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JAXA (& other Japanese) Launch and Discussion Thread


tater

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7 hours ago, tater said:

Captured by the little rover.

Spoiler

Where is the Mun or Bust CSM? - KSP1 Discussion - Kerbal Space Program  Forums

Jeb would be proud :cool:

 

Something that's been bugging me is why can't they just use the thrusters to push it over? It doesn't look like it's embedded too deep.

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1 hour ago, Minmus Taster said:
  Reveal hidden contents

Where is the Mun or Bust CSM? - KSP1 Discussion - Kerbal Space Program  Forums

Jeb would be proud :cool:

 

Something that's been bugging me is why can't they just use the thrusters to push it over? It doesn't look like it's embedded too deep.

It works in kerbal all the time, might as well give it a shot.

More info...

 

 

Edited by darthgently
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2 hours ago, Minmus Taster said:
  Reveal hidden contents

Where is the Mun or Bust CSM? - KSP1 Discussion - Kerbal Space Program  Forums

Jeb would be proud :cool:

 

Something that's been bugging me is why can't they just use the thrusters to push it over? It doesn't look like it's embedded too deep.

The telemetry from the stream made it seem like all the thrusters were in a ring on the bottom facing down so it would be hard to tip it with those 

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Looks like one of the main engines broke apart at around 50 meters, one of the nozzles was caught in a navigation image falling away. It's really a miracle it landed at all, and it made it well within the 100 meter target area, JAXA should be proud of their work here.

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M4dcMr0.png

Oh google translate, what would we do without you :rolleyes:

 

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  • 2 weeks later...

 Friday’s H3 test launch was a success. This H3 version used two core engines and two solid side boosters. But JAXA also plans a version with three core engines and no side boosters.

116155-AE-273-D-4672-A932-50321-B31081-E

 

 This all-liquid version will have a payload of 4 tons to SSO, sun-synchronous orbit. Payload to LEO is generally 50% to 60% higher, so the 3 engine no SRB H3 will have approx. 6 tons to LEO capability. This would have the capability of launching a Gemini class capsule to LEO, which had a 3.8 ton mass. 

 An all-liquid H3 for a manned launcher would not have the safety issues of using solid rockets. Europe and India are racing to have the next manned orbital launcher. Japan should join the race.

 

  Bob Clark

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On 2/16/2024 at 10:10 PM, Exoscientist said:

 An all-liquid H3 for a manned launcher would not have the safety issues of using solid rockets. Europe and India are racing to have the next manned orbital launcher. Japan should join the race.

As a Japanese person I strongly disagree. The country is currently faced with a severe population crisis that will yield ugly results in a couple decades if nothing is done about it. Now is not the time to be spending money on something better done by buying seats from SpaceX.

Furthermore, a Gemini style capsule would be utterly useless.

Also, I don't understand your second sentence. India's Gaganyaan is not intended to be a commercial vehicle and SUSIE or whatever Europe is proposing won't be around until a decade or so... at which point the real "next manned orbital launcher" will be on the scene- Starship. And if you meant "the next manned orbital launcher" for those specific countries, they aren't the "next" launcher because there was no previous European or Indian crewed launcher.

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8 hours ago, SunlitZelkova said:

severe population crisis

I know this is a side issue - and one affecting other advanced economies like SK, etc., but I wonder if it will be as problematic as predicted.  Certainly the world has never experienced a net reduction in population (as some predict peak human population @ 2080). But I wonder if this fear is based on the 'traditional way of doing things'.

Given that necessity is the mother of invention, a country like Japan is highly likely to figure out a solution.  One that may rely on good relationships with other countries - something Japan enjoys. 

Having said that - I agree that so long as purchasing seats is viable for human launch, that makes economic sense - I still would hate to see a nation with the technical and manufacturing skill of Japan get out of space entirely.  

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 By “next” manned launcher,  I mean the next space agency in the world to achieve manned spaceflight after the Russians, Americans, and Chinese.

 By the way, I looked up the Apollo Command capsule and found that the capsule itself without the service module only weighed 5,800 kg. The Apollo service module provided the propulsion for entering and exiting from lunar orbit and wouldn’t be needed for missions just to LEO:

COMMAND MODULE 
Crew size: 3 
Length: 3.5 m 
Maximum diameter: 3.9 m 
Habitable volume: 6.17 m3 
Total mass: about 5,806 kg 
(structure 1,567 kg; heat shield 848 kg; reaction control system 400 kg; recovery equipment 245 kg; navigation equipment 505 kg; telemetry equipment 200 kg; electrical equipment 700 kg; communications systems 100 kg; crew seats & provisions 550 kg; crew mass 216 kg; misc contingency 200 kg; environmental control system 200 kg; propellant 75 kg) 
Reaction control system 
    thrusters: 12 x 410 N 
    propellant: NTO/MMH 
    specific impulse: 290 s 
    total impulse: 257 kNs 
L/D hypersonic: 0.3 
Power: Ag-Zn batteries; 3 × 40 Ah each, 28 V DC; 3.4 kWh; inverters produced 115 V AC 
Environment: pure oxygen at 340 mbar 
http://www.braeunig.us/space/specs/apollo.htm

 Also, surprising is how little mass is required for the environmental control system, at only 200 kg out of the 5,800 kg.

   Bob Clark

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1 hour ago, Exoscientist said:

 By “next” manned launcher,  I mean the next space agency in the world to achieve manned spaceflight after the Russians, Americans, and Chinese.

 By the way, I looked up the Apollo Command capsule and found that the capsule itself without the service module only weighed 5,800 kg. The Apollo service module provided the propulsion for entering and exiting from lunar orbit and wouldn’t be needed for missions just to LEO:

COMMAND MODULE 
Crew size: 3 
Length: 3.5 m 
Maximum diameter: 3.9 m 
Habitable volume: 6.17 m3 
Total mass: about 5,806 kg 
(structure 1,567 kg; heat shield 848 kg; reaction control system 400 kg; recovery equipment 245 kg; navigation equipment 505 kg; telemetry equipment 200 kg; electrical equipment 700 kg; communications systems 100 kg; crew seats & provisions 550 kg; crew mass 216 kg; misc contingency 200 kg; environmental control system 200 kg; propellant 75 kg) 
Reaction control system 
    thrusters: 12 x 410 N 
    propellant: NTO/MMH 
    specific impulse: 290 s 
    total impulse: 257 kNs 
L/D hypersonic: 0.3 
Power: Ag-Zn batteries; 3 × 40 Ah each, 28 V DC; 3.4 kWh; inverters produced 115 V AC 
Environment: pure oxygen at 340 mbar 
http://www.braeunig.us/space/specs/apollo.htm

 Also, surprising is how little mass is required for the environmental control system, at only 200 kg out of the 5,800 kg.

   Bob Clark

The Apollo capsule was also at 100 percent oxygen, 1/3 atmospheric pressure. As most capsules today are focused on transfers to and from long term LEO habitats, you're going to end up with a heavier structure and environmental control system for something that is sea level pressure nitrogen and oxygen.

You also state that the service module would not be needed for LEO missions. While if they had done this a lot, they doubtless would have made a smaller service module, they would have certainly needed a service module to do anything more than a suborbital hop. That thing provides power generation, I think oxygen and water, propulsion, rcs to dock with, and a lot more.

If you just wanted the clout of having sent people to space, sure, but such a spacecraft would be utterly incapable of doing anything more than that.

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