Quote from: envy887 on 04/28/2018 05:26 pmThe Shuttle could not deliver 20,000 kg of pressurized upmass to ISS. A fully loaded MPLM held more like 13,000 kg of cargo.Assuming $500M for a Shuttle launch, that works out to $38,500/kg.
The Shuttle could not deliver 20,000 kg of pressurized upmass to ISS. A fully loaded MPLM held more like 13,000 kg of cargo.
It’s worth noting that many an internet discussion about the cost of commercial cargo to the ISS have failed to draw the distinctions that make for rigorous analysis, or even trying to account for major factors. Common errors include using the Space Shuttle programs historical average cost per flightd to calculate costs per kg to the ISS at a low yearly flight rate as a multiple of that average, incorrectly treating the Shuttle’s per flight costs as if NASA could purchase those flights by the yard. To make matters worse, other common errors forget that Shuttle upgrades, though not a recurring yearly operational cost, were a large, ever present and continuous capital expense in every yearly budget. Operating a Shuttle meant continually funding Shuttle upgrades. Other typical errors include using the Shuttle’s maximum payload (not cargo) of about 27,500kg to Low Earth Orbit (LEO) at 200km, then comparing against the commercial prices for ISS cargo (not payload) delivered to the actual, higher 400km ISS orbit. With errors like these such analysis are incorrect (though “not even wrong” might also apply.)
Quote from: Steven Pietrobon on 04/29/2018 02:10 amQuote from: envy887 on 04/28/2018 05:26 pmThe Shuttle could not deliver 20,000 kg of pressurized upmass to ISS. A fully loaded MPLM held more like 13,000 kg of cargo.Assuming $500M for a Shuttle launch, that works out to $38,500/kg.From Zapata-Assessment of Cost Improvements in NASA COTS CRS.pdf posted above:QuoteIt’s worth noting that many an internet discussion about the cost of commercial cargo to the ISS have failed to draw the distinctions that make for rigorous analysis, or even trying to account for major factors. Common errors include using the Space Shuttle programs historical average cost per flightd to calculate costs per kg to the ISS at a low yearly flight rate as a multiple of that average, incorrectly treating the Shuttle’s per flight costs as if NASA could purchase those flights by the yard. To make matters worse, other common errors forget that Shuttle upgrades, though not a recurring yearly operational cost, were a large, ever present and continuous capital expense in every yearly budget. Operating a Shuttle meant continually funding Shuttle upgrades. Other typical errors include using the Shuttle’s maximum payload (not cargo) of about 27,500kg to Low Earth Orbit (LEO) at 200km, then comparing against the commercial prices for ISS cargo (not payload) delivered to the actual, higher 400km ISS orbit. With errors like these such analysis are incorrect (though “not even wrong” might also apply.)The analysis shows an apple to apple comparison gives ~$272,000 per kg for Shuttle with MPLM.
Quote from: Steven Pietrobon on 04/29/2018 02:10 amQuote from: envy887 on 04/28/2018 05:26 pmThe Shuttle could not deliver 20,000 kg of pressurized upmass to ISS. A fully loaded MPLM held more like 13,000 kg of cargo.Assuming $500M for a Shuttle launch, that works out to $38,500/kg..Multiple errors in your post. A fully loaded MPLM weighed between 13 to 14 metric tons, including cargo. MPLM's empty weight was a little over 4,000 kg. So, that boiles down to just 9,000 to 10,000 kg of cargo capacity for a single MPLM.https://www.nasa.gov/mission_pages/station/structure/elements/mplm.htmlAlso, space shuttle historic overviews have shown that the average shuttle mission cost roughly $1B.These two figures combined boil down to something like $100,000/kg. for cargo-to-ISS via shuttle. That is substantially more expensive than CRS-1 (and CRS-2).
Multiple errors in your post. A fully loaded MPLM weighed between 13 to 14 metric tons, including cargo. MPLM's empty weight was a little over 4,000 kg. So, that boiles down to just 9,000 to 10,000 kg of cargo capacity for a single MPLM.
Also, space shuttle historic overviews have shown that the average shuttle mission cost roughly $1B.
Quote from: woods170 on 04/29/2018 05:50 pmMultiple errors in your post. A fully loaded MPLM weighed between 13 to 14 metric tons, including cargo. MPLM's empty weight was a little over 4,000 kg. So, that boiles down to just 9,000 to 10,000 kg of cargo capacity for a single MPLM.I was only using the value quoted previously. Thanks for the correction.QuoteAlso, space shuttle historic overviews have shown that the average shuttle mission cost roughly $1B.NASA was not spending $4B a year launching shuttles in the latter part of the program when it was flying four missions a year! That $1B is the average over the entire program. It was more like $2B a year for four missions, so $500M a mission. That gives a cost of $50,000/kg to $55,600/kg. Had the Space Shuttle been privatised and flown robotically, the price may have been even less.
For Fiscal Year 2010, the average cost to prepare and launch a shuttle mission was approximately $775 million.
What were the per-kg costs for Shuttle delivering cargo payload again? Anyone know?
One number in the OIG report that struck me (and I'd like to know if it's accurate) is the unpressurized upmass for Dragon 2. It's shown as 800kg, which is far less than they've carried in the Dragon 1 trunk (BEAM was about 1400kg). I wonder if that number is just what was left over after subtracting the theoretical pressurized upmass from the total upmass, and maybe they can carry a heavier load in the trunk if the pressurized upmass is less? Otherwise that would be a fairly large decrease in utility of the trunk for unpressurized payloads.
Quote from: woods170 on 04/29/2018 05:50 pmQuote from: Steven Pietrobon on 04/29/2018 02:10 amQuote from: envy887 on 04/28/2018 05:26 pmThe Shuttle could not deliver 20,000 kg of pressurized upmass to ISS. A fully loaded MPLM held more like 13,000 kg of cargo.Assuming $500M for a Shuttle launch, that works out to $38,500/kg..Multiple errors in your post. A fully loaded MPLM weighed between 13 to 14 metric tons, including cargo. MPLM's empty weight was a little over 4,000 kg. So, that boiles down to just 9,000 to 10,000 kg of cargo capacity for a single MPLM.https://www.nasa.gov/mission_pages/station/structure/elements/mplm.htmlAlso, space shuttle historic overviews have shown that the average shuttle mission cost roughly $1B.These two figures combined boil down to something like $100,000/kg. for cargo-to-ISS via shuttle. That is substantially more expensive than CRS-1 (and CRS-2).The Shuttle could carry cargo other than in the MPLM. According to Zapata, "the average flight of an Orbiter / MPLM delivered 13,841 kg of cargo to the ISS per flight". The Shuttle also had very high fixed costs. Zapata estimates that 1 flight per year on Shuttle would cost $5.046 billion in 2017, with each additional flight up to 5 flights adding about $399 million. So even though Shuttle could deliver more cargo than CRS, and even though its marginal cost per flight is similar to CRS, there was no possible way for NASA to keep Shuttle operational without MUCH higher overall costs than CRS and CC combined: about $5.5 billion at minimum to meet ISS needs with Shuttle, vs $2.0 billion total for both crew and cargo on commercial providers.
This is absolutely non-sensical. Shuttle was servicing and building the ISS for about 4 billion per year in the years before retirement. Adjusting for inflation, that is 4.5 billion per year in 2017.
Quote from: A12 on 08/07/2018 10:04 amProbably already asked multiple Times, of so, please point me to the right thread/messageI read the upcoming cargo flights will be flown with D2.What about the different size of berthing passage when compared to the smaller docking one ?Will be largest cargo moved to Cygnus ?There will be Dragon1 missions until Spx-20. I recall SpaceX or NASA saying that most cargo can be divided into smaller bags or containers, etc., so the fact that cargo D2 will dock (and not berth) isn't much of an issue. Incidentally, I think that DC will initially berth (even though it it is also able to dock). So 2 out of 3 spacecrafts for CRS2 will initially berth.
Probably already asked multiple Times, of so, please point me to the right thread/messageI read the upcoming cargo flights will be flown with D2.What about the different size of berthing passage when compared to the smaller docking one ?Will be largest cargo moved to Cygnus ?
https://twitter.com/spcplcyonline/status/1107674387229093889File attached
KEY ACHIEVEMENTS PLANNED FOR FY 2021NASA expects five commercial resupply flights, including the first Sierra Nevada CRS-2 flight, to deliver research and logistics hardware in FY 2021. Northrop Grumman plans to launch two commercial resupply flights and complete 11 performance milestones in support of five CRS-2 flights. SpaceX plans to launch two commercial resupply flights and complete 13 performance milestones in support of seven CRS-2 flights. Sierra Nevada plans to launch one commercial resupply flight and complete five performance milestones in support of three CRS-2 flights.
From FY2021 budget request, page 219 (LSO-32):QuoteKEY ACHIEVEMENTS PLANNED FOR FY 2021NASA expects five commercial resupply flights, including the first Sierra Nevada CRS-2 flight, to deliver research and logistics hardware in FY 2021. Northrop Grumman plans to launch two commercial resupply flights and complete 11 performance milestones in support of five CRS-2 flights. SpaceX plans to launch two commercial resupply flights and complete 13 performance milestones in support of seven CRS-2 flights. Sierra Nevada plans to launch one commercial resupply flight and complete five performance milestones in support of three CRS-2 flights.I think the initial award is 6 missions, does this mean NASA ordered more CRS-2 flights from SpaceX?