Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?
Quote from: Klebiano on 06/04/2019 02:55 amQuote from: b0objunior on 06/02/2019 04:32 amQuote from: Robotbeat on 06/02/2019 04:27 amQuote from: Klebiano on 06/02/2019 04:24 amThe valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?They could be servo motors with a NEMA like casing.I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.How much mass are they?Not much, for example, a NEMA 34 can weight 5kg, but I think that the problem is not the weight, it's the environment that these motors have to withstand.There are 6 of them, so 30kg. That makes a significant different to the engine’s thrust to weight. I suspect a different form factor would halve the mass; I think these are just for the prototype.
Quote from: b0objunior on 06/02/2019 04:32 amQuote from: Robotbeat on 06/02/2019 04:27 amQuote from: Klebiano on 06/02/2019 04:24 amThe valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?They could be servo motors with a NEMA like casing.I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.How much mass are they?Not much, for example, a NEMA 34 can weight 5kg, but I think that the problem is not the weight, it's the environment that these motors have to withstand.
Quote from: Robotbeat on 06/02/2019 04:27 amQuote from: Klebiano on 06/02/2019 04:24 amThe valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?They could be servo motors with a NEMA like casing.I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.How much mass are they?
Quote from: Klebiano on 06/02/2019 04:24 amThe valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?They could be servo motors with a NEMA like casing.I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
Quote from: b0objunior on 05/17/2019 10:20 pmQuestion, from what we know of the BE-7, does it seems like a good transfer vehicle engine?I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode. That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Quote from: daveklingler on 07/23/2019 11:51 pmQuote from: b0objunior on 05/17/2019 10:20 pmQuestion, from what we know of the BE-7, does it seems like a good transfer vehicle engine?I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode. That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine. Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.
Quote from: TrevorMonty on 07/24/2019 12:09 amQuote from: daveklingler on 07/23/2019 11:51 pmQuote from: b0objunior on 05/17/2019 10:20 pmQuestion, from what we know of the BE-7, does it seems like a good transfer vehicle engine?I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode. That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine. Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.Which I guess they plan to handle with fuel cell-powered IVF. I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.
Quote from: daveklingler on 07/24/2019 01:22 amQuote from: TrevorMonty on 07/24/2019 12:09 amQuote from: daveklingler on 07/23/2019 11:51 pmQuote from: b0objunior on 05/17/2019 10:20 pmQuestion, from what we know of the BE-7, does it seems like a good transfer vehicle engine?I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode. That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine. Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.Which I guess they plan to handle with fuel cell-powered IVF. I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.I'm not sure what you mean by bypass. Sorry, I not really good with rocket engines language.
Quote from: b0objunior on 07/24/2019 06:26 amQuote from: daveklingler on 07/24/2019 01:22 amQuote from: TrevorMonty on 07/24/2019 12:09 amQuote from: daveklingler on 07/23/2019 11:51 pmQuote from: b0objunior on 05/17/2019 10:20 pmQuestion, from what we know of the BE-7, does it seems like a good transfer vehicle engine?I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode. That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine. Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.Which I guess they plan to handle with fuel cell-powered IVF. I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.I'm not sure what you mean by bypass. Sorry, I not really good with rocket engines language.With some expander cycle engines like RL10 family and BE-7 there is a bypass valve and line used during prestart to spin up the turbopumps and the ignition process. The BPV is closed upon start.
Bezos: Now have 13 minutes of test time on the BE-7 engine.
AFRL AND BLUE ORIGIN PARTNER ON TEST SITE FOR BE-7 LUNAR LANDER ENGINE DEVELOPMENTEDWARDS AIR FORCE BASE, Calif. – The Air Force Research Laboratory and Blue Origin are developing a new test facility for the Blue Origin BE-7 lunar lander engine at the AFRL rocket lab here.Capital improvements, funded by Blue Origin, will allow BE-7 testing in a simulated space-like environment. Planned work includes adding liquid hydrogen (LH2) and liquid oxygen (LOX) propellant capabilities, along with other facility upgrades.AFRL and Blue Origin signed a 15-year Cooperative Research and Development Agreement Dec. 11, 2019 to develop a test facility for the Blue Origin BE-7 Lunar Lander Engine here. The CRADA was signed by Dr. Shawn Phillips, chief of the Rocket Propulsion Division, and Bob Smith, CEO of Blue Origin.The BE-7 engine is a new, high performance 10,000 pound-thrust dual-expander cycle engine for in-space applications, including Blue Origin’s Blue Moon lunar lander. The new AFRL test capabilities will support various development, qualification, and production acceptance tests of the BE-7 engine under future Commercial Test Agreements, also to be funded by Blue Origin.The CRADA focuses on a public-private partnership to create a superior upper stage engine and in-space propulsion testing capability that directly supports near-term national space objectives, and provides enduring infrastructure to support current and future national security and commercial space requirements.“We are thrilled to partner with the AFRL Aerospace Systems Directorate and their Rocket Propulsion Division at Edwards Air Force Base,” said Eric Blumer, Senior Director for the BE-7 engine program. “Repurposing the infrastructure at the 1-42 test site enables us to accelerate development of the BE-7 engine for our Blue Moon lunar lander. It will play a critical role in Blue Origin’s support of the Artemis program to send women and men to the moon by 2024. Dr. Phillips and his team were very responsive as we defined this unique CRADA.”“The AFRL team is excited to collaborate with Blue Origin and support the U.S. presence in space,” said Dr. Dan Brown, chief engineer of the AFRL Rocket Lab. “Many of our engineers view this effort as a natural extension of AFRL’s early development of the F-1 engine in the 1950s that ultimately took humans to the moon on the Saturn V.”“Facility improvements under this public private partnership will open the door for rocket engine testing beyond the BE-7 test campaigns. The new test capability enables the Air Force and future commercial partners to test advanced upper stage engines at relevant altitude conditions.”The AFRL Rocket Lab at Edwards Air Force Base, California has played a key role in advancing rocket engine technologies for the nation, since 1952. AFRL has been a prominent player in nearly every liquid rocket engine developed and flown by the United States.Blue Origin was founded by Jeff Bezos, the founder and CEO of Amazon, in 2000 with the mission to “enable an enduring human presence in space.” The company has focused on developing operationally reusable launch systems and technologies to dramatically lower the cost to access space with greatly increased safety and reliability. Blue Origin has a development facility in Kent, Washington, as well as facilities in Texas, Florida, and Alabama where they test rocket engines and conduct launch operations.
The Altitude facility at Edwards Air Force Base, California, does tactical scale research on next generation rocket motor and engine components, propellant formulations, and subsystems; and high vacuum research on satellite components, subsystems, and systems. Research testing includes solid rocket motor testing at simulated altitudes up to 120,000 feet. The complex has been used for space simulation to validate thrust vector control systems, baseline a standard for solid rocket motor propellants, research extendible nozzle cones, and systems, and research space qualified ignition systems. (Courtesy photo)
Isn't there already a vacuum facility where the RL10 is tested? Can they not use that?
...the BE-7 will be tested at an Air Force Research Laboratory (AFRL) facility at Edwards Air Force Base in California....Though testing the BE-7 is the primary purpose of these upgrades, the newly improved facility also will be used to test other pieces of hardware and engines. "Blue Origin does plan to 'piggyback' parts of the lander that interface to the BE-7 engine to reduce vehicle integration risks and mature the vehicle parts with engine interfaces along with the engine," he said. In other words, some of the pieces that will be tested at this facility, other than the BE-7, will be parts of the lander itself that will join with the lander's engine.
The BE-7 engine started hot firing in the summer of 2019 and is currently in test at NASA Marshall Spaceflight Center in partnership with NASA. In total, BE-7 has accrued more than 13 minutes of total test time (more than 780 seconds) on multiple test articles with the most for any single test article being up to 3-minutes of continuous test time.
Isp of 453 s doesn't sound impressive. So the main catch is the deep throttling? Or is there some other advantageous thing to this engine?
There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines
Quote from: ncb1397 on 06/21/2020 09:03 pmThere are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_enginesTrue but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.
Quote from: Aeneas on 06/21/2020 09:40 pmQuote from: ncb1397 on 06/21/2020 09:03 pmThere are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_enginesTrue but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.Lower dry mass is more important than few seconds ISP. This especially so in case of reuseable lander or OTV where every kg makes a difference.