattula who recently posted that it is essentially a NEO with a great view. A perfect place for an outpost to conduct teleoperated research of Mars as well.Mick.And:- It can be reached every 2.2 years. NEOs with low delta V will have infrequent access opportunities.- With Mars / Earth aero capture, delta V requirements are low - about 1.2km/s from Earth Moon L1- A SDHLV (e.g. Jupiter 246) with SEP transfer stage can put 50 tons on Phobos.A couple of months ago I became a fan of "Phobos Direct". Ignore Mars and set up a permanent, substantial base on Phobos. Four SEP cargo flights per year deliver 200 tons of supplies every year. Once the base is up, with ISRU and fuel production, exploring, and then settling Mars is "relatively" easy.
Quote from: alexterrell on 09/27/2010 12:27 pmQuote from: MickQ on 09/22/2010 06:48 amI have been thinking for some time that a major impact event in Mars younger days may have been responsible for a lot of things. Imagine an asteroid striking the planet at what is now the Hellas Basin. This pushed the core of the planet so hard that it bulged out the other side creating Tharsis and the big volcanoes. Phobos and Diemos couold be ejecta fron this event. This could also account for Mars elongated orbit.Anyone Mick.Given the decay in their orbits, one would surmise that the impact was fairly recent (~100 million yrs?) and not early solar system. To create the Tharsis bulge would have been like making Earth's moon.If Phobos is from Mars, it may have less water and hydrocarbons. However, it could be a composite body - it really does a need a manned visit.Alex. I agree. Phobos should be a priority target. I think it was Kkattula who recently posted that it is essentially a NEO with a great view. A perfect place for an outpost to conduct teleoperated research of Mars as well.Mick.
Quote from: MickQ on 09/22/2010 06:48 amI have been thinking for some time that a major impact event in Mars younger days may have been responsible for a lot of things. Imagine an asteroid striking the planet at what is now the Hellas Basin. This pushed the core of the planet so hard that it bulged out the other side creating Tharsis and the big volcanoes. Phobos and Diemos couold be ejecta fron this event. This could also account for Mars elongated orbit.Anyone Mick.Given the decay in their orbits, one would surmise that the impact was fairly recent (~100 million yrs?) and not early solar system. To create the Tharsis bulge would have been like making Earth's moon.If Phobos is from Mars, it may have less water and hydrocarbons. However, it could be a composite body - it really does a need a manned visit.
I have been thinking for some time that a major impact event in Mars younger days may have been responsible for a lot of things. Imagine an asteroid striking the planet at what is now the Hellas Basin. This pushed the core of the planet so hard that it bulged out the other side creating Tharsis and the big volcanoes. Phobos and Diemos couold be ejecta fron this event. This could also account for Mars elongated orbit.Anyone Mick.
Is "Phobos Direct" an actual mission study/proposal or just an idea ?Mick.
Quote from: MickQ on 10/07/2010 05:34 amIs "Phobos Direct" an actual mission study/proposal or just an idea ?Mick.Sadly just an idea - unless I consider my notes and spreadsheets a mission study
I finally found the HEFT study everyone is referring to. Not sure if it's in nasaspaceflight but I found it here in case I'm not the last to read it:http://www.scribd.com/doc/37170377/NASA-future-missions-study-Heft-2
I think it could be adapted to Phobos. The issue I have with NEO missions is they are unique, visit once affairs. That makes them pretty much flags and footprints. Phobos or Deimos is a destination that can be visited every 2.2 years, so long duration infrastructure can be built up with SEP delivered modules.
Quote from: alexterrell on 09/30/2010 09:32 amI finally found the HEFT study everyone is referring to. Not sure if it's in nasaspaceflight but I found it here in case I'm not the last to read it:http://www.scribd.com/doc/37170377/NASA-future-missions-study-Heft-2Thank you for actually posting the link!
Quote from: Warren Platts on 10/08/2010 07:47 amQuote from: alexterrell on 09/30/2010 09:32 amI finally found the HEFT study everyone is referring to. Not sure if it's in nasaspaceflight but I found it here in case I'm not the last to read it:http://www.scribd.com/doc/37170377/NASA-future-missions-study-Heft-2Thank you for actually posting the link!pdf at:http://nasawatch.com/archives/2010/09/human-explorati.html -Alex
Quote from: alexterrell on 10/07/2010 09:56 amQuote from: MickQ on 10/07/2010 05:34 amIs "Phobos Direct" an actual mission study/proposal or just an idea ?Mick.Sadly just an idea - unless I consider my notes and spreadsheets a mission study You have to start somewhere. Care to share what you've done Mick.
Quote from: Robotbeat on 09/07/2010 08:39 pmI agree that astronauts can probably adapt to ~5-10rpm, which should be good enough for Mars-level gravity in something like a Bigelow Sundancer module. Heck, you could just build it after you orbited the module, inside the module. You could have an artificial-gravity section of the module where sleeping, exercising, and perhaps other activities that could benefit from artificial gravity (like fixing or making something... most rapid manufacturing techniques rely on gravity). Also, if even idle activity in artificial gravity is found to be helpful, computers and desks could be placed in the artificial gravity section.The ring wouldn't need to be sealed at all (in fact, it would best not be sealed), and should be able to be spun-down at any time. Any structural considerations should be handled by the structure of the ring.Just an idea.EDIT: Part of the benefit of this idea is that the whole artficial gravity mechanical system would be inside a pressurized environment, and thus could be fixed mid-flight using conventional hand tools without a difficult and risky EVA.Current BA 330 design is too small to accommodate an internal centrifuge. It *could* be done, with 6RPM you are looking at 0.12g, with 8, 0.2g. I would suggest a 10m diameter hab as a minimum (2001 Discovery centrifuge size). At these sizes, too *low* an RPM causes problems with Coriolis forces and walking speeds. But perhaps these aren't as big problems as we think they are.A couple of rings of fluid around the rotation axis should keep instabilities down.Gasbarri P., Teofilatto P. (2009) Fluid ring dampers for artificial gravity spacecraft. Acta Astronautica (64), 1286-1292
I agree that astronauts can probably adapt to ~5-10rpm, which should be good enough for Mars-level gravity in something like a Bigelow Sundancer module. Heck, you could just build it after you orbited the module, inside the module. You could have an artificial-gravity section of the module where sleeping, exercising, and perhaps other activities that could benefit from artificial gravity (like fixing or making something... most rapid manufacturing techniques rely on gravity). Also, if even idle activity in artificial gravity is found to be helpful, computers and desks could be placed in the artificial gravity section.The ring wouldn't need to be sealed at all (in fact, it would best not be sealed), and should be able to be spun-down at any time. Any structural considerations should be handled by the structure of the ring.Just an idea.EDIT: Part of the benefit of this idea is that the whole artficial gravity mechanical system would be inside a pressurized environment, and thus could be fixed mid-flight using conventional hand tools without a difficult and risky EVA.
The ISRU fuel plant converts Kerogen and Water into LOX and Kerosene (or methane if easier). Then crew ships (and later Mars ships) are fueled up on Phobos. Crew ships then go from Mars to Earth Moon L1 and back on this fuel load.
From alexterrell:QuoteThe ISRU fuel plant converts Kerogen and Water into LOX and Kerosene (or methane if easier). Then crew ships (and later Mars ships) are fueled up on Phobos. Crew ships then go from Mars to Earth Moon L1 and back on this fuel load.It might be unwise to make this an important part of your architecture until we have a better idea of what Phobos is actually made of.
One scenario is that Phobos is resource rich, but buried by 100s of metres in dessicated carbon free dust.
Quote from: alexterrell on 10/09/2010 12:07 pmOne scenario is that Phobos is resource rich, but buried by 100s of metres in dessicated carbon free dust. Then we would need to know what the dust is. With a bit of thought practically anything that burns can be turned into rocket fuel, although the Isp may be low. If the material can be converted into a solid say by pressure or melting then it can be used for construction purposes. Phobos is in a shallow gravity well so even non-reactivate asbestos could be used as say a heat shield on the Mars landers.