With the recent Soyuz mishap, an expected EVA at ISS to install batteries delivered by HTV may not happen soon. If the old batteries can't be placed in the HTV battery carrier before it leaves prior to the next cargo Dragon, can the HTV battery carrier be removed and stored, then installed ad hoc in cargo Dragon's trunk for removal/disposal of the batteries?
concerns about issues with the Dragon’s parachute system, citing anomalies during testing of the Crew Dragon spacecraft and unspecified problems with cargo versions of the Dragon.
https://spacenews.com/safety-panel-fears-soyuz-failure-could-exacerbate-commercial-crew-safety-concerns/Quoteconcerns about issues with the Dragon’s parachute system, citing anomalies during testing of the Crew Dragon spacecraft and unspecified problems with cargo versions of the Dragon.Does anyone know what anomalies / problems there have been?
How many flights have the new COPV's had? Have they flown them yet?
Quote from: HarryM on 10/12/2018 04:52 pmHow many flights have the new COPV's had? Have they flown them yet?As far as I know, core 51 - scheduled to fly the DM-1 mission - is the first time the COPV 2.0 will be flown.
Btw.. Dragon-1 Parachute Recovery more or less correspond to the positions of my map records. But what does not correspond at all is CRS-4 Recovery - where the reported distance 235nm from Port would be completely outside issued hazard area between 261-605nm from Port.Note also, that record of Payload Fairing Recovery approx.425nm from Shore is really very rough.SES-10 and BulgariaSat-1 missions are ok, but...Intelsat-35e fairing recovery as expendable flight should be even theoretically a bit further than GTO missions with ASDS booster recovery - 488nm according to fairing boot MarineTrafic positionNROL-76 has to be wrong, because it had hazard area only until 245nm downrange - LEO mission with RTLS booster landing.
The breakthrough referenced by Goldstein involved the addition of a Star 48 "kick stage" to the Falcon Heavy rocket, which would provide an extra boost of energy after the rocket's upper stage had fired. With this solid rocket motor kick stage, Goldstein said Clipper would need just a single Earth gravity assist and would not have to go into the inner Solar System for a Venus flyby."Nobody is saying we're not going on the SLS," Goldstein said. "But if by chance we don't, we don't have the challenge of the inner Solar System. This was a major development. This was a big deal for us."
Sen. Shelby is going to need a bigger fire hose to put out all these grass fires.From the Ars articleQuoteThe breakthrough referenced by Goldstein involved the addition of a Star 48 "kick stage" to the Falcon Heavy rocket, which would provide an extra boost of energy after the rocket's upper stage had fired. With this solid rocket motor kick stage, Goldstein said Clipper would need just a single Earth gravity assist and would not have to go into the inner Solar System for a Venus flyby."Nobody is saying we're not going on the SLS," Goldstein said. "But if by chance we don't, we don't have the challenge of the inner Solar System. This was a major development. This was a big deal for us."
From the Ars articleQuoteThe breakthrough referenced by Goldstein involved the addition of a Star 48 "kick stage" to the Falcon Heavy rocket, which would provide an extra boost of energy after the rocket's upper stage had fired. With this solid rocket motor kick stage, Goldstein said Clipper would need just a single Earth gravity assist and would not have to go into the inner Solar System for a Venus flyby."Nobody is saying we're not going on the SLS," Goldstein said. "But if by chance we don't, we don't have the challenge of the inner Solar System. This was a major development. This was a big deal for us."
Quote from: docmordrid on 12/04/2018 10:40 amFrom the Ars articleQuoteThe breakthrough referenced by Goldstein involved the addition of a Star 48 "kick stage" to the Falcon Heavy rocket, which would provide an extra boost of energy after the rocket's upper stage had fired. With this solid rocket motor kick stage, Goldstein said Clipper would need just a single Earth gravity assist and would not have to go into the inner Solar System for a Venus flyby."Nobody is saying we're not going on the SLS," Goldstein said. "But if by chance we don't, we don't have the challenge of the inner Solar System. This was a major development. This was a big deal for us."A Star-48 only adds a tiny bit of performance, so a Falcon Heavy alone could almost do the job.A Star 48 has about 2114 kg mass, about 114 kg when done. So assuming Clipper is 6 tonnes, as quoted, then at an ISP of 287, the Star-48 supplies 287*9.8*ln(8/6) = 809 m/s.But the second stage performance is reduced by needing to boost the extra mass of the Star. Assume that with no Star-48, the stack starts at 117t and ends at 11t. But with the Star, it starts at 119t and ends at 13t. At an ISP of 348, the extra mass then loses 348*9.8*(ln(117/11) - ln(119/13)) = 511 m/s. So the net gain is only 809-511 = 298 m/s.This is a pretty small faction of the 8000 m/s or so the second stage provides. It's on the order of what a burn-to-depletion could provide, as opposed to a controlled shutdown. But of course with a zillion dollar probe, they want to be sure they have the performance they need, not that it's merely likely.