Capsule: 10.4 mT, Service Module: 15.5 mT, SM Propellant: 9.3 mT, LAS: 7.3 mT, 4 Crew + supplies: 1.0 mT. Orion Spacecraft Total: 41.8 mT ...
Quote from: clongton on 05/30/2017 04:50 pmCapsule: 10.4 mT, Service Module: 15.5 mT, SM Propellant: 9.3 mT, LAS: 7.3 mT, 4 Crew + supplies: 1.0 mT. Orion Spacecraft Total: 41.8 mT ...I don't think this is correct. Orion is intended to have 1250 to 1300 m/s of delta-v plus margins, but this mass total (34.5 t fueled after discarding LAS, and 25.2 t dry) only allows <1000 m/s with 319s specific impulse.If the fueled mass is 25.2 t after discarding LAS and 15.9 tonnes dry then it has 1440 m/s delta-v. Much more in line with Orion's expected capabilities.I think the mass of stage adapters and SM fairings is also missing, and has to be accounted for to fly on an EELV class rocket.
Quote from: envy887 on 05/30/2017 08:38 pmQuote from: clongton on 05/30/2017 04:50 pmCapsule: 10.4 mT, Service Module: 15.5 mT, SM Propellant: 9.3 mT, LAS: 7.3 mT, 4 Crew + supplies: 1.0 mT. Orion Spacecraft Total: 41.8 mT ...I don't think this is correct. Orion is intended to have 1250 to 1300 m/s of delta-v plus margins, but this mass total (34.5 t fueled after discarding LAS, and 25.2 t dry) only allows <1000 m/s with 319s specific impulse.If the fueled mass is 25.2 t after discarding LAS and 15.9 tonnes dry then it has 1440 m/s delta-v. Much more in line with Orion's expected capabilities.I think the mass of stage adapters and SM fairings is also missing, and has to be accounted for to fly on an EELV class rocket.Chuck has the figures for the SM off. It's mass is 15.5 mT INCLUDING propellant. (6.2 mT dry weight).Fully fueled weight of Orion (with Crew + supplies, but without LAS) ~ 27 mT.A sub-fueled one with just two Crew members and reduced supplies for short LEO mission weighs approx. 4mT less.
So it turns out there will be crew on SLS/Orion EM-1: Living, breathing plants. They will help study the effects of radiation.
So which of the following stated values for SLS 1B is the right one to use 39.2mt to TLI or 45mt to EM-2. Your values for Orion + SM is 42.5mt. That leaves just 2.5mt for a rideshare payload to EM-2. Something is wrong about these numbers if NASA keeps saying it can launch DSG elemnts with Orion to a Lunar orbit as long as the DSG element is <10mt.
This seems to have gone missing, so repost.[... rocket comparison table]
Everyone's talking a lot about EM-1 and EM-2, but where does Europa Clipper fit into the schedule currently? Is it even slated for an SLS launch anymore?
Quote from: IanThePineapple on 07/12/2017 02:16 amEveryone's talking a lot about EM-1 and EM-2, but where does Europa Clipper fit into the schedule currently? Is it even slated for an SLS launch anymore?As far as the latest, its still set for SLS launch by law. There seems to be some hope to fly it before EM-2, but it could also fly after it.
Quote from: A_M_Swallow on 03/30/2017 02:29 amHowever this launch still feels like people were finding something for the SLS to do whilst the Deep Space Habitat modules are developed.... [Quote truncated by Proponent]But you will say this no matter what mission is selected for SLS.
However this launch still feels like people were finding something for the SLS to do whilst the Deep Space Habitat modules are developed....
Quote from: okan170 on 07/12/2017 02:56 amQuote from: IanThePineapple on 07/12/2017 02:16 amEveryone's talking a lot about EM-1 and EM-2, but where does Europa Clipper fit into the schedule currently? Is it even slated for an SLS launch anymore?As far as the latest, its still set for SLS launch by law. There seems to be some hope to fly it before EM-2, but it could also fly after it.It's my understanding that JPL has not yet selected the launch vehicle. If I am out of date or otherwise wrong, I would very much appreciate a pointer to the correct information.Another thing that would be interesting to know is the precise legal language connecting SLS with Europa Clipper. Is is something like the requirement in the 2010 Authorization Act that Shuttle-derived hardware shall be used "to the maximum extent practicable"? In other words, to what extent has Congress predetermined the conclusions that JPL's engineers will reach?
OK, so it sounds like Congress has in fact determined what JPL will conclude. There isn't even any wiggle room, like "to the extent practicable."[joke]Once again, America is very fortunate to have such brilliant and omniscient politicians, capable of performing in-depth technical analyses! Who needs engineers or scientists![/joke]
Quote from: Proponent on 07/12/2017 12:03 pmOK, so it sounds like Congress has in fact determined what JPL will conclude. There isn't even any wiggle room, like "to the extent practicable."[joke]Once again, America is very fortunate to have such brilliant and omniscient politicians, capable of performing in-depth technical analyses! Who needs engineers or scientists![/joke]Congressional representatives have to find something to use SLS for if they want to justify keeping it - and the jobs it provides in their districts - in production. The Deep Space Gateway and missions like the Europa orbiter and lander accomplish that goal. To the people doling out the money, IMHO, the engineering and science are secondary considerations (if that).
Also, we're pretty convinced the SRBs won't be painted (like the Falcon 9 and FH landing legs from those old renders), right?
Quote from: Khadgars on 03/31/2017 08:48 pmQuote from: A_M_Swallow on 03/30/2017 02:29 amHowever this launch still feels like people were finding something for the SLS to do whilst the Deep Space Habitat modules are developed.... [Quote truncated by Proponent]But you will say this no matter what mission is selected for SLS.It's a perfectly reasonable statement, given that:1. The mission is being undertaken only after SLS's development has consumed over $10 billion and five years;
]2. There has been (correct me if I'm wrong) no consideration of accomplishing the same thing without SLS;
3. A DSH seems reasonable only in the current context: had it been proposed in 2011 as a 15-year-horizon objective for SLS, it would have seemed ridiculous for being so underwhelming.