Quote from: A_M_Swallow on 10/17/2017 03:08 am]The DSG could be used to build the lunar base. For example the SLS would throw 40 tonne habitats to the DSG. The station's reusable lander would take the habitats down to the lunar surface. Same for heavy cargoes going to Mars.Building the DSG 10 tonnes at a time is just using Orion on SLS as a Shuttle building the ISS. With a heavy lift launch vehicle lift most of the spacestation in a single launch, like SKYLAB. Enhancements like refuelling facilities may need additional launches.Agreed it would be better the assemble DSG from Skylab sized sections since SLS can lift them.I think it would be best to assemble DSG in LEO then attach an ion tug or a mostly full EUS to it and take it to lunar vicinity.LEO rendezvous and assembly is old hat.
]The DSG could be used to build the lunar base. For example the SLS would throw 40 tonne habitats to the DSG. The station's reusable lander would take the habitats down to the lunar surface. Same for heavy cargoes going to Mars.Building the DSG 10 tonnes at a time is just using Orion on SLS as a Shuttle building the ISS. With a heavy lift launch vehicle lift most of the spacestation in a single launch, like SKYLAB. Enhancements like refuelling facilities may need additional launches.
Quote from: Patchouli on 10/18/2017 02:18 amQuote from: A_M_Swallow on 10/17/2017 03:08 am]The DSG could be used to build the lunar base. For example the SLS would throw 40 tonne habitats to the DSG. The station's reusable lander would take the habitats down to the lunar surface. Same for heavy cargoes going to Mars.Building the DSG 10 tonnes at a time is just using Orion on SLS as a Shuttle building the ISS. With a heavy lift launch vehicle lift most of the spacestation in a single launch, like SKYLAB. Enhancements like refuelling facilities may need additional launches.Agreed it would be better the assemble DSG from Skylab sized sections since SLS can lift them.I think it would be best to assemble DSG in LEO then attach an ion tug or a mostly full EUS to it and take it to lunar vicinity.LEO rendezvous and assembly is old hat.The block 1 SLS can lift 70 tonnes to LEO, later versions 105 tonnes. IMHO That is a reasonable size for a mini spacestation.The first module of the DSG is the Power and Propulsion Element (PPE). With a few minor changes, like the guidance system, that is a space tug in its own right.Whether a 50kW SEP (Solar Electric Propulsion) is sufficient to push 105 tonnes out of LEO I do not know. The SEP will probably have been sized for station keeping in lunar orbit.
A 500kw array would be how large compared to the ISS 'acreage' of panels?
By my calcs (2.5 N per 50 kW, 8.0 km/s dv required) it would take a 50 kW thruster 10 years to move 100 tonnes from LEO to LLO.But with a much larger 1.5 MW array and 75 N worth of state-of-the-art ion thrusters it could be done in about 4 months.
The block 1 SLS can lift 70 tonnes to LEO, later versions 105 tonnes. IMHO That is a reasonable size for a mini spacestation.
Quote from: A_M_Swallow on 10/18/2017 11:57 amThe block 1 SLS can lift 70 tonnes to LEO, later versions 105 tonnes. IMHO That is a reasonable size for a mini spacestation.The 105 t is the IMLEO, including the EUS. The payload mass is about 93 t.
The DSG could be used to build the lunar base. For example the SLS would throw 40 tonne habitats to the DSG. The station's reusable lander would take the habitats down to the lunar surface. Same for heavy cargoes going to Mars.
Quote from: ncb1397 on 10/17/2017 06:02 pm13 payloadsNo.Only five are partially or fully funded through HEOMD.
13 payloads
The Administration's proposed cut to NASA's 2018 topline was based on program terminations and content reduction, not old development programs ending.
For 2018, the White House proposed eliminating NASA's entire education program, terminating several earth science missions in development, and turning off earth science instruments on other operational missions.
Whether it comes out of JAXA's budget or HEOMD, effect on overall NASA led exploration may be the same/similar.
Even if you don't count the end of the education program, we are still talking about a pretty large drop, especially when you account for inflation. U.S. Inflation in 2017 was about 2.2%, which means the 2017 budget of 19.653 billion would be equivalent to the 19.993 billion
The NASA 2017 budget request put cargo and crew transportation
Quote from: ncb1397 on 10/19/2017 05:33 pmEven if you don't count the end of the education program, we are still talking about a pretty large drop, especially when you account for inflation. U.S. Inflation in 2017 was about 2.2%, which means the 2017 budget of 19.653 billion would be equivalent to the 19.993 billionUnfortunately, this is unrealistic for planning purposes.NASA's budget has not kept pace with inflation for decades.
Quote from: UltraViolet9 on 10/19/2017 08:26 pmQuote from: ncb1397 on 10/19/2017 05:33 pmEven if you don't count the end of the education program, we are still talking about a pretty large drop, especially when you account for inflation. U.S. Inflation in 2017 was about 2.2%, which means the 2017 budget of 19.653 billion would be equivalent to the 19.993 billionUnfortunately, this is unrealistic for planning purposes.NASA's budget has not kept pace with inflation for decades.Plugging NASA's 2000 funding amount into a government CPI calculator yields a different conclusion:https://data.bls.gov/cgi-bin/cpicalc.pl?cost1=13428&year1=200001&year2=201701NASA budget from beginning of the century to 2017 was inflation adjusted and then some. I used CPI for my inflation calculations above.edit: It is also good to keep Apollo costs in mind in these discussions:ranked by expense:Saturn V: 6.4 BCSM: 3.7 BLEM: 2.2 BSkylab: 2.2 BLRV: .038 BYou could almost fund the LEM, Skylab and the LRV for the cost of the CSM. Likewise, you could possibly get away with funding the DSG, a lander and a rover for what is spent on Orion( $1.2 B/year). For reference, this would be a 2018 budget of 2017 enacted + inflation + $400 million. Not several billion dollars.
NASA budget from beginning of the century to 2017 was inflation adjusted and then some.
Quote from: ncb1397 on 10/19/2017 09:12 pmNASA budget from beginning of the century to 2017 was inflation adjusted and then some.No.Based on a CPI website, NASA's FY 2017 budget gets NASA back to its FY 2000 budget, plus inflation. But that's the wrong inflator for NASA or the aerospace sector overall; FY 2000 is a low point in NASA's annual budget; and most importantly, there was no steady inflationary increase year-on-year during this time period. The area under the curve that matters much more than the endpoints.Even with a cherry-picked inflator and starting point, NASA's buying power in the intervening years did not keep pace with inflation. In fact, in some of these years, NASA's budget actually shrank, even in constant dollars (forget inflation).
Quote from: UltraViolet9 on 10/26/2017 10:04 pmEven with a cherry-picked inflator and starting point, NASA's buying power in the intervening years did not keep pace with inflation. In fact, in some of these years, NASA's budget actually shrank, even in constant dollars (forget inflation). I think we are in agreement then. I don't really count a inflation adjustment as a budget increase, because it just counteracts the fall in the value of the dollar. But yes, they need some sort of yearly increase(in nominal terms) in order to fund additional exploration elements ultimately totaling several billion dollars on an annual basis. I mean, going back to the 1966 budget of ~6 billion USD just isn't feasible. Obviously, NASA is screwed without a "cost of living" adjustment. But they are getting, on average, yearly increases given the 1966 budget of 6 billion and the 2017 budget of ~19-20 billion. Goes without saying that it didn't keep up with inflation, especially between those two end points.
Even with a cherry-picked inflator and starting point, NASA's buying power in the intervening years did not keep pace with inflation. In fact, in some of these years, NASA's budget actually shrank, even in constant dollars (forget inflation).
NASA signed final ten-year contracts for developing the Space Station in September 1988, and the project was finally moving into the hardware fabrication phase.
But yes, they need some sort of yearly increase(in nominal terms) in order to fund additional exploration elements ultimately totaling several billion dollars on an annual basis.
European space officials outline desired contribution to Deep Space Gateway:http://spacenews.com/european-space-officials-outline-desired-contribution-to-deep-space-gateway/