Quote from: TrevorMonty on 08/30/2014 07:47 pmAny near term (10yr) lunar base is most likely to be a commercial venture eg Bigelow. To be viable its going to have rely on commercial LVs. How so? Given there isn't really a business case to support such an effort unless it was "paid-for" by a government agency. Bigelow has yet to "prove" a case for LEO business let alone BLEO.Randy
Any near term (10yr) lunar base is most likely to be a commercial venture eg Bigelow. To be viable its going to have rely on commercial LVs.
Whatever you do don't warm up that tank with a match...
Whereas the confirmed monazite on the Moon is confined to trace fractions in rare, tiny phosphate-rich clasts...
Jeff Greason low cost lunar mission architecture also a low cost Mars mission. {snip}Some interesting points on the Centuar upper stage, with no payload they arrive at LEO >90% full.He was talking about 2 Atlas launches plus one F9. If you use FH the crew capsule can go straight to EML1 staging point so only requiring 1 Atlas launch. The FH maybe able to recover its 2 boosters reducing the cost even more.Because the Atlas doesn't have any payload, launch costs should be <$100m., ie put a 1st and 2nd stage together fuel and launch, doesn't get much simpler than that. The only radically new architecuture need for this mission is Lunar Lander and Mastens Xeus would fit the bill perfectly and should cost billions to develop. If this Centaur upper stages are using XCOR engines all the better for Jeff.
Robert Farquhar, the developer of the EML2 lunar trajectory architecture, passed away on Sunday, October 18 at the age of 83.http://www.spaceref.com/news/viewpr.html?pid=47103
Queqiao was developed by the China Academy of Space Technology (CAST). It is planned to take a lunar swing-by transfer trajectory to insert into an Earth-Moon L2 halo orbit about 8 or 9 days after launch. The L2 point is about 450,000 kilometers away from Earth and more than 60,000 kilometers away from the lander and rover on the lunar farside. An Earth-Moon L2 halo orbit is ideal for Queqiao because it can 1) provide nearly continuous contact between both lunar farside and Earth ground station, 2) get continuous illumination from the Sun, avoiding eclipses, and 3) requires little energy to maintain its orbit over the long term. The concept of using an L2 halo orbit as the location for a lunar farside data-relay satellite was proposed more than 40 years ago by Robert Farquhar, a NASA mission design specialist, and the fantastic design is finally expected to be realized by Queqiao. If successful, Queqiao will be the first-ever relay satellite at this location for lunar relay communication.
The Beijing Aerospace Control Centre (BACC) issued the command at 21:32 Beijing time (13:32 UTC), and by 21:46 confirmed through telemetry that Queqiao had performed the burn and entered a transfer orbit towards the second Earth-Moon Lagrange point, People's Liberation Army Daily reported. The spacecraft passed the Moon at 100 km above the surface at closest approach. Failure to perform the braking manoeuvre would have seen the spacecraft head back towards the Earth.
The Role of the Cis-Lunar Libration point.TL;DREML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.
Quote from: JohnFornaro on 09/21/2020 01:28 pmEML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.Or, one of my 200m diameter rotating space stations that rotate at 2.5 RPM.Still pretty big, so maybe start with my Mars gravity station that is only 100m in diameter, and rotates at 2.5 RPM? The Mars gravity station could provide some R&R for astronauts returning from extended stays on the Moon, and before they head home. Just a suggestion...
EML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.
2.5 rpm is on the verge of creating nausea. Still the station must be built one piece at a time. My thought was that first there was a hub, then two cylindrical sections connected to the hub by 500 yard tethers, and the rotation started. Fill in the sections in a methodical fashion. There would be a lunar gravity ring, and also a Mars gravity ring. Anyhow...
...acceptable range of diameter/rpm parameters...
Quote from: JohnFornaro on 09/22/2020 11:43 am2.5 rpm is on the verge of creating nausea. Still the station must be built one piece at a time. My thought was that first there was a hub, then two cylindrical sections connected to the hub by 500 yard tethers, and the rotation started. Fill in the sections in a methodical fashion. There would be a lunar gravity ring, and also a Mars gravity ring. Anyhow...Is there a reference somewhere on what the acceptable range of diameter/rpm parameters is?I found a youtube vid which shows a "comfort zone", I don't know how valid that is (skip to 26:56 for summary chart) *snip youtube link*