NASA issued an RFI today looking for industry input on a proposed deorbit module for the ISS to bring it down at the end of its life, something originally projected to be done by Progress cargo spacecraft. https://sam.gov/opp/74252cfe7d49416abae0977fe4fd503c/view
From a NASA statement: ISS partners “developed a strategy and action plan that evaluated the use of multiple Roscosmos Progress spacecraft to support deorbit operations. These studies indicated additional spacecraft may provide more robust capabilities for deorbit.”
Berger with the burnshttps://twitter.com/SciGuySpace/status/1560740178519621635
Quote from: russianhalo117 on 08/19/2022 11:28 pmQuote from: cohberg on 08/19/2022 10:41 pmBerger with the burnsThey have some flight capable TKS/MLM test articles lying around which could be converted to flight articles though they are trying to move away from outdated legacy Soviet heritage designs and hardware when possible.I think this is more about the thruster firings after docking that put the station into an uncontrolled spin rather than how long it took / will take to build equivalent hardware.
Quote from: cohberg on 08/19/2022 10:41 pmBerger with the burnsThey have some flight capable TKS/MLM test articles lying around which could be converted to flight articles though they are trying to move away from outdated legacy Soviet heritage designs and hardware when possible.
Berger with the burns
For 300ISP engine it will need 7.5t of fuel for 47ms DV required and engine of 3.3kn or 7klbs. This will need to be purpose built vehicle with SpaceX or NG being my pick given their excellent record servicing ISS.
Orion ESM carries 8.6 t of fuel.
Quote from: TrevorMonty on 08/20/2022 11:17 amFor 300ISP engine it will need 7.5t of fuel for 47ms DV required and engine of 3.3kn or 7klbs. This will need to be purpose built vehicle with SpaceX or NG being my pick given their excellent record servicing ISS.Either that, or I could imagine something derived from one of the many new space tugs, especially MEV and Photon. NG seems pretty open about collaboration, and they have a great platform to start with.My guess for an evaluation would be:1) Modified Cygnus2) MEV (+ Cygnus?)3) Cygnus + Photon4) Obligatory SpaceX bid with varying quality depending on their mood5) A happy mix of companies you've never heard of proposing ludicrous budgets or nonexistent spacecraft
Quote from: hektor on 08/20/2022 11:40 amOrion ESM carries 8.6 t of fuel.The engine is powerful enough maybe to powerful.
Nasa says in this RFI that, "The deorbit vehicle design and operations shall allow rendezvous and attach to the ISS at Node 2 Forward." So what must be the preference for docking mechanism, dock to CBM or an IDA?
H3 is designed to lift more than 7,900 kilograms to geosynchronous transfer orbit, Hyodo said. The rocket could, with an upgraded second stage, heft more than 3,400 kilograms of pressurized cargo and more than 1,000 kilograms of unpressurized cargo to the lunar Gateway space station using HTV-X, he said. Launching an HTV-X cargo vessel to the gateway would require two H3 launches, he said. The first launch would send an HTV-X into an orbit around the Earth, he said. The second launch would send up an upper stage with an enlarged fuel tank to dock with the HTV-X and propel it to the Gateway, he said. https://spacenews.com/mitsubishi-heavy-industries-mulls-upgraded-h3-rocket-variants-for-lunar-missions/
Quote from: niwax on 08/20/2022 11:54 amQuote from: TrevorMonty on 08/20/2022 11:17 amFor 300ISP engine it will need 7.5t of fuel for 47ms DV required and engine of 3.3kn or 7klbs. This will need to be purpose built vehicle with SpaceX or NG being my pick given their excellent record servicing ISS.Either that, or I could imagine something derived from one of the many new space tugs, especially MEV and Photon. NG seems pretty open about collaboration, and they have a great platform to start with.My guess for an evaluation would be:1) Modified Cygnus2) MEV (+ Cygnus?)3) Cygnus + Photon4) Obligatory SpaceX bid with varying quality depending on their mood5) A happy mix of companies you've never heard of proposing ludicrous budgets or nonexistent spacecraftPhoton is only 300kg. In saying that RL might make bid. They are more than capable enough of building electric pump engines powerful enough that use same fuel as Photon. Would give them OTV for Neutron.
I guess if you want to go crazy you could also forego the extra vehicle entirely and slap a docking port and some Dragon avionics on a Falcon second stage. That thing will arrive in LEO with 15 tons of fuel to spare and plenty of time to dock thanks to GEO capability.
Quote from: niwax on 08/22/2022 10:22 pmI guess if you want to go crazy you could also forego the extra vehicle entirely and slap a docking port and some Dragon avionics on a Falcon second stage. That thing will arrive in LEO with 15 tons of fuel to spare and plenty of time to dock thanks to GEO capability.Isn't that a little too beefy for this with the Merlin engine?
To ensure ISS structural integrity, the maximum allowable thrust is 6178 N (6.2kN)
My guess for an evaluation would be:1) Modified Cygnus
Quote from: Asteroza on 08/22/2022 10:30 pmQuote from: niwax on 08/22/2022 10:22 pmI guess if you want to go crazy you could also forego the extra vehicle entirely and slap a docking port and some Dragon avionics on a Falcon second stage. That thing will arrive in LEO with 15 tons of fuel to spare and plenty of time to dock thanks to GEO capability.Isn't that a little too beefy for this with the Merlin engine?Try 100 times too strongQuote from: From the RFI supplemental: ISS Deorbit USOS Concept of Operations OverviewTo ensure ISS structural integrity, the maximum allowable thrust is 6178 N (6.2kN)F9 stage has to survive upto year attached to ISS while meeting all stations safety requirements.
Quote from: niwax on 08/22/2022 10:22 pmI guess if you want to go crazy you could also forego the extra vehicle entirely and slap a docking port and some Dragon avionics on a Falcon second stage. That thing will arrive in LEO with 15 tons of fuel to spare and plenty of time to dock thanks to GEO capability.F9 stage has to survive upto year attached to ISS while meeting all stations safety requirements.
I think an proposed h3 launching a improved second stage is so uitable for deorbiting iss
NASA revises contract strategy for ISS deorbit vehicleJeff FoustDecember 7, 2023WASHINGTON — NASA will give companies greater choice in the type of contract to use for producing a deorbit vehicle for the International Space Station.In a procurement notice posted Dec. 5, NASA announced it would allow companies the choice of using either firm fixed price or cost plus incentive fee contract structures for both the design and the production of the U.S. Deorbit Vehicle (USDV).