Launch of the Tianhe core module on a Long March 5B could take place at Wenchang in early 2021. This will be followed by a crewed Shenzhou flight, from Jiuquan, and a Tianzhou cargo mission. The first of two experiment modules will then launch for docking with Tianhe. In total 11 launches will be conducted to complete the construction of the space station by around 2023
Does this mean that the launch of the first module has been pushed back to 2021?
https://vk.com/chinaspaceflight?w=wall-119361981_6416
Quote from: zandr on 04/03/2020 10:06 pmhttps://vk.com/chinaspaceflight?w=wall-119361981_6416I've just realized: the docking port is androgynous. At least it has the hooks to act as active or passive.
Surely, it would just be a case of redesigning the 'LOX Turbopump fault' and flying again when the problem is resolved - however long that takes? I doubt the Chinese space agency would just shelve something for good when a problem could be fixed.
…One astronaut can operate the mechanical arm inside the capsule while another works outside. The space station will have two kinds of mechanical arms, and the coordination between astronauts and mechanical arms will enable the construction and maintenance of the station.
Some good shots of the station's docking ports here. Can anyone tell whether they look like APAS or IDS standard? (I'm not visually familiar enough with the differences to distinguish them...)In the past China has used a derivative of APAS on their stations, but there have been reports/statements that they intend to make Tiangong (and visiting vehicles going forward) compatible with the newer IDS standard. I'm curious whether they are actually going through with that or if that was just an unfounded/misinterpreted rumor.At the moment the idea of transnational space station visits with China (Dragon/Starliner/DC to Tiangong or Shenzhou to ISS) would seem like a pipe dream on legal grounds, but it would make a lot of sense to at least try to make them as compatible as possible, so as to keep options open. (IDS is supposed to be structurally superior to boot - less impact on the station's structure from repeated dockings, which also makes it easier to abort a docking since approach velocity is reduced.)
Quote from: gemmy0I on 12/26/2020 09:31 pmSome good shots of the station's docking ports here. Can anyone tell whether they look like APAS or IDS standard? (I'm not visually familiar enough with the differences to distinguish them...)In the past China has used a derivative of APAS on their stations, but there have been reports/statements that they intend to make Tiangong (and visiting vehicles going forward) compatible with the newer IDS standard. I'm curious whether they are actually going through with that or if that was just an unfounded/misinterpreted rumor.At the moment the idea of transnational space station visits with China (Dragon/Starliner/DC to Tiangong or Shenzhou to ISS) would seem like a pipe dream on legal grounds, but it would make a lot of sense to at least try to make them as compatible as possible, so as to keep options open. (IDS is supposed to be structurally superior to boot - less impact on the station's structure from repeated dockings, which also makes it easier to abort a docking since approach velocity is reduced.)APAS is the version of IDSS offered by RSC Energia. A newer version of APAS is in development for proposed projects (i.e. Gateway et al) that is fully IDSS compliant with built in redundancy features. The Chinese licenced version of APAS is known in English as CDS or China Docking System. China required it to be built to ISS MCB docking system requirements so that each station can serve the other as well as commercial stations in emergency situations.
Quote from: russianhalo117 on 12/26/2020 10:15 pmQuote from: gemmy0I on 12/26/2020 09:31 pmSome good shots of the station's docking ports here. Can anyone tell whether they look like APAS or IDS standard? (I'm not visually familiar enough with the differences to distinguish them...)In the past China has used a derivative of APAS on their stations, but there have been reports/statements that they intend to make Tiangong (and visiting vehicles going forward) compatible with the newer IDS standard. I'm curious whether they are actually going through with that or if that was just an unfounded/misinterpreted rumor.At the moment the idea of transnational space station visits with China (Dragon/Starliner/DC to Tiangong or Shenzhou to ISS) would seem like a pipe dream on legal grounds, but it would make a lot of sense to at least try to make them as compatible as possible, so as to keep options open. (IDS is supposed to be structurally superior to boot - less impact on the station's structure from repeated dockings, which also makes it easier to abort a docking since approach velocity is reduced.)APAS is the version of IDSS offered by RSC Energia. A newer version of APAS is in development for proposed projects (i.e. Gateway et al) that is fully IDSS compliant with built in redundancy features. The Chinese licenced version of APAS is known in English as CDS or China Docking System. China required it to be built to ISS MCB docking system requirements so that each station can serve the other as well as commercial stations in emergency situations.Thanks - that clears things up quite a bit!I keep forgetting that the IDSS standard, like APAS before it, allows for substantial independence in how it's implemented mechanically by different nations and companies, even as the interface itself is mutually compatible. The last time the U.S. built a docking system indigenously prior to NDS was for Apollo-Soyuz, and apparently their implementation of that original version of APAS was quite different mechanically than the Soviet one. So I can see how NASA/U.S.-focused sources would draw a sharper terminological line between "APAS" (referring to the legacy high-impact system as implemented by the PMAs and Shuttle's docking adapter) versus "IDS/NDS" (the modern low-impact system as implemented by the IDAs and Commercial crew vehicles), compared to Russian/Chinese-focused sources. NDS, NASA's reference implementation of IDSS developed by Boeing out of the LIDS project and used by the IDAs, seems to be a clean-sheet design deriving from neither the historical American Apollo-Soyuz APAS implementation, nor from the Russian-proprietary implementation used on Shuttle-ISS/Mir, hence NASA doesn't refer to their new ports as "APAS". Likewise SpaceX, which opted to do their own clean-sheet implementation of IDSS instead of buying Boeing's, wouldn't be able to claim APAS heritage per se. But since Russia has been continuously producing and evolving docking hardware from the 60's to the present day, it stands to reason their implementation of IDSS would have more substantial mechanical heritage in APAS, hence why they continue to use that term to describe it. (Did I get all that right? )I do find it interesting that China is choosing to put its new space station in a ~42° orbit instead of a ~51.6° orbit matching the ISS's. Having compatible docking ports is nice but not especially useful when the two stations are separated by so much delta-v; it limits the utility in "emergency situations" to ones where one nation's vehicle is launching fresh from the ground to visit the other's station, as opposed to traveling from one station to the other. Just as Mir and the ISS were supposed to overlap and allow for cross-visits (as was done between Mir and Salyut 7), it seems most if not all near-term commercial stations will be joining the 51.6° inclination for that reason. (Axiom Station in particular, being the most credible plan for a commercial station right now, will have to be at 51.6° because it will start out as an extension to the ISS.)It also freezes out Russia from sending Soyuz/Progress/Oryol vehicles to the Chinese station since none of their launch sites can reach 42°, which strikes me as strange considering how closely involved Russia and China have been on this project (and Russia's recently stated intent to double down on that partnership in the future instead of getting more involved with the U.S.). Even if they launched straight east from Baikonur (which I suppose they could do in partnership with China, since Baikonur's azimuth restrictions are driven by the need to avoid overflying Mongolia), they still wouldn't be able to get any lower than ~45° without a substantial dogleg. Are China's launches for station modules and visiting vehicles so mass-constrained that they can't spend the small extra delta-v to go to 51.6°? It just seems like the smarter play considering that's where all the action is.Or am I overestimating the difficulty of the dogleg necessary to get to 42° from Baikonur or Vostochny? I can't imagine Soyuz-2.1a being able to pull it off given it's tightly mass-constrained on Soyuz and Progress launches, but maybe if they bumped it up to a Soyuz-2.1b they could do it?
Quote from: gemmy0I on 12/27/2020 04:31 amQuote from: russianhalo117 on 12/26/2020 10:15 pmQuote from: gemmy0I on 12/26/2020 09:31 pmSome good shots of the station's docking ports here. Can anyone tell whether they look like APAS or IDS standard? (I'm not visually familiar enough with the differences to distinguish them...)In the past China has used a derivative of APAS on their stations, but there have been reports/statements that they intend to make Tiangong (and visiting vehicles going forward) compatible with the newer IDS standard. I'm curious whether they are actually going through with that or if that was just an unfounded/misinterpreted rumor.At the moment the idea of transnational space station visits with China (Dragon/Starliner/DC to Tiangong or Shenzhou to ISS) would seem like a pipe dream on legal grounds, but it would make a lot of sense to at least try to make them as compatible as possible, so as to keep options open. (IDS is supposed to be structurally superior to boot - less impact on the station's structure from repeated dockings, which also makes it easier to abort a docking since approach velocity is reduced.)APAS is the version of IDSS offered by RSC Energia. A newer version of APAS is in development for proposed projects (i.e. Gateway et al) that is fully IDSS compliant with built in redundancy features. The Chinese licenced version of APAS is known in English as CDS or China Docking System. China required it to be built to ISS MCB docking system requirements so that each station can serve the other as well as commercial stations in emergency situations.Thanks - that clears things up quite a bit!I keep forgetting that the IDSS standard, like APAS before it, allows for substantial independence in how it's implemented mechanically by different nations and companies, even as the interface itself is mutually compatible. The last time the U.S. built a docking system indigenously prior to NDS was for Apollo-Soyuz, and apparently their implementation of that original version of APAS was quite different mechanically than the Soviet one. So I can see how NASA/U.S.-focused sources would draw a sharper terminological line between "APAS" (referring to the legacy high-impact system as implemented by the PMAs and Shuttle's docking adapter) versus "IDS/NDS" (the modern low-impact system as implemented by the IDAs and Commercial crew vehicles), compared to Russian/Chinese-focused sources. NDS, NASA's reference implementation of IDSS developed by Boeing out of the LIDS project and used by the IDAs, seems to be a clean-sheet design deriving from neither the historical American Apollo-Soyuz APAS implementation, nor from the Russian-proprietary implementation used on Shuttle-ISS/Mir, hence NASA doesn't refer to their new ports as "APAS". Likewise SpaceX, which opted to do their own clean-sheet implementation of IDSS instead of buying Boeing's, wouldn't be able to claim APAS heritage per se. But since Russia has been continuously producing and evolving docking hardware from the 60's to the present day, it stands to reason their implementation of IDSS would have more substantial mechanical heritage in APAS, hence why they continue to use that term to describe it. (Did I get all that right? )I do find it interesting that China is choosing to put its new space station in a ~42° orbit instead of a ~51.6° orbit matching the ISS's. Having compatible docking ports is nice but not especially useful when the two stations are separated by so much delta-v; it limits the utility in "emergency situations" to ones where one nation's vehicle is launching fresh from the ground to visit the other's station, as opposed to traveling from one station to the other. Just as Mir and the ISS were supposed to overlap and allow for cross-visits (as was done between Mir and Salyut 7), it seems most if not all near-term commercial stations will be joining the 51.6° inclination for that reason. (Axiom Station in particular, being the most credible plan for a commercial station right now, will have to be at 51.6° because it will start out as an extension to the ISS.)It also freezes out Russia from sending Soyuz/Progress/Oryol vehicles to the Chinese station since none of their launch sites can reach 42°, which strikes me as strange considering how closely involved Russia and China have been on this project (and Russia's recently stated intent to double down on that partnership in the future instead of getting more involved with the U.S.). Even if they launched straight east from Baikonur (which I suppose they could do in partnership with China, since Baikonur's azimuth restrictions are driven by the need to avoid overflying Mongolia), they still wouldn't be able to get any lower than ~45° without a substantial dogleg. Are China's launches for station modules and visiting vehicles so mass-constrained that they can't spend the small extra delta-v to go to 51.6°? It just seems like the smarter play considering that's where all the action is.Or am I overestimating the difficulty of the dogleg necessary to get to 42° from Baikonur or Vostochny? I can't imagine Soyuz-2.1a being able to pull it off given it's tightly mass-constrained on Soyuz and Progress launches, but maybe if they bumped it up to a Soyuz-2.1b they could do it?The IDA's development, design and manufacture involved Boeing, RSC Energia et al. The IDSS calls for an impact range supporting legacy APAS impact velocities to LIDS ultra low impact velocities. This may change in a future revision years to decades in the future.Chinese launches can reach 51.6. They have been back and forth on the planned inclination. Also Russia has been given frozen water over the past few years in Chinese discussions because China's Central Committee et al have declined to give authorization and the Chinese side has to have approvals for anything beyond pondering discussion. If you have a subscription Russian Space Web this is greatly detailed and goes in to the repeated deal breakers including topics outside of space. It heavily relies on Russia increasingly not having much to offer major technologies wise with China having lapped Russia in many fields. It also comes down to that if it is not approved in China's 5 year plans and not proposed first by them then approvals are hard to come by.
China is choosing to put its new space station in a ~42° orbit
Here is a thread about CSST (Chinese Space Station Telescope): A low-orbit, 2-m NUV-optical space telescope focusing on large sky surveys. It is a separate module of the new space station and planned to launch around 2025.The telescope has an off-axis TMA design using SiC mirrors with some "active" capability for in-orbit adjustment. It has ~1.1 deg^2 FoV for the main sky survey while having four separate small instruments. The designed resolution is around 0.12-0.15 arcsec.The main goal of CSST is a multi-band (NUV, u, g, r, i, z), large area (17500 deg^2) sky survey to r>25 mag that also has grism spectra coverage (r~22). There is also a 400 deg^2 deep field and 1 or 2 much smaller UD fields.The main instrument is a very complicated camera for the main survey. Instead of a sophisticated filter change mechanism, the focal plane may remind you of the original SDSS survey: each detector has a fixed filter on it.Another important component is a multi-channel imager (MCI) that can observe in three-band simultaneously. It has a 7.7x7.7 arcmin FoV with 0.05 arcsec/pixel resolution. It will bring ~30 broad+medium+narrow band filters. I call it "poor man's WFC3".CSST will also carry a small optical IFU instrument using an image slicer, mainly for scientific demonstration. It has a 6x6 arcsec FoV, 0.2 arcsec spatial resolution, and covers 0.4-0.9 micron in wavelength with R>1000.Another interesting aspect of CSST is: it can dock to the space station for maintenance and upgrade in the future! In the current design, >20 modules of the telescope can be replaced or have the potential for upgrade.[...]Some personal notes: I have been involved in CSST science preparation for a little bit, and it will be an important part of my plan for the next five years. While being super excited about it, I also feel very nervous... Chinese astronomy community is still pretty new and relatively small. Compared to the American and European communities, we still lack the experience to handle such a complex space telescope project. So there will a lot of trial and error... Luckily, we do have a group of brilliant young scientists working on it, and that gives me all the hope I need. Hopefully, I can put this ambitious project on your radar. And hopefully, we can develop many international collaborations using CSST data.
