Clamp-o-Tron Posted December 3, 2020 Share Posted December 3, 2020 IIRC SpaceX prefers droneship landings over RTLS because it puts less stress on the booster. I'll try to find a source for that. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 3, 2020 Share Posted December 3, 2020 1 minute ago, Clamp-o-Tron said: IIRC SpaceX prefers droneship landings over RTLS because it puts less stress on the booster. I'll try to find a source for that. Wouldn't an RTLS have lower entry velocity and therefore put less stress on the booster? Also, recovery operations are much easier with RTLS as they don't have to operate out at sea. Quote Link to comment Share on other sites More sharing options...
Clamp-o-Tron Posted December 3, 2020 Share Posted December 3, 2020 13 minutes ago, RealKerbal3x said: Wouldn't an RTLS have lower entry velocity and therefore put less stress on the booster? Also, recovery operations are much easier with RTLS as they don't have to operate out at sea. I can't find the source for it now, but I did hear it somewhere. Something about entry angle? Also, there are a lot of expenses associated with RTLS that you don't have to worry about with droneship. (FAA regulations, evacuation of the area, recovery operations (still not cheap to roll it back to the HIF!), and booster safing. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted December 3, 2020 Share Posted December 3, 2020 13 hours ago, YNM said: What docking / berthing adapter is it equipped with ? The main thrusters are still on the front, right ? And the side Draco thrusters are still in place. They're just covered in protective tape for right now. It's only the SuperDracos that are removed. It will have the same forward adapter, though. 43 minutes ago, Clamp-o-Tron said: IIRC SpaceX prefers droneship landings over RTLS because it puts less stress on the booster. I'll try to find a source for that. Less high-gee firing time, I suppose? Firing the engines with the upper stage attached doesn't stress the booster as much because there's less gee-loading. Once the upper stage is gone, the boostback burn is a stressor. Eliminating that means less loading on the upper stage. Quote Link to comment Share on other sites More sharing options...
Geonovast Posted December 3, 2020 Share Posted December 3, 2020 40 minutes ago, RealKerbal3x said: Wouldn't an RTLS have lower entry velocity and therefore put less stress on the booster? Also, recovery operations are much easier with RTLS as they don't have to operate out at sea. Drone ship landings don't have a boostback burn, so that may be a consideration. It is odd though, since AFAIK all previous CRS missions were RTLS, and the only reason I was aware of that the crew missions were drone ship landings was because the abort-friendly ascent profile couldn't do RTLS. Quote Link to comment Share on other sites More sharing options...
zolotiyeruki Posted December 3, 2020 Share Posted December 3, 2020 Is there a substantial difference in apogee between RTLS vs droneship? Regardless, I suspect it's an issue of entry angle--RTLS comes nearly straight down, while ASDS landings come in at a much shallower angle, leaving more time to aerobrake before hitting the denser atmosphere. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 3, 2020 Share Posted December 3, 2020 17 minutes ago, Geonovast said: It is odd though, since AFAIK all previous CRS missions were RTLS, and the only reason I was aware of that the crew missions were drone ship landings was because the abort-friendly ascent profile couldn't do RTLS. Dragon 2 is much heavier than Dragon 1, so it must tip the scales enough to make a droneship landing necessary. Quote Link to comment Share on other sites More sharing options...
RCgothic Posted December 3, 2020 Share Posted December 3, 2020 (edited) Dragon 2 masses about 15.6t with full payload, which is about Falcon 9's max payload with recovery (and max payload full stop until someone pays to upgrade the PAF). Dragon 1 massed about 10.2t, so there's a pretty huge difference. Edited December 3, 2020 by RCgothic Quote Link to comment Share on other sites More sharing options...
YNM Posted December 4, 2020 Share Posted December 4, 2020 5 hours ago, sevenperforce said: It will have the same forward adapter, though. So IDA, not CBM ? How would you (say) get Starliner demo to dock if there're both Crew Dragon and Cargo Dragon occupying all the IDA ports ? I get that IDA adapters are smaller, and using CBM isn't possible if they want to keep the thrusters just off the docking port, but perhaps someone might need to make a good schedule out of them - or maybe we can put on a CBM-IDA adapter on the station... Quote Link to comment Share on other sites More sharing options...
cubinator Posted December 4, 2020 Share Posted December 4, 2020 1 hour ago, YNM said: So IDA, not CBM ? How would you (say) get Starliner demo to dock if there're both Crew Dragon and Cargo Dragon occupying all the IDA ports ? I get that IDA adapters are smaller, and using CBM isn't possible if they want to keep the thrusters just off the docking port, but perhaps someone might need to make a good schedule out of them - or maybe we can put on a CBM-IDA adapter on the station... I think there's a third one off the side of Node 3 - they could maybe move it to the nadir port on Node 2 with the Canadarm. Quote Link to comment Share on other sites More sharing options...
YNM Posted December 4, 2020 Share Posted December 4, 2020 (edited) 31 minutes ago, cubinator said: I think there's a third one off the side of Node 3 - they could maybe move it to the nadir port on Node 2 with the Canadarm. The current IDA adapters only fit to existing APAS docking ports, of which there has always been 2 available for docking (the 3rd one is used to permanently connect USOS and ROS). That means there're only 2 IDA docking ports available on ISS as of right now. Adding a 3rd one would be converting the larger CBM to IDA - essentially yet another PMA. Edited December 4, 2020 by YNM Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted December 4, 2020 Share Posted December 4, 2020 (edited) And Boeing had officially declared several years ago that they'll use another APAS-derived standard (according to the description, IDSS rev. B-like), incompatible to the currently used (IDSS rev. C/E-like). So, it's very interesting to see, which one will replace his docking adaptor with the opponent's one, who is the chicken. *** CBM is not for crewed ships docking. It's totally for berthing of either modules delivered by shuttle and attached by the manually operated arm, or for single-use cargo ships to be caught and attached with similar arm (because unlike the docking adaptor, it has it active, reusable, side on the station, while the ship is equipped with a simple and cheap passive ring to be burnt in air without any regret). Edited December 4, 2020 by kerbiloid Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 4, 2020 Share Posted December 4, 2020 Quote Link to comment Share on other sites More sharing options...
YNM Posted December 4, 2020 Share Posted December 4, 2020 1 hour ago, kerbiloid said: CBM is not for crewed ships docking. It's totally for berthing of either modules delivered by shuttle and attached by the manually operated arm, or for single-use cargo ships to be caught and attached with similar arm Well, Cargo Dragon is unmanned, so using CBM and the arm would've been fine, operations-wise. I could see that this might not be foreseen by SpaceX (or they simply won't even consider it), their new design only considers docking rather than berthing. For instance, I question any part of the trunk or the capsule can be fitted with Canadarm grapple fixture for both Crew Dragon and Cargo Dragon. Quote Link to comment Share on other sites More sharing options...
magnemoe Posted December 4, 2020 Share Posted December 4, 2020 13 hours ago, RealKerbal3x said: Wouldn't an RTLS have lower entry velocity and therefore put less stress on the booster? Also, recovery operations are much easier with RTLS as they don't have to operate out at sea. Think the RTLS is coming far more straight down giving higher g forces and more thermal load during reentry. As other point out dragon 2 is heavier too. Quote Link to comment Share on other sites More sharing options...
Delta dart Posted December 4, 2020 Share Posted December 4, 2020 Has anyone made a diagram of what SH 1 will look like because I saw one one google a while ago and now I can't find it and I would like to maybe see it again. Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 4, 2020 Share Posted December 4, 2020 Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 5, 2020 Share Posted December 5, 2020 New road closures, matching up with the TFR for Sunday: https://www.cameroncounty.us/spacex/ Quote Link to comment Share on other sites More sharing options...
Flavio hc16 Posted December 5, 2020 Share Posted December 5, 2020 55 minutes ago, RealKerbal3x said: New road closures, matching up with the TFR for Sunday: https://www.cameroncounty.us/spacex/ Sunday's closure is shorter, imho we will see a full dress rehersal with a pair of 3 engines-statc-fires, main and header tanks. Monday they'll try the "moonshot" Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 5, 2020 Share Posted December 5, 2020 30 minutes ago, Flavio hc16 said: Sunday's closure is shorter, imho we will see a full dress rehersal with a pair of 3 engines-statc-fires, main and header tanks. Monday they'll try the "moonshot" But why would they need an unlimited-altitude TFR for static fire testing? Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted December 5, 2020 Share Posted December 5, 2020 They have measured the distance to the monolith in Utah after the previous test. Quote Link to comment Share on other sites More sharing options...
munlander1 Posted December 5, 2020 Share Posted December 5, 2020 I just woke up and found out about the launch that was supposed to happen today. Then I heard about the scrub but not quick enough to avoid getting excited Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 6, 2020 Share Posted December 6, 2020 Quote Link to comment Share on other sites More sharing options...
RealKerbal3x Posted December 6, 2020 Share Posted December 6, 2020 Quote Link to comment Share on other sites More sharing options...
cubinator Posted December 6, 2020 Share Posted December 6, 2020 Music! Quote Link to comment Share on other sites More sharing options...
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