The road to the moon and beyond to Mars.

[Fen End Pit]

2 hours ago, Flying Pig said:

Scott Manley's analysis:

 

 

I loved the phrase 'engine rich exhaust'

David

[Flying Pig]

A short from Scott Manley discussing the termination of the mission. The comments on this one are interesting too.

 

 

[Ozexpatriate]

This is a 'bummer' - the iSpace, Hakuto-R Mission 1 (with Dubai's Mohammed bin Rashid Space Centre rover) is MIA.

 

CNN: Commercial lunar lander presumed lost after historic moon landing attempt

 

This follows failed Israeli and Indian lunar landers in 2019. Space travel is hard to get right.

 

Edited April 25, 2023 by Ozexpatriate

[ERIC ALLTORQUE]

The issue with this now is how do they make the launch table usable as the boosters and ships will start to stack up. the next booster will have the electric enging gimbal and i guess the hydraulic system was a probable cause of loss of flight control on this launch with the HPU,s being damaged again by concrete flying,the huge flare of yellow and black smoke of it being not long after launch. This will take a rethink and time to sort the solution

[Flying Pig]

This video (one of many similar of varying quality) is interesting as it gives a different perspective from the professional ones taken from much closer to the launch site.  Link offset to the launch itself.

 

 

[woodenhead]

Lovely to see SpaceX adding to the greenhouse gases with each test of a rocket solution that looks out of the 1950s.

 

Ok, so it is clever to use a lot of engines and some of the elements can land themselves, not all do as payload determines whether a reusable rocket or a single use rocket is used.  But, these monsters burn methane, the Space Shuttle used oxygen and hydrogen, why does SpaceX have to rely on something we want less off?

 

Then there is the whole idea of rockets themselves, SpaceX even touted the idea of using them as transport craft on intercontinental trips - yes in place of C5 Galaxies and similar large transport aircraft, I think Elon has watched too much Thunderbirds whilst enjoying a smoke.

 

The technology is possible to design a space plane, one that can take off from a runway, go up to altitude and then unleash it's power to rise out of the atmosphere into orbit then return like the Space Shuttle but a powered landing giving even more flexibility.  For some reason though all these companies are wedded to rockets which have so many drawbacks.

 

[Reorte]

Methane has some advantages as a rocket fuel over hydrogen. The cooling requirements are significantly easier to manage, and although it's not as energy dense by mass it is denser by volume; the first stage would've needed to be even larger to use hydrogen, requiring more tank mass, structurally harder to make (with a corresponding mass increase), and increased atmospheric drag in the lower atmosphere. The first stage of the Saturn V was kerosene and oxygen for the same reason, with the second stage being a hydrogen / oxygen rocket. The practical downside of methane as a fuel is apparently it's rather more complicated to get working when both the propellant and oxidiser have similar boiling points.

 

As for space planes, do you sink a lot of money in to developing something no-one's got working, or a take an approach with a long track record of getting things in to space? Space planes are inevitably going to be something of a compromise, carrying the part needed to get through the thick part of the atmosphere with them all the way in to orbit (so less room for payload), but conversely being able to make use of the atmosphere both to save having to carry oxygen there and to make use of lift and reaction mass. So a considerably more complex beast. The approach taken by the sadly-failed Virgin Orbital is one way of trying to get some of the best of both worlds, although it'll always be limited in payload compared to a dedicated heavy rocket.

[ERIC ALLTORQUE]

Good grief,look at the lumps flying out just after lift off

 

Edited April 26, 2023 by ERIC ALLTORQUE

[woodenhead]

6 minutes ago, ERIC ALLTORQUE said:

Good grief,look at the lumps flying out just after lift off

 

Makes you wonder what could have happened if that concrete had led to a catastrophic failure.

 

I've read it was Musk who decided against tried and tested designs for the launch pad leading to something that was not up to the 'let stick as many rocket motors as we can on the bottom' approach.  Without this, it was a 50/50 launch, this could have been a disaster.

 

There are decades of experience in getting rockets to go up, it shouldn't need to be like this - coming down and landing I grant is a new challenge, but going up, NASA, the CCCP and others are pretty experienced.

[ERIC ALLTORQUE]

3 hours ago, woodenhead said:

Lovely to see SpaceX adding to the greenhouse gases with each test of a rocket solution that looks out of the 1950s.

 

Ok, so it is clever to use a lot of engines and some of the elements can land themselves, not all do as payload determines whether a reusable rocket or a single use rocket is used.  But, these monsters burn methane, the Space Shuttle used oxygen and hydrogen, why does SpaceX have to rely on something we want less off?

 

Then there is the whole idea of rockets themselves, SpaceX even touted the idea of using them as transport craft on intercontinental trips - yes in place of C5 Galaxies and similar large transport aircraft, I think Elon has watched too much Thunderbirds whilst enjoying a smoke.

 

The technology is possible to design a space plane, one that can take off from a runway, go up to altitude and then unleash it's power to rise out of the atmosphere into orbit then return like the Space Shuttle but a powered landing giving even more flexibility.  For some reason though all these companies are wedded to rockets which have so many drawbacks.

 

The lifting ability is what we are needing and powered flight in space,planes have thrust measured in thousands of pounds,rocket engines have thrust measured in tons,this booster had 7.5 thousand tons of lifting force,it weighed 5 thousand tons on lift off,it has a payload of 150 tons to orbit.

[ERIC ALLTORQUE]

4 minutes ago, woodenhead said:

Makes you wonder what could have happened if that concrete had led to a catastrophic failure

It caused the loss,we learn from failure and get complacent with success,without the space program we would not know as much about our planet or the enviromental issues we face.

The planet does not need saving,its had far worse in the 4.5 billion years its been here,its mankinds future or we die out on the planet.

[ERIC ALLTORQUE]

 

[woodenhead]

The human race will not be saved by going out into space, the rest of the universe is rushing away from us at the speed of light.

 

Until someone comes up with a method of breaking the laws of physics we are stuck in our own solar system, synthetic AI are likely to be the only ones escaping the Earth to another solar system.

 

We cannot survive on other planets, so any idea of colonising Mars beyond small laboratories is fallacy, it's a rich man's dream to get richer.

[Reorte]

18 minutes ago, woodenhead said:

The human race will not be saved by going out into space, the rest of the universe is rushing away from us at the speed of light.

 

Until someone comes up with a method of breaking the laws of physics we are stuck in our own solar system, synthetic AI are likely to be the only ones escaping the Earth to another solar system.

 

We cannot survive on other planets, so any idea of colonising Mars beyond small laboratories is fallacy, it's a rich man's dream to get richer.

Well I'm not the most enthusiastic about technology and modernity in general but even I realise that going in to space has already given us a lot of benefits even in our day to day lives - the humble weather forecast for example makes a great deal of use of satellite data. You mentioned greenhouse gases, yet without all those Earth-monitering satellites we'd be rather short of data and understanding about those impacts.

 

As for a rich man's dream to get richer, the same was true for oceanic voyages in former centuries, yet the laid the foundation of the world today. You can legitimately claim a lot of bad came from that, but so did a lot of good.

 

In any case whilst humanity's certainly got its downsides the urge to explore and understand as much of the universe as we can is one of our admirable and positive traits IMO, even if we'll never be able to do more than the tiniest part in person.

Edited April 26, 2023 by Reorte

[woodenhead]

6 minutes ago, Reorte said:

Well I'm not the most enthusiastic about technology and modernity in general but even I realise that going in to space has already given us a lot of benefits even in our day to day lives - the humble weather forecast for example makes a great deal of use of satellite data. You mentioned greenhouse gases, yet without all those Earth-monitering satellites we'd be rather short of data and understanding about those impacts.

 

As for a rich man's dream to get richer, the same was true for oceanic voyages in former centuries, yet the laid the foundation of the world today. You can legitimately claim a lot of bad came from that, but so did a lot of good.

 

In any case whilst humanity's certainly got its downsides the urge to explore and understand as much of the universe as we can is one of our admirable and positive traits IMO, even if we'll never be able to do more than the tiniest part in person.

I get scientific research and near space exploration, it's this fallacy of living on Mars will be something anybody can do.

 

It goes with self driving cars by 2019, solar panels baked into roof tiles and rigid submersibles in tight flooded caves.  They are all vehicles to make him richer whilst taking money off the US Government and investors who buy into his fantasies.  Don't get me started on the rings of satelites for his internet revolution - wait till one collides with something and we watch in awe as he creates a complete blackout on future exploration because we cannot leave the planet anymore.

[57xx]

4 hours ago, woodenhead said:

Lovely to see SpaceX adding to the greenhouse gases with each test of a rocket solution that looks out of the 1950s.

 

1950s? That's quite generous, when ever I see Starship, it reminds me of the 1930s

 

4 hours ago, woodenhead said:

Ok, so it is clever to use a lot of engines and some of the elements can land themselves, not all do as payload determines whether a reusable rocket or a single use rocket is used.  But, these monsters burn methane, the Space Shuttle used oxygen and hydrogen, why does SpaceX have to rely on something we want less off?

 

He's burning off the methane, so there will be less of it. Whilst the shuttle RS25s where using LOX/Hydrogen, they only provided 15% of the take off thrust. The main thrust came from the SRBs which used aluminium for fuel. Not really clean burning.

 

4 hours ago, woodenhead said:

Then there is the whole idea of rockets themselves, SpaceX even touted the idea of using them as transport craft on intercontinental trips - yes in place of C5 Galaxies and similar large transport aircraft, I think Elon has watched too much Thunderbirds whilst enjoying a smoke

 

 

The arse first landings of starship do remind me of Gerry Anderson productions.

 

4 hours ago, woodenhead said:

The technology is possible to design a space plane, one that can take off from a runway, go up to altitude and then unleash it's power to rise out of the atmosphere into orbit then return like the Space Shuttle but a powered landing giving even more flexibility.  For some reason though all these companies are wedded to rockets which have so many drawbacks.

 

 

SSTO sucks. I quit the other video at around 4 minutes when he mentioned throwing spaghetti at the walls. He is clearly too idle to research just how many rockets went bang when NACA/NASA were trying to get things right in the 50s/60s.

 

[57xx]

1 hour ago, woodenhead said:

Makes you wonder what could have happened if that concrete had led to a catastrophic failure.

 

 

Ummm, it did. 😂

 

1 hour ago, woodenhead said:

I've read it was Musk who decided against tried and tested designs for the launch pad leading to something that was not up to the 'let stick as many rocket motors as we can on the bottom' approach.  Without this, it was a 50/50 launch, this could have been a disaster.

 

 

Yup, apparently he tweeted a few years back that he was desperately trying to avoid using a flame trench. Why, I have no clue. He just need to do some research into the history of rocketry to see why they are used. I saw lots of fanboys defending the decision saying they couldn't dig down due to the water table, they couldn't build a mound for "reasons".  Hmm, so Merritt Island isn't some large flat expanse of land with a water table a couple of feet down then? This is stuff that was done 6 decades ago.

[ERIC ALLTORQUE]

1 hour ago, woodenhead said:

The human race will not be saved by going out into space, the rest of the universe is rushing away from us at the speed of light

Check out Andromeda,its heading straight for us.

[Ozexpatriate]

4 minutes ago, 57xx said:

... apparently he tweeted a few years back that he was desperately trying to avoid using a flame trench. Why, I have no clue.

I understood that it was related to 'reusability'-related concerns, though these seem more compelling to me regarding Starship HLS-B, rather than Stage 0, where Starship will be expected to launch without *any* pad facilities (from the lunar surface, for example in future Artemis profiles like Artemis IV). 

[57xx]

17 minutes ago, Ozexpatriate said:

I understood that it was related to 'reusability'-related concerns, though these seem more compelling to me regarding Starship HLS-B, rather than Stage 0, where Starship will be expected to launch without *any* pad facilities (from the lunar surface, for example in future Artemis profiles like Artemis IV). 

 

Yes, I've seen the Starship reasoning as well. Where that falls down for me is 3 vacuum optimised Raptors vs 33 sea level Raptors. That is a BIG difference in thrust, especially with only 17% gravity too.

[Flying Pig]

1 hour ago, 57xx said:

 

Yes, I've seen the Starship reasoning as well. Where that falls down for me is 3 vacuum optimised Raptors vs 33 sea level Raptors. That is a BIG difference in thrust, especially with only 17% gravity too.

 

Is it such a big difference in exhaust velocity?  It only takes one chunk of regolith to damage something vital. 

[Jeff Smith]

4 minutes ago, Flying Pig said:

 

Is it such a big difference in exhaust velocity?  It only takes one chunk of regolith to damage something vital. 

Well hopefully the landing will have cleared away all the loose stuff on the Moon or Mars with a relatively slow decent.  The astronauts can also clear the site if necessary!

[Flying Pig]

2 minutes ago, Jeff Smith said:

Well hopefully the landing will have cleared away all the loose stuff on the Moon or Mars with a relatively slow decent.  The astronauts can also clear the site if necessary!

 

Some thoughts:

• damage could also occur during landing;
• moving loose material away, possibly out of a crater formed on landing, while wearing spacesuits is going to be extermely difficult and taxing;
• the damage the other day was caused by material not previously considered to be loose.

[57xx]

23 minutes ago, Flying Pig said:

Is it such a big difference in exhaust velocity?  It only takes one chunk of regolith to damage something vital. 

 

Velocity no, I don't think so, but the diameter of the nozzle is much wider so the thrust is spread across a wider area.  You also have 1/10th of the total thrust just by virtue of the number of engines and to get off the moon, I doubt very much they would have to throttle up to 100% with 17% of Earth gravity. 

 

Also remember, we've done this 5 times before (albeit on a smaller scale). One of the claims of the tin foil hat brigade is that there would have been a crater under the LEM when it landed because they imagine a massive roaring rocket trying to lift 10000s of tons off Earth. There is much less thrust required, spread over a bigger area and no air to kick up dust. Oh yes, and talking of no air, that means the exhaust can spread out beyond the width of the nozzle, further reducing the pressure on the surface. Think of the rocket first stage, at launch, you have columns of exhaust from each engine, as it ascends, you see the exhaust flaring out - this is because as the air gets thinner higher up, there is less pressure to constrain the exhaust. That's why you have different engine nozzles for air or vacuum optimised for each environment.

[Flying Pig]

1 hour ago, 57xx said:

Also remember, we've done this 5 times before (albeit on a smaller scale).

 

Strictly, we haven't as the LEM used a separate ascent engine which wasn't exposed during landing. 

 

There is research on interaction of rocket plumes with the surfaces of different bodies:

 

https://sciences.ucf.edu/class/landing-team/background/