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EVA Spacesuit B (blue stripes) was returned to Earth inside Shenzhou-20 spacecraft

https://m.weibo.cn/detail/5256763192380685

Image captured from the video
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The satellites are from Galaxy Space
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Advanced Concepts / Re: Feasibility of fusion based launch
« Last post by edzieba on Today at 09:46 am »
It doesn't matter whether it's antimatter, fusion, fission, or whatever, the very basic physics preclude launching with high Isp propulsion systems.

The two equations of interest:

Energy Rate = 1/2mdot*v2
Force = mdot * v

where mdot is the mass flow rate and v is the exhaust velocity.

Assuming we have a 1000t fuel+mass vehicle and it needs a TWR of 1.5 and a deltaV of 9km/sec, and just for fun set the exhaust velocity so that the mass ratio is 2.7:1.

Let's see what variables in the above equations are fixed, and we'll solve for the rest

Your force needs to be 15MN.   the exhaust velocity is 9.2km/sec.

That gives us an mdot of 1630kg/sec and an energy rate of 69GW.

Now there is no propulsion system I can find (chemical, nuclear, ion) that has a kinetic energy efficiency of better than about  0.6, so you divided by that to get the total energy rate and that's 115GW

Now you are in Starship Booster territory which by the same equations above has an mdot of 23,000kg/sec and a total energy rate of 200GW

leaving aside what kind of damage exhaust traveling at 3 times the exhaust velocity of Starship will do your launch pad, that leaves us with about 10km/sec as about the highest exhaust velocity a launchpad could handle, given that Starship's launch pad can barely handle its 200GW of output at 1/3 the exhaust velocity.  And you are still expending 2.7 mass ratio to get to LEO.

Now let's take our exhaust velocity up to 100km/sec, which is more what you want to speed around the solar system in reasonable amounts of time, no staging required, no refuels for a typical journey to Mars or the outer planets, etc

now your mdot is 150kg/sec, but your energy rate is a whopping 750GW/.6 = 1.25TW

I doubt you can supply enough water at high enough pressure to counter 1.25TW of plasma screaming at the concrete launch pad at 100km/sec.



While I agree it's very impractical, there IS a way around this ... Don't use a solid launch pad. Like the Sea Dragon concept (or Heinlein's torchships launching from the Pacific).

There's another potential way around this -- have your propulsion system be able to adjust its exhaust velocity -- ie for takeoff and near the surface, maybe you use extra reaction mass to lower your exhaust velocity and power levels to something a pad can handle, but once you're above a certain altitude, you shift to something more optimized Isp-wise. By that point you also won't need as much thrust, which will help. Still no getting around that ve^2 term, definitely puts an upper limit on the Isp you can realistically use for ground launch.

~Jon
Strap-on water tanks with ground-started fusion drive, in place of strap-on solids (or other high-thrust boosters) and air-start fusion.
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Advanced Concepts / Re: Space elevator
« Last post by StraumliBlight on Today at 09:45 am »
One of the Sci-Fi space elevator books (Fountains of Paradise?) briefly discussed a Mars elevator. The big problem was that that the orbits of Phobos and Deimos are lower than the Aerosynchronous orbit. The Sci-Fi solution was to induce an oscillation of the elevator so it swings out of the way of the moons. This seems infeasible to me. I think you need to de-orbit the moons.

You're thinking of Kim Stanley Robinson's Mars Trilogy, Clarke's The Fountains of Paradise was set on Earth.
5
Chinese Launchers / Re: Tiangong - Chinese Space Station
« Last post by starbase on Today at 09:43 am »
Completed CSS operation milestones:

2021
Apr. 29 at 3:23 UTC - launch of Tianhe on CZ-5B
May 29 at 12:55 UTC - launch of Tianzhou 2 on CZ-7
May 29 at 21:01 UTC - docking of Tianzhou 2 with aft port of Tianhe (+propellant transfer)
June 17 at 1:22 UTC - launch of Shenzhou 12 [Nie Haisheng, Liu Boming and Tang Hongbo] on CZ-2F/G
June 17 at 7:54 UTC - docking of Shenzhou 12 [Nie, Liu, Tang] with forward port of Tianhe
July 4 at 0:11–6:57 UTC - spacewalk (EVA-1) from Tianhe airlock (test of new space suits, installation of foot restraints, work platform and exterior panoramic camera, emergency return to airlock training) [Liu, Tang]
Aug. 20 at 0:38–6:33 UTC spacewalk (EVA-2) from Tianhe airlock (installation of external pump assembly, panoramic camera activation, foot restraints & extravehicular working platform installation on the robotic arm) [Nie, Liu]
Sep. 16 at 0:56 UTC - undocking of Shenzhou 12 from forward port of Tianhe (+rendezvous test at nadir port) [Nie, Liu, Tang]
Sep. 17 at 4:45–4:48–5:34 UTC - jettison of OM & deorbit burn & landing of Shenzhou 12 [Nie, Liu, Tang]
Sep. 18 at 2:25~6:25 UTC - undocking of Tianzhou 2 from aft port of Tianhe and docking with forward port of Tianhe (+propellant transfer testing)
Sep. 20 at 7:10 UTC - launch of Tianzhou 3 on CZ-7
Sep. 20 at 14:08 UTC - docking of Tianzhou 3 with aft port of Tianhe
Oct. 15 at 16:23 UTC - launch of Shenzhou 13 on CZ-2F/G [Zhai Zhigang, Wang Yaping, Ye Guangfu]
Oct. 15 at 22:56 UTC - docking of Shenzhou 13 with nadir port of Tianhe [Zhai, Wang, Ye]
Nov. 7 at 10:51–17:16 UTC spacewalk (EVA-3) from Tianhe airlock (testing of new spacesuit, installation of robotic arm adapter/end effector) [Zhai, Wang]
Dec. 26  at 10:44–16:55 UTC spacewalk (EVA-4) from Tianhe airlock (deployment of external camera platform C, object translation movement testing) [Zhai, Ye]

2022
Jan. 5 at 22:12–22:59 UTC - robotic arm relocation testing of Tianzhou 2 (near port side port)
Jan. 7 at 21:56–23:55 UTC - undocking & docking of Tianzhou 2 at forward port of Tianhe (manual docking test)
Mar. 27 at 7:59 UTC - undocking of Tianzhou 2 from forward port of Tianhe for EOM
Mar. 31 at 10:40 UTC - reentry of Tianzhou 2 over the South Pacific
Apr. 14 at 16:44 UTC - undocking of Shenzhou 13 from nadir port of Tianhe [Zhai, Wang, Ye]
Apr. 16 at 1:07–1:09~1:31–1:56 UTC - jettison of OM & deorbit burn & jettison of PM & landing of Shenzhou 13 [Zhai, Wang, Ye]
Apr. 19 at 21:02–01:06 UTC - undocking of Tianzhou 3 from aft port & docking at forward port of Tianhe
May 10 at 17:56 UTC - launch of Tianzhou 4 on CZ-7
May 11 at 0:47 UTC - docking of Tianzhou 4 with aft port of Tianhe
June 5 at 2:44 UTC - launch of Shenzhou 14 on CZ-2F/G [Chen Dong, Liu Yang, Cai Xuzhe]
June 5 at 9:42 UTC - docking of Shenzhou 14 with nadir port of Tianhe [Chen, Liu, Cai]
July 17 at 2:59 UTC - undocking of Tianzhou 3 from forward port of Tianhe for EOM
July 24 at 6:22 UTC - launch of Wentian on CZ-5B
July 24 at 19:08–19:13 UTC - (soft/hard) docking of Wentian at forward port of Tianhe
July 27 at 3:31 UTC - reentry of Tianzhou 3 over the South Pacific
Sep. 2 at 10:26–16:33 UTC - spacewalk (EVA-5) from Wentian airlock (installation of coolant pump on Wentian, raising a panoramic camera and testing of the small robotic arm) [Chen, Liu]
Sep. 17 at 5:35–9:47 UTC - spacewalk (EVA-6) from Wentian airlock (installation of foot restraint B and an assisting hatch handle, installation of a circulating pump and demonstration of extravehicular emergency rescue procedures) [Chen, Cai]
Sep. 30 3:45–4:44 UTC - robotic relocation of Wentian from forward to starboard on Tianhe
Oct. 31 at 7:37 UTC - launch of Mengtian on CZ-5B
October 31 at 20:27 UTC - docking of Mengtian at forward port of Tianhe
Nov. 3 at 0:48–1:32 UTC - robotic relocation of Mengtian from forward to port on Tianhe
Nov. 9 at 6:55 UTC - undocking of Tianzhou 4 from aft port of Tianhe for EOM
Nov. 12 at 2:03 UTC - launch of Tianzhou 5 on CZ-7
Nov. 12 at 4:10 UTC - docking of Tianzhou 5 with aft port of Tianhe
Nov. 13 at 22:02 UTC - deployment of CubeSat Zhixing 3A (智星三号A, SmartSAT 3A) from Tianzhou 4
Nov. 14 at 23:21 UTC - reentry of Tianzhou 4
Nov. 17 at 3:16–8:50 UTC - spacewalk (EVA-7) from Wentian airlock (installing an inter-module connecting device (handrail) and raising the Wentian panoramic camera A) [Chen, Cai]
Nov. 29 at 15:08 UTC - launch of Shenzhou 15 on CZ-2F/G [Fei, Deng, Zhang]
Nov. 29 at 21:41 UTC - docking of Shenzhou 15 with forward port of Tianhe [Fei, Deng, Zhang]
Dec. 4 at 3:01 UTC - undocking of Shenzhou 14 from nadir port of Tianhe
Dec. 4 at ~11:20–11:22~11:45–12:08 UTC - jettison of OM & deorbit burn & jettison of PM & landing of Shenzhou 14 [Chen, Liu, Cai]
Dec. 18 at 1:30 UTC - deployment of CubeSat XW 4 (CAS 10, Macau Student Science 1) from Tianzhou 5 external dispenser

2023
Feb. 9 at 9:10–16:16 UTC - spacewalk (EVA-8) from Wentian airlock (installation of an external pump on Mengtian) [Fei, Zhang]
Feb. 28 - spacewalk (EVA-9) from Wentian airlock [Fei, Zhang]
Mar. 30 - spacewalk (EVA-10) from Wentian airlock [Fei, Zhang]
Apr. 15 - spacewalk (EVA-11) from Wentian airlock (installation of an external pump, laying inter-module cables and installation of a supporting bar for the exposed payloads platform) [Fei, Zhang]
May 5 at 7:26 UTC - undocking of Tianzhou 5 from aft port of Tianhe
May 10 at 13:22 UTC - launch of Tianzhou 6 on CZ-7
May 10 at 21:16 UTC - docking of Tianzhou 6 to aft port of Tianhe
May 30 at 1:31 UTC - launch of Shenzhou 16 on CZ-2F/G [Jing, Zhu, Gui]
May 30 at 8:29 UTC - docking of Shenzhou 16 to nadir port of Tianhe [Jing, Zhu, Gui]
June 3 at 13:29 UTC - undocking of Shenzhou 15 from forward port of Tianhe [Fei, Deng, Zhang]
June 3 at 21:41–21:43–22:04–22:07–22:18–22:33 UTC - jettison of OM & deorbit burn & jettison of PM & reentry & parachute deployment & landing of Shenzhou 15 [Fei, Deng, Zhang]
June 5 at 19:10 UTC - docking of Tianzhou 5 with forward port of Tianhe
July 20 at ~5:40–13:40 UTC - spacewalk (EVA-12) from Wentian airlock (deployment of external panoramic cameras B on Tianhe and A&B on Mengtian) [Jing, Zhu]
Sep. 11 at 8:46 UTC - undocking of Tianzhou 5 from forward port of Tianhe for EOM & reentry
Sep. 12 at 1:13 UTC - reentry of Tianzhou 5
Oct. 26 at 3:14 UTC - launch of Shenzhou 17 on CZ-2F/G [Tang Hongbo, Tang Shengjie, Jiang Xinlin]
Oct. 26 at 9:46 UTC - docking of Shenzhou 17 to forward port of Tianhe [Tang, Tang, Jiang]
Oct. 30 at 12:37 UTC - undocking of Shenzhou 16 from nadir port of Tianhe [Jing, Zhu, Gui]
Oct. 30 at 23:21–23:22–23:48~23:51–23:57–0:11 UTC - jettison of OM & deorbit burn & jettison of PM & reentry & parachute deployment & landing of Shenzhou 16 [Jing, Zhu, Gui]
Dec. 21 at 6:10–13:35 UTC - spacewalk (EVA-13) from Wentian airlock (repair of a Tianhe module solar array damaged by micrometeor strikes) [Tang, Tang]

2024
Jan. 12 at 8:02 UTC - undocking of Tianzhou 6 from aft port of Tianhe for EOM & reentry
Jan. 17 at 14:27 UTC - launch of Tianzhou 7 on CZ-7
Jan. 17 at 17:46 - docking of Tianzhou 7 to aft port of Tianhe
Jan. 18 at 6:43 UTC - deployment of CubeSat Dalian 1 (Lianli) from Tianzhou 6 external dispenser
Jan. 19 at 12:37 UTC - reentry of Tianzhou 6
Mar. 1 at ~21:30–5:33 UTC - spacewalk (EVA-14) from Wentian airlock (repair of a Tianhe module solar array damaged by micrometeor strikes) [Tang, Jiang]
Apr. 25 at 12:59 - launch of Shenzhou 18 on CZ-2F/G [Ye Guangfu, Li Guangsu, Li Cong]
Apr. 25 at 19:32 - docking of Shenzhou 18 to nadir port of Tianhe [Ye, Li, Li]
Apr. 30 at 0:43 UTC - undocking of Shenzhou 17 from forward port of Tianhe [Tang, Tang, Jiang]
Apr. 30 at 8:55–8:56–9:13–9:33–9:46 UTC - jettison of OM & deorbit burn & reentry & parachute deployment & landing of Shenzhou 17 [Tang, Tang, Jiang]
May 28 at 0:35–8:58 UTC - spacewalk (EVA-15) from Wentian airlock (installation of space debris protection, inspection of extravehicular equipment & facilities) [Ye, Li Guangsu]
July 3 at ~8:21–14:51 UTC - spacewalk (EVA-16) from Wentian airlock (installation of space debris protection, inspection of extravehicular equipment & facilities) [Ye, Li Cong]
Oct. 29 at 20:27 UTC - launch of Shenzhou 19 on CZ-2F/G [Cai Xuzhe, Song Lingdong, Wang Haoze]
Oct. 30 at 3:00 UTC - docking of Shenzhou 19 to forward port of Tianhe [Cai, Song, Wang]
Nov. 3 at 8:12 UTC - undocking from nadir port of Tianhe & landing of Shenzhou 18 [Ye, Li, Li]
Nov. 3 at at 16:34–16:35–16:58–17:03–17:11–17:24 UTC - jettison of OM & deorbit burn & jettison of PM & reentry & parachute deployment & landing of Shenzhou 18 [Ye, Li, Li]
Nov. 10 at 8:30 UTC - undocking of Tianzhou 7 from aft port of Tianhe for EOM & reentry
Nov. 15 at 15:30 UTC - launch of Tianzhou 8 on CZ-7
Nov. 15 at 18:32 UTC - docking of Tianzhou 8 to aft port of Tianhe
Nov. 16 - deployment of CubeSat Nanjing (Bayi 08) from Tianzhou 7 external dispenser
Nov. 17 at 13:25 UTC - reentry of Tianzhou 7
Dec. 17 at 4:51–13:57 UTC - spacewalk (EVA-17) from Wentian airlock (installation of debris protection equipment, inspecting external facilities, checking various apparatuses) [Cai, Song]

2025
Jan. 20 at 8:55–17:12 UTC - spacewalk (EVA-18) from Wentian airlock (installation of debris protection equipment, inspecting external facilities, checking various apparatuses) [Cai, Song]
Mar. 21 at 5:45–12:50 UTC - spacewalk (EVA-19) from Wentian airlock (installation of debris protection equipment & moving aids, inspecting external facilities) [Cai, Song]
Apr. 24 at 9:17 UTC - launch of Shenzhou 20 on CZ-2F/G [Chen Dong, Chen Zhongrui, Wang Jie]
Apr. 24 at 15:49 UTC - docking of Shenzhou 20 to nadir port of Tianhe [Chen, Chen, Wang]
Apr. 29 at 20:00 - undocking of Shenzhou 19 from forward port of Tianhe [Cai, Song, Wang]
Apr. 29 at 4:17–4:18–4:42–4:45–4:54–5:08 UTC - jettison of OM & deorbit burn & jettison of PM & reentry & parachute deployment & landing of Shenzhou 19 [Cai, Song, Wang]
May 22 0:50–8:49 UTC - spacewalk (EVA-20) from Tianhe airlock (installation of debris protection equipment & inspection and disposal of extravehicular equipment and facilities) [Chen, Chen]
June 26 7:04–13:29 UTC - spacewalk (EVA-21) from Wentian airlock (installation of debris protection equipment, inspections & maintenance and installation of foot restraints & adapter interfaces on the external platform) [Chen, Chen]
July 8 at 7:09 UTC - undocking of Tianzhou 8 from aft port of Tianhe for EOM & reentry
July 8 at 22:46 UTC - reentry of Tianzhou 8
July 14 at 21:34 UTC - launch of Tianzhou 9 on CZ-7
July 15 at 0:52 UTC - docking of Tianzhou 9 to aft port of Tianhe
Aug. 15 at ~8:17–14:47 UTC - spacewalk (EVA-22) from Wentian airlock (installation of debris protection equipment, inspections & maintenance) [Chen Dong, Wang]
Sep. 25 at ~11:35–17:35 UTC - spacewalk (EVA-23) from Wentian airlock (installation of debris protection equipment, inspections & maintenance) [Chen Zhongrui, Wang]
Oct. 31 at 15:44 UTC - launch of Shenzhou 21 on CZ-2F/G [Zhang Lu (张陆), Wu Fei (武飞) and Zhang Hongzhang (张洪章)]
Oct. 31 at 19:22 UTC - docking of Shenzhou 21 to forward port of Tianhe [Zhang, Wu, Zhang]
Nov. 14 at 3:14 UTC - undocking of Shenzhou 21 from forward port of Tianhe [Chen, Chen, Wang]
Nov. 14 at 7:50–7:51–8:15–8:18–8:27–8:40 UTC - jettison of OM & deorbit burn & jettison of PM & reentry & parachute deployment & landing of Shenzhou 21 [Chen, Chen, Wang]
Nov. 25 at 4:11 UTC - launch of Shenzhou 22 on CZ-2F/G [uncrewed]
Nov. 25 at 7:50 UTC - docking of Shenzhou 22 to forward port of Tianhe [uncrewed]
December 9 at 2:28–8:45 UTC - spacewalk (EVA-24) from Wentian airlock (inspecting and photographing the windows of Shenzhou 20, installation of space debris protection) [Zhang Lu, Wu]

2026
Jan. 18 at 16:23 UTC - undocking of Shenzhou 20 from nadir port of Tianhe [uncrewed]
Jan. 19 at 1:34 UTC - landing of Shenzhou 20 [uncrewed]


Guesstimated current timeline of upcoming CSS operations:

(TBC) Apr. 14 - undocking of Tianzhou 9 from aft port of Tianhe for EOM & reentry
(TBC) Apr. 14 - launch of Tianzhou 10 on CZ-7
(TBC) Apr. 14 - docking of Tianzhou 10 to aft port of Tianhe
(TBC) Apr. 14 - reentry of Tianzhou 9
(TBC) May 30 - launch of Shenzhou 23 on CZ-2F/G
(TBC) May 30 - docking of Shenzhou 23 to nadir port of Tianhe
NET October - launch of Qingzhou 2 on Kinetica 2
NET October - docking of Qingzhou 2 to aft? port of Tianhe
(TBC) Nov. 23 - launch of Shenzhou 24 on CZ-2F/G [Pakistani astronaut]
(TBC) Nov. 23 - docking of Shenzhou 24 to forward port of Tianhe
NET December - launch of Mengzhou 1 on CZ-10A
NET December - docking of Mengzhou 1 to nadir port of Tianhe

2027
NET 2027 - launch of Xuntian on CZ-5B
Late 2027? - launch of multipurpose module on CZ-5B

2033
Early 2033? - launch of science module on CZ-5B
Late 2033? - launch of science module on CZ-5B

Corrections & input welcome!

Edit Jan. 19
6
Spaceflight Entertainment and Hobbies / Re: Space Stamps
« Last post by salyut on Today at 09:40 am »
September 27, 1969, Maldives.
7
Blue Origin / Re: Blue Origin's BE-4 Engine
« Last post by Rakietwawka2021 on Today at 09:29 am »
I think subcooling and increased thrust are coming in the same upgrade
8
Any pictures of the damaged window, be it now after landing (it seems to be hidden either by a circular cover or the square tarp) or in EVA pictures before/after the stabilization procedures the astronauts carried out?
9
Missions To Mars (HSF) / Re: Mars vs Antarctica
« Last post by Proponent on Today at 09:06 am »
Recent events offer further evidence that Antarctica is not a gold mine of wealth waiting to be developed, if only that annoying Antarctic Treaty System could be abolished (which it can be). The US president now talks openly of acquiring territory by force for, among other things, the exploitation of natural resources, allies' concerns, locals' wishes, treaties and international law be damned. Yet even he has yet to mention Antarctica.
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