That would seem to make sense as there's no inter-dependency loop such as when you have a turbine energized by a gas generator fed by a pump powered by the turbine. Not only is an electric pump startup significantly simplified over a GG-based pump, the electric motor can generate higher torque at lower RPM than a gas turbine with equivalent power output in its primary operating range.
Quote from: msat on 02/05/2018 09:52 pmThat would seem to make sense as there's no inter-dependency loop such as when you have a turbine energized by a gas generator fed by a pump powered by the turbine. Not only is an electric pump startup significantly simplified over a GG-based pump, the electric motor can generate higher torque at lower RPM than a gas turbine with equivalent power output in its primary operating range.I'm not sure about the torque part being important, but it does seem like the startup sequence is simplified relative to GG and other cycles, due to the GG needing to supply its own fuel/oxidizer as well as provide the correct startup conditions for the main combustion chamber. Pretty sure ignition in the main combustion chamber needs to be very fuel rich to avoid a hard start.My understanding from following the AJ-10/BE-4 progress is that developing the startup sequence is extremely sensitive and there can be RUDs.
Quote from: Space Ghost 1962 on 02/04/2018 06:36 pmKeep in mind also that the 3D printed engines likely have just enough material (plus margin) for the mission.I did see a comment that they are likely eroding as we can see sparks, which makes sense given the materials properties of 3D printing (likely tiny voids in the material that lead to hotspots on the surface in the combustion chamber?), but there too it seems like they would fab the engines with adequate burn time to fully consume the propellant, so also not a barrier to a ~3 burn mission.
Keep in mind also that the 3D printed engines likely have just enough material (plus margin) for the mission.
One other consideration - running the turbo dry/tail off. If you sense the motor current load and if the sump is dry. you can cut/reverse current, and get a precision burn down to the last drop, without fear of turbo blowing (if you new/inferred turbo pressure, you could even stretch a marginal/failing one by accepting an lesser iSP and compensating in the GNC too).
Rocket Lab completes fit check for NASA VCLS ELaNa XIX missionEarly this month, Rocket Lab performed a successful fit check of the CubeSat dispensers for the NASA Venture Class Launch Service flight of the CubeSat Launch Initiative Educational Launch of Nanosatellites (ELaNa) XIX mission. The fit check was carried out at Rocket Lab’s Huntington Beach payload integration cleanroom.Venture Class launches aim to provide dedicated launches for CubeSats that would normally fly as secondary payloads, enabling these science missions to get exactly where they need to go on orbit.The fit check was performed between a Rocket Lab Electron Payload Plate - the interface between Electron and the payloads - and a series of Tyvak Nano-Satellite Systems and Planetary Systems Corporation dispensers. Teams from Tyvak and Rocket Lab participated in the fit check.Fit checks provide valuable risk reduction in payload integration by verifying physical interfaces and allowing for a dry run of installation procedures prior to the launch campaign.The Huntington Beach Payload Integration Cleanroom is a Class 100k cleanroom located in our Rocket Lab USA Headquarters. This cleanroom is used for payloads that are processed in the United States before being shipped to their final launch site, such as Launch Complex 1 in Mahia, New Zealand. The facility will be used for the processing of the NASA ELaNa XIX payloads, which will be integrated to their dispensers in the United States before shipment to the launch site later this year for installation on Electron.The Electron Payload Plate is a customizable interface which can support a variety of CubeSat and Microsatellite dispensers and separation systems. The Payload Plate can be entirely removed from Electron, allowing for integration to occur away from the launch site, such as in our Huntington Beach cleanroom or at a remote customer facility. Rocket Lab can accommodate both single and multipayload configurations on the plate.The target launch date for the NASA Venture Class Launch Service ELaNa XIX mission is yet to be announced. The launch will see the following CubeSats deployed:CubeSat: AndesiteOrganization: Boston UniversityCubeSat: CeresOrganization: NASA Goddard Spaceflight CenterCubeSat: STF-1Organization: NASA Goddard Spaceflight CenterCubeSat: CubeSailOrganization: University of Illinois at Urbana-ChampaignCubeSat: CHOMPTTOrganization: University of FloridaCubeSat: NMTSatOrganization: New Mexico Institute of Mining and TechnologyCubeSat: DaVinciOrganization: North Idaho STEM Charter AcademyCubeSat: RsatOrganization: U. S. Naval AcademyCubeSat: ISXOrganization: California Polytechnic State UniversityCubeSat: Shields-1Organization: NASA Langley Research CenterCubeSat: ALBusOrganization: NASA Glenn Research CenterCubeSat: SHFT-1Organization: NASA JPL
Quote from: ArbitraryConstant on 02/04/2018 06:46 pmQuote from: Space Ghost 1962 on 02/04/2018 06:36 pmKeep in mind also that the 3D printed engines likely have just enough material (plus margin) for the mission.I did see a comment that they are likely eroding as we can see sparks, which makes sense given the materials properties of 3D printing (likely tiny voids in the material that lead to hotspots on the surface in the combustion chamber?), but there too it seems like they would fab the engines with adequate burn time to fully consume the propellant, so also not a barrier to a ~3 burn mission.I wonder if this bug could be turned into a feature: if the sintered powder is already going to ablate into small particles, sinter the inner nozzle liner out of a propellant metal, e.g. Aluminium, Beryllium, Boron, etc. As long as the particle size is small enough for most combustion to occur while within the nozzle bell, it will be a net contributor to thrust, and without the particulate issues of having it incorporated into the fuel itself.
A great stage one stack test completed for our upcoming third flight. Nine #Rutherford engines firing in sync is a thing of beauty.
QuoteRocket Lab completes fit check for NASA VCLS ELaNa XIX missionEarly this month, Rocket Lab performed a successful fit check of the CubeSat dispensers for the NASA Venture Class Launch Service flight of the CubeSat Launch Initiative Educational Launch of Nanosatellites (ELaNa) XIX mission. The fit check was carried out at Rocket Lab’s Huntington Beach payload integration cleanroom.Venture Class launches aim to provide dedicated launches for CubeSats that would normally fly as secondary payloads, enabling these science missions to get exactly where they need to go on orbit.The fit check was performed between a Rocket Lab Electron Payload Plate - the interface between Electron and the payloads - and a series of Tyvak Nano-Satellite Systems and Planetary Systems Corporation dispensers. Teams from Tyvak and Rocket Lab participated in the fit check.Fit checks provide valuable risk reduction in payload integration by verifying physical interfaces and allowing for a dry run of installation procedures prior to the launch campaign.The Huntington Beach Payload Integration Cleanroom is a Class 100k cleanroom located in our Rocket Lab USA Headquarters. This cleanroom is used for payloads that are processed in the United States before being shipped to their final launch site, such as Launch Complex 1 in Mahia, New Zealand. The facility will be used for the processing of the NASA ELaNa XIX payloads, which will be integrated to their dispensers in the United States before shipment to the launch site later this year for installation on Electron.The Electron Payload Plate is a customizable interface which can support a variety of CubeSat and Microsatellite dispensers and separation systems. The Payload Plate can be entirely removed from Electron, allowing for integration to occur away from the launch site, such as in our Huntington Beach cleanroom or at a remote customer facility. Rocket Lab can accommodate both single and multipayload configurations on the plate.The target launch date for the NASA Venture Class Launch Service ELaNa XIX mission is yet to be announced. The launch will see the following CubeSats deployed:CubeSat: AndesiteOrganization: Boston UniversityCubeSat: CeresOrganization: NASA Goddard Spaceflight CenterCubeSat: STF-1Organization: NASA Goddard Spaceflight CenterCubeSat: CubeSailOrganization: University of Illinois at Urbana-ChampaignCubeSat: CHOMPTTOrganization: University of FloridaCubeSat: NMTSatOrganization: New Mexico Institute of Mining and TechnologyCubeSat: DaVinciOrganization: North Idaho STEM Charter AcademyCubeSat: RsatOrganization: U. S. Naval AcademyCubeSat: ISXOrganization: California Polytechnic State UniversityCubeSat: Shields-1Organization: NASA Langley Research CenterCubeSat: ALBusOrganization: NASA Glenn Research CenterCubeSat: SHFT-1Organization: NASA JPLhttps://www.rocketlabusa.com/news/updates/rocket-lab-completes-fit-check-for-nasa-vcls-elana-xix-mission/
Rocket Lab says smouldering battery problem fixed 26 Feb, 2018 11:37amRocket Lab says it has found the reason a battery overheated on its assembly line and has put corrective measures in place.Firefighters were called to the company last night after the manufacturing area was affected by smoke from the lithium battery.
http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=12002151
There doesn't seem to be a thread for Rocket Lab's launch today. Not here nor in the live event section. Latest I heard said it was today.Just three more hours left, assuming "march 1st" is in NZ time. Should I assume the launch has been postponed?
Celebrating #InternationalWomensDay2018 with some of our rocket women. All industries, including ours, are stronger with more women in STEM careers. To all the young women dreaming of becoming scientists and engineers, we're with you. Dream big and do it!
QuoteCelebrating #InternationalWomensDay2018 with some of our rocket women. All industries, including ours, are stronger with more women in STEM careers. To all the young women dreaming of becoming scientists and engineers, we're with you. Dream big and do it!https://twitter.com/rocketlab/status/971584938163060736?s=21Note NASA logo on hardware in background.
Meet Maxwell, our in-house designed and built cubesat dispenser. Available in 1U, 3U and 6U form factors (or larger on request). These are some of the lightest dispensers on the market. Visit us at Satellite 2018 tomorrow to see them. #Maxwell #SATShow