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#1300
by
speedevil
on 05 Feb, 2018 22:06
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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.
If you mean higher torque at lower RPM for the purposes of initial pumping, the load on the pump is some large factor (about ^3) of RPM, as RPM goes with pressure, and volume goes with RPM too.
This means that low RPM is basically irrelevant as the pump is almost free-spinning, and the primary load is inertia in the startup sequence.
If you mean you can optimise for a lower overall RPM than you might end up with as a 100kW output turbine of minimum weight as the source - perhaps.
To a moderate extent, more RPM means lighter motors per unit power as they tend to be torque limited per unit weight, meaning high RPM is good.
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#1301
by
msat
on 05 Feb, 2018 22:55
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Regardless of what the primary load might be on the motor/turbine at a given RPM, the greater the torque supplied to the pump during spin-up, the quicker it could get to its designated operating point (within structural and fluid dynamic limits, of course).
But I concede that the apparent quickness of the Rutherford power-up could simply be attributed to the scale of the engines verses those of the large orbital machines rather than the choice of turbopumps. Though as far as rotating machinery goes, I can't think of any of the regular prime movers that have the kind of acceleration so typically common in electric motors. Maybe it's both.. Or maybe neither.
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#1302
by
ArbitraryConstant
on 05 Feb, 2018 23:24
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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.
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 AR-1/BE-4 progress is that developing the startup sequence is extremely sensitive and there can be RUDs.
edit: fixed, thanks russianhalo117
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#1303
by
russianhalo117
on 06 Feb, 2018 00:56
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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.
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.
You mean AR-1 as AJ-10 first operational version dates back to 1957.
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#1304
by
edzieba
on 06 Feb, 2018 08:58
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Keep 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.
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#1305
by
john smith 19
on 07 Feb, 2018 21:48
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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).
Improving the precision of engine cut off can pay quite big dividends in terms of accuracy of the final orbit.
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#1306
by
FutureSpaceTourist
on 09 Feb, 2018 08:35
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Rocket Lab completes fit check for NASA VCLS ELaNa XIX mission
Early 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: Andesite
Organization: Boston University
CubeSat: Ceres
Organization: NASA Goddard Spaceflight Center
CubeSat: STF-1
Organization: NASA Goddard Spaceflight Center
CubeSat: CubeSail
Organization: University of Illinois at Urbana-Champaign
CubeSat: CHOMPTT
Organization: University of Florida
CubeSat: NMTSat
Organization: New Mexico Institute of Mining and Technology
CubeSat: DaVinci
Organization: North Idaho STEM Charter Academy
CubeSat: Rsat
Organization: U. S. Naval Academy
CubeSat: ISX
Organization: California Polytechnic State University
CubeSat: Shields-1
Organization: NASA Langley Research Center
CubeSat: ALBus
Organization: NASA Glenn Research Center
CubeSat: SHFT-1
Organization: NASA JPL
https://www.rocketlabusa.com/news/updates/rocket-lab-completes-fit-check-for-nasa-vcls-elana-xix-mission/
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#1307
by
Space Ghost 1962
on 09 Feb, 2018 20:04
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Keep 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.
Not a good idea.
Combustion is chaotic and not always as stoichiometric as one would like. So you could have a "burn through" or a velocity "accumulation clog" (byproduct) and the engine might behave nonlinearly/detonate. You want a predictable burn/reliable engine expectation of function.
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#1308
by
FutureSpaceTourist
on 19 Feb, 2018 06:16
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#1309
by
Lars-J
on 19 Feb, 2018 07:26
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Those tests appear to be with a shortened stage 1 tank. Do they just take off the whole engine structure and attach it as one piece to a flight vehicle for launch?
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#1310
by
john smith 19
on 19 Feb, 2018 12:04
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Rocket Lab completes fit check for NASA VCLS ELaNa XIX mission
Early 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: Andesite
Organization: Boston University
CubeSat: Ceres
Organization: NASA Goddard Spaceflight Center
CubeSat: STF-1
Organization: NASA Goddard Spaceflight Center
CubeSat: CubeSail
Organization: University of Illinois at Urbana-Champaign
CubeSat: CHOMPTT
Organization: University of Florida
CubeSat: NMTSat
Organization: New Mexico Institute of Mining and Technology
CubeSat: DaVinci
Organization: North Idaho STEM Charter Academy
CubeSat: Rsat
Organization: U. S. Naval Academy
CubeSat: ISX
Organization: California Polytechnic State University
CubeSat: Shields-1
Organization: NASA Langley Research Center
CubeSat: ALBus
Organization: NASA Glenn Research Center
CubeSat: SHFT-1
Organization: NASA JPL
https://www.rocketlabusa.com/news/updates/rocket-lab-completes-fit-check-for-nasa-vcls-elana-xix-mission/
That is quite a list.
I especially like the fact they could all be attached to the mounting plate "offline" and then the whole package is attached to the LV as a single unit.
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#1311
by
FutureSpaceTourist
on 26 Feb, 2018 18:19
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Rocket Lab says smouldering battery problem fixed
26 Feb, 2018 11:37am
Rocket 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
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#1312
by
john smith 19
on 28 Feb, 2018 23:23
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#1313
by
high road
on 01 Mar, 2018 06:56
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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?
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#1314
by
Kryten
on 01 Mar, 2018 07:03
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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?
All they actually said is the launch is in march-i.e. NET march 1st. There's no NOTAM up for it, so definitely not going tomorrow.
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#1315
by
high road
on 01 Mar, 2018 10:38
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Thx. Seeing the date everywhere made me think it was already confirmed. Another sign paperwork is harder than licking gravity :p
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#1316
by
FutureSpaceTourist
on 08 Mar, 2018 06:45
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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!
https://twitter.com/rocketlab/status/971584938163060736?s=21Note NASA logo on hardware in background.
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#1317
by
Andrew_W
on 08 Mar, 2018 17:26
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#1318
by
FutureSpaceTourist
on 11 Mar, 2018 20:43
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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
https://twitter.com/rocketlab/status/972922529718321152?s=21
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#1319
by
starbase
on 14 Mar, 2018 14:06
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Electron will launch two LEMUR-2s on the next launch in the coming weeks:
"Huntington Beach, California. March 13, 2018: US orbital launch provider Rocket Lab has today confirmed its next launch will be the company’s first fully commercial flight. Two Lemur-2 cubesats for launch customer Spire Global will be on board the upcoming launch, with the full manifest to be confirmed in coming weeks.
The flight’s name was put to a vote on social media, with “It’s Business Time” coming out as a clear fan favourite and a continuation of company’s previous flight names, “It’s a Test” and “Still Testing”.
Rocket Lab founder and CEO Peter Beck says “It’s Business Time” highlights Rocket Lab’s agile approach to responsive space. The launch has been manifested weeks out from launch, rather than the many months or years it can typically take under existing launch models.
“We came at the challenge of opening access to space from a new perspective. Building to tail numbers and tailoring a vehicle to the payload is a rigid and slow way of getting satellites on orbit. As the satellite industry continues to innovate at a break-neck pace and the demand for orbital infrastructure grows, we’re there with a production line of Electron vehicles ready to go and a private launch site licensed for flight every 72 hours. Launch will no longer be the bottleneck that slows innovation in space,” he says.
“We always set out to test a launch vehicle that was as close to production-ready as possible. To complete a test program so quickly and be flying commercial customers is a great feeling. It’s business time,” Mr Beck adds.
Rocket Lab’s third Electron vehicle will be shipped to Launch Complex 1 on New Zealand’s Māhia Peninsula in coming weeks, where final checkouts will be completed ahead of the “It’s Business Time” launch.
This year Rocket Lab is increasing its launch cadence and scaling up production of the Electron launch vehicle to meet a growing manifest. The company aims to produce 100 Rutherford engines in 2018 from its three-acre headquarters and production facility in Huntington Beach, California. More than 30 engines have already been completed and are undergoing integration onto Electron vehicles.
Rocket Lab’s first test launch, “It’s a Test,” was completed in May 2017, with the second test, “Still Testing,” taking place in January 2018. This flight successfully reached orbit, deployed commercial customer payloads for Planet and Spire Global and circularized an orbit using a previously unannounced kick stage."http://www.rocketlabusa.com/news/updates/its-business-time-at-rocket-lab/Source:
https://twitter.com/RocketLab/status/973706806055718912
