I'm puzzled by SpaceX's decision to expend this booster. We know from previous Iridium flights that the vehicle has enough performance for it to be recovered. If I had an excess of obsolete boosters, I wouldn't expend them on missions where they can be reused, like in this flight. I would save them for those missions where they have to be expended, like in high performance GTO missions.
Quote from: Steven Pietrobon on 12/20/2017 04:17 amI'm puzzled by SpaceX's decision to expend this booster. We know from previous Iridium flights that the vehicle has enough performance for it to be recovered. If I had an excess of obsolete boosters, I wouldn't expend them on missions where they can be reused, like in this flight. I would save them for those missions where they have to be expended, like in high performance GTO missions.Not really. There are costs associated with supporting an older model of booster and this one likely has maybe one more mission left in it. Given they have to build block V for commercial crew and given the likely limited storage, over supply of boosters and likely greater cost to refurbish getting rid of block III makes sense.
Quote from: edkyle99 on 12/19/2017 07:25 pmExpend the booster to save money. Hmmmm. - Ed KyleIt's disappointing to me but how is expending a booster you plan to never use again confusing to people? I'd prefer they recover it and analyze/recycle it. But they didn't ask me.
Expend the booster to save money. Hmmmm. - Ed Kyle
A reusable booster is always going to fly as expendable on its last flight, no matter how long or short its flight history. It will keep happening until some financial penalty is applied for dropping this specific type of industrial waste in the ocean. Until then even a tiny cost to return the booster is greater than zero cost of letting it drop.
My guess is that, if the reason is performance-based, we need to look for this mission to have a lot higher-energy insertion orbit for some reason.
Quote from: chalz on 12/20/2017 10:45 amA reusable booster is always going to fly as expendable on its last flight, no matter how long or short its flight history. It will keep happening until some financial penalty is applied for dropping this specific type of industrial waste in the ocean. Until then even a tiny cost to return the booster is greater than zero cost of letting it drop.That depends on a lot of factors. It's quite possible that SpaceX will want to take units at the end of their fatigue life and cannibalise them for both scrap parts as well as rare alloys that can be returned to their suppliers for re-smelting and re-forging.
Quote from: AncientU on 12/19/2017 11:25 pmQuote from: edkyle99 on 12/19/2017 07:25 pmExpend the booster to save money. Hmmmm. - Ed KyleYou so want to be right about the folly of reusable boosters... but you're not.I've never called it "folly". They may well be on a path to making partial reuse pay, eventually, but what I have been saying is that they are not there yet. Throwing away a first stage on purpose during only its second flight (both lower energy LEO missions, BTW) is proof. - Ed Kyle
Quote from: edkyle99 on 12/19/2017 07:25 pmExpend the booster to save money. Hmmmm. - Ed KyleYou so want to be right about the folly of reusable boosters... but you're not.
Quote from: edkyle99 on 12/20/2017 01:03 amQuote from: AncientU on 12/19/2017 11:25 pmQuote from: edkyle99 on 12/19/2017 07:25 pmExpend the booster to save money. Hmmmm. - Ed KyleYou so want to be right about the folly of reusable boosters... but you're not.I've never called it "folly". They may well be on a path to making partial reuse pay, eventually, but what I have been saying is that they are not there yet. Throwing away a first stage on purpose during only its second flight (both lower energy LEO missions, BTW) is proof. - Ed KyleThis will be its third flight. Also, this is a polar orbit, on the higher end of LEO energies.
Quote from: sevenperforce on 12/20/2017 12:37 pmThis will be its third flight. Also, this is a polar orbit, on the higher end of LEO energies.Third?
This will be its third flight. Also, this is a polar orbit, on the higher end of LEO energies.
So why not give Iridium the most boost possible.