Quote from: cebri on 03/19/2017 07:58 pmQuick question. On their webpage SX states F9 can carry 22,800 kg to LEO, however in their user guide they also state that the heavy PAF can only support up to 10,886 kg. My question would be: Can the F9 really carry 22mT into orbit? Or there would be some structural limitation that prevents it?The payload to LEO is mostly a yardstick to compare performance of different rockets. Its a mostly notional numberI think that's a 200Km LEO orbit.Typical launches to LEO (except for ISS) are to 500Km and higher orbits, that would eat a few tons off that figure.Add margins for ASDS recovery (which doubles as a safety margin for engine off), and the realistic figure would be 17 tons or less.If a customer approached SX with the requirement for even 20 tons to 200Km LEO orbit , they would be offered a FH launch instead.200Km orbits are unstable with just enough atmospheric drag to re-enter within a few years.
Quick question. On their webpage SX states F9 can carry 22,800 kg to LEO, however in their user guide they also state that the heavy PAF can only support up to 10,886 kg. My question would be: Can the F9 really carry 22mT into orbit? Or there would be some structural limitation that prevents it?
Quote from: macpacheco on 03/19/2017 08:53 pmQuote from: cebri on 03/19/2017 07:58 pmQuick question. On their webpage SX states F9 can carry 22,800 kg to LEO, however in their user guide they also state that the heavy PAF can only support up to 10,886 kg. My question would be: Can the F9 really carry 22mT into orbit? Or there would be some structural limitation that prevents it?The payload to LEO is mostly a yardstick to compare performance of different rockets. Its a mostly notional numberI think that's a 200Km LEO orbit.Typical launches to LEO (except for ISS) are to 500Km and higher orbits, that would eat a few tons off that figure.Add margins for ASDS recovery (which doubles as a safety margin for engine off), and the realistic figure would be 17 tons or less.If a customer approached SX with the requirement for even 20 tons to 200Km LEO orbit , they would be offered a FH launch instead.200Km orbits are unstable with just enough atmospheric drag to re-enter within a few years.Another way to look at capability is to see what Falcon 9 has actually lifted. So far, max payload to LEO x 51.6 deg has been somewhere around 9.3 tonnes, maybe (SpaceX doesn't announce Dragon liftoff mass so this is based on cargo plus dated Dragon information from SpaceX). This was with first stage recovery downrange. In addition, we've just seen an expendable Falcon 9 boost 5,600 kg (or so) to GTO. - Ed Kyle
Another way to look at capability is to see what Falcon 9 has actually lifted. So far, max payload to LEO x 51.6 deg has been somewhere around 9.3 tonnes, maybe (SpaceX doesn't announce Dragon liftoff mass so this is based on cargo plus dated Dragon information from SpaceX). This was with first stage recovery downrange. In addition, we've just seen an expendable Falcon 9 boost 5,600 kg (or so) to GTO. - Ed Kyle
Quote from: edkyle99 on 03/20/2017 01:30 pmAnother way to look at capability is to see what Falcon 9 has actually lifted. So far, max payload to LEO x 51.6 deg has been somewhere around 9.3 tonnes, maybe (SpaceX doesn't announce Dragon liftoff mass so this is based on cargo plus dated Dragon information from SpaceX). This was with first stage recovery downrange. In addition, we've just seen an expendable Falcon 9 boost 5,600 kg (or so) to GTO. - Ed Kyle5,600kg to GTO is a lot lower than their advertised 8,300kg. And I was under the (false) impression that the advertised payloads were with recovered booster. something is definitely amiss here. If they could truly put 8,300kg into GTO expendable then I really doubt they would have had to remove the legs etc for 5.600kg. Am I correct in that they are not chilling the LOX as much as originally planned, and could there be THAT much difference for just colder LOX?
Iridium was 9,600 kg to 625 km polar LEO with downrange landing. Much higher performance than Dragon to ISS.
Quote from: envy887 on 03/20/2017 03:37 pmIridium was 9,600 kg to 625 km polar LEO with downrange landing. Much higher performance than Dragon to ISS.I have that as 8,600 kg (ten 860 kg satellites) to 610 x 620 km x 86.4 deg.Pardon me if I'm repeating someone else, but the SpaceX web site numbers are for fully expendable Block 5, which hasn't begun flying to date. The current v1.2 (Block 3) variant presumably has less capability. - Ed Kyle
Quote from: edkyle99 on 03/20/2017 08:29 pmQuote from: envy887 on 03/20/2017 03:37 pmIridium was 9,600 kg to 625 km polar LEO with downrange landing. Much higher performance than Dragon to ISS.I have that as 8,600 kg (ten 860 kg satellites) to 610 x 620 km x 86.4 deg.Pardon me if I'm repeating someone else, but the SpaceX web site numbers are for fully expendable Block 5, which hasn't begun flying to date. The current v1.2 (Block 3) variant presumably has less capability. - Ed Kyleplus the 1,000-kg satellite dispenser.
Quote from: whitelancer64 on 03/20/2017 08:35 pmQuote from: edkyle99 on 03/20/2017 08:29 pmQuote from: envy887 on 03/20/2017 03:37 pmIridium was 9,600 kg to 625 km polar LEO with downrange landing. Much higher performance than Dragon to ISS.I have that as 8,600 kg (ten 860 kg satellites) to 610 x 620 km x 86.4 deg.Pardon me if I'm repeating someone else, but the SpaceX web site numbers are for fully expendable Block 5, which hasn't begun flying to date. The current v1.2 (Block 3) variant presumably has less capability. - Ed Kyleplus the 1,000-kg satellite dispenser.This, or some of this, might represent potential payload mass on future, single-satellite missions, but it was non-revenue on this flight - like the seats on an airplane that hold the paying customers, little different from the usual payload attach fitting and as far as the rocket equation is concerned the same as upper stage burnout mass. - Ed Kyle
http://spacenews.com/china-studying-reusable-rockets-similar-to-spacex/[/size]"Chinese researchers said they looked into making a powered landing of the first stage, as SpaceX does with the Falcon 9, but concluded it was 'extremely difficult' and inefficient.A concept being developed would use parachutes to slow down first stages after separation, then deploy an airbag to cushion the stage’s landing on dry land. "http://www.scmp.com/news/china/policies-politics/article/2079822/china-developing-system-recover-reuse-parts-space"multiple censors [sic] and a flight control system guide the descent"English is a tough language but "multiple censors" in China is an amusing mistake.The animation shows them recovering the ground-lit solid rockets.Parachutes and airbags.... So what SpaceX has done is judged to be too difficult for the Chinese with their tens of thousands of people working on the problem.
http://spacenews.com/china-studying-reusable-rockets-similar-to-spacex/[/size]"Chinese researchers said they looked into making a powered landing of the first stage, as SpaceX does with the Falcon 9, but concluded it was 'extremely difficult' and inefficient.
A concept being developed would use parachutes to slow down first stages after separation, then deploy an airbag to cushion the stage’s landing on dry land. "
This, or some of this, might represent potential payload mass on future, single-satellite missions
Forgive me if this has been discussed before. Why did SpaceX leave their Kwajalein Atoll launch site? I know it's remote (guess they don't make them any more remote) but the advantage of a near equator launch site, no range conflicts, and a lack of traffic and lookey loos would seem to be a clear advantage.