Quote from: johnlandish on 05/29/2018 10:48 pm"but our BE-3U engine, which is the upper-stage variant of our liquid hydrogen engine, made such fast progress that we decided to flip that second stage to hydrogen. Then the two-stage vehicle gets vastly improved performance." - Jeff Bezos on using two BE-3U's instead of one BE-4U. Source: Jeff Bezos: ‘We will have to leave this planet … and it’s going to make this planet better’
"but our BE-3U engine, which is the upper-stage variant of our liquid hydrogen engine, made such fast progress that we decided to flip that second stage to hydrogen. Then the two-stage vehicle gets vastly improved performance." - Jeff Bezos on using two BE-3U's instead of one BE-4U.
Whoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.
Quote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Not sure when the decision was made, but on March 29, 2018, SpaceNews broke the story about Blue Origin having changed its plans for New Glenn's second stage to the 2xBE-3U configuration. - Ed Kyle
Source: Jeff Bezos: ‘We will have to leave this planet … and it’s going to make this planet better’
Quote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Perhaps because BE-4 development is taking longer than they originally planned. So it makes sense to concentrate on just the normal BE-4 and use the BE-3U since it is low hanging fruit and will work better for lunar purposes anyway.
Quote from: Lars-J on 05/30/2018 04:41 amQuote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Perhaps because BE-4 development is taking longer than they originally planned. So it makes sense to concentrate on just the normal BE-4 and use the BE-3U since it is low hanging fruit and will work better for lunar purposes anyway.Do you think they'll use the 2 stage variant for lunar missions? They were already planning a third stage with a single BE-3U for BEO missions.
Quote from: edkyle99 on 05/30/2018 01:59 amQuote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Not sure when the decision was made, but on March 29, 2018, SpaceNews broke the story about Blue Origin having changed its plans for New Glenn's second stage to the 2xBE-3U configuration. - Ed Kyle The decision to change the S2 architecture was made several months before SN broke the news in late March. What I'm hearing is that is was basically a done deal late last year.
Jeff says they bought the boat for landing NG and are refitting it? Sounds like our marine sleuths over in the SpaceX ASDS threads ought to be given a heads up for a new hunting target...
Quote from: Prettz on 05/30/2018 01:37 pmQuote from: Lars-J on 05/30/2018 04:41 amQuote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Perhaps because BE-4 development is taking longer than they originally planned. So it makes sense to concentrate on just the normal BE-4 and use the BE-3U since it is low hanging fruit and will work better for lunar purposes anyway.Do you think they'll use the 2 stage variant for lunar missions? They were already planning a third stage with a single BE-3U for BEO missions.With the higher ISP and much smaller engines they may not need a third stage for high energy missions. If anything it might hurt LEO performance similar to the SEC on ULA rockets, but mass to LEO may not be a priority if their core markets are planetary, GEO and volume-centric constellation deployments.
Quote from: Llian Rhydderch on 05/26/2018 01:29 amSo, let's get public sources: What do we know about any people's names on the Blue Origin team? What do we know about who their former employers were? for which years? Who, from all of Kistler's people are not working, at Blue Origin today? How many ever joined Blue from Kistler? At what levels of responsibility? When? What evidence do we have that any persons who formerly were employed by Kistler are playing the major directional role at Blue?For starters Rob Meyerson.
So, let's get public sources: What do we know about any people's names on the Blue Origin team? What do we know about who their former employers were? for which years? Who, from all of Kistler's people are not working, at Blue Origin today? How many ever joined Blue from Kistler? At what levels of responsibility? When? What evidence do we have that any persons who formerly were employed by Kistler are playing the major directional role at Blue?
Quote from: intrepidpursuit on 05/30/2018 02:31 pmQuote from: Prettz on 05/30/2018 01:37 pmQuote from: Lars-J on 05/30/2018 04:41 amQuote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Perhaps because BE-4 development is taking longer than they originally planned. So it makes sense to concentrate on just the normal BE-4 and use the BE-3U since it is low hanging fruit and will work better for lunar purposes anyway.Do you think they'll use the 2 stage variant for lunar missions? They were already planning a third stage with a single BE-3U for BEO missions.With the higher ISP and much smaller engines they may not need a third stage for high energy missions. If anything it might hurt LEO performance similar to the SEC on ULA rockets, but mass to LEO may not be a priority if their core markets are planetary, GEO and volume-centric constellation deployments.LEO performance is likely to improve with LH2 upper, since BE-3U is quite high thrust at 585 kN. I'm estimating a 1150 tonne booster and 200 tonne upper stage, with payloads of around 55 tonnes to LEO, 21 tonnes to GTO, 6.5 tonnes to GEO, and 15 tonnes to TLI. All with only 2 stages and with booster downrange landing.The 3-stage version with a ~50 tonne upper stage and single BE-3U would get about 25 tonnes to TLI with booster reuse. About the same as SLS Block 1, despite having about half the liftoff mass and a reusable booster.My reasoning for the large upper stage is mainly due to the need to constrain staging velocity to limit heat load on the reentering booster, since Blue isn't planning to do extra burns to slow the booster down. Also, Blue's spokesman said they need to stretch the second stage for LH2, which implies a gross mass substantially larger than then 140 tonnes that would fit in the volume of the initial single BE-4U stage.
Quote from: envy887 on 05/30/2018 03:38 pmQuote from: intrepidpursuit on 05/30/2018 02:31 pmQuote from: Prettz on 05/30/2018 01:37 pmQuote from: Lars-J on 05/30/2018 04:41 amQuote from: intrepidpursuit on 05/30/2018 12:11 amWhoa. They've changed the entire architecture of the second stage this late in the game? I wonder when that decision was made.Perhaps because BE-4 development is taking longer than they originally planned. So it makes sense to concentrate on just the normal BE-4 and use the BE-3U since it is low hanging fruit and will work better for lunar purposes anyway.Do you think they'll use the 2 stage variant for lunar missions? They were already planning a third stage with a single BE-3U for BEO missions.With the higher ISP and much smaller engines they may not need a third stage for high energy missions. If anything it might hurt LEO performance similar to the SEC on ULA rockets, but mass to LEO may not be a priority if their core markets are planetary, GEO and volume-centric constellation deployments.LEO performance is likely to improve with LH2 upper, since BE-3U is quite high thrust at 585 kN. I'm estimating a 1150 tonne booster and 200 tonne upper stage, with payloads of around 55 tonnes to LEO, 21 tonnes to GTO, 6.5 tonnes to GEO, and 15 tonnes to TLI. All with only 2 stages and with booster downrange landing.The 3-stage version with a ~50 tonne upper stage and single BE-3U would get about 25 tonnes to TLI with booster reuse. About the same as SLS Block 1, despite having about half the liftoff mass and a reusable booster.My reasoning for the large upper stage is mainly due to the need to constrain staging velocity to limit heat load on the reentering booster, since Blue isn't planning to do extra burns to slow the booster down. Also, Blue's spokesman said they need to stretch the second stage for LH2, which implies a gross mass substantially larger than then 140 tonnes that would fit in the volume of the initial single BE-4U stage.The alternative to 3rd stage is reuseable OTV which 2 stage NG refuels. Mass of OTV can be very low as it doesn't need to handle launch forces.But it does require Blue to develop inorbit refuelling technology of LH and LOX. Something they will need to do eventually.
With the higher ISP and much smaller engines they may not need a third stage for high energy missions. If anything it might hurt LEO performance similar to the SEC on ULA rockets, but mass to LEO may not be a priority if their core markets are planetary, GEO and volume-centric constellation deployments.
It also requires transferring payloads between the 2nd stage and the OTV, which might be considerably more difficult than refueling, or at least require payloads to be explicitly designed to handle transfer. It might be simpler to just refuel the 2nd stage and send it wherever the payload needs to go. Somewhat like BFS.
Erika Wagner of Blue Origin notes at #DPSS18 that the company is now up to about 1,500 employees.