The rocket stages are different. For example, a hydrogen-oxygen stage with a turbopump closed cycle engine is very different from a kerosene-peroxide stage with a pressure-fed engine. The second option is to make the SSTO almost impossible without the initial acceleration and the water stage is the best option for this.
It was concluded that LAS can be used both as booster as well as a first stage for an orbital rocket, providing a boost of their payload weight with up to 30%, or make the current rockets use 25% less polluting propellant.
Quote from: Redclaws on 07/23/2021 10:20 pmQuote from: Beratnyi on 07/23/2021 10:05 pmQuote from: joek on 07/23/2021 08:35 pmQuote from: Beratnyi on 07/23/2021 08:13 pmThe ARCA approach is very smart for the following reasons:1) This makes it very easy to make an SSTO, since it is not entirely correct to take into account the water stages2) Water stages are actually cheap analogs of non-rocket launch systems such as space cannon, spin launch, hypersonic air launch, etc....Stages are stages, regardless of the technology. The "water stages" are stages. This is not, nor will ever be, SSTO any more than Virgin Orbit would be considered SSTO (assuming they could get to a single stage). Get rid of the "water stages" and you might have an SSTO argument; otherwise not.Think of this as a task of using electricity for the initial overclocking of the SSTO. This can be done in several ways:1) Use a complex, expensive and ineffective electromagnetic cannon to fire a rocket with large overloads2) Use a centrifuge to spin the rocket to a crazy rotation and launch, again with large overloads3) Use an ultra-expensive array of lasers to heat the propellant in the rocket tank4) Use an electric supersonic aircraft for air launch, which is still pure fantastic5) Use a composite tank with water heated to 250C and under a pressure of 40 atmospheres. After starting, lower the tank by parachute, refill with water and use againI think it becomes obvious which way is the smartest.Ok, but……. It’s a stage. It’s literally a set of tanks full of something used to propel the rocket which is dropped while other parts of it continue.The rocket stages are different. For example, a hydrogen-oxygen stage with a turbopump closed cycle engine is very different from a kerosene-peroxide stage with a pressure-fed engine. The second option is to make the SSTO almost impossible without the initial acceleration and the water stage is the best option for this.
Quote from: Beratnyi on 07/23/2021 10:05 pmQuote from: joek on 07/23/2021 08:35 pmQuote from: Beratnyi on 07/23/2021 08:13 pmThe ARCA approach is very smart for the following reasons:1) This makes it very easy to make an SSTO, since it is not entirely correct to take into account the water stages2) Water stages are actually cheap analogs of non-rocket launch systems such as space cannon, spin launch, hypersonic air launch, etc....Stages are stages, regardless of the technology. The "water stages" are stages. This is not, nor will ever be, SSTO any more than Virgin Orbit would be considered SSTO (assuming they could get to a single stage). Get rid of the "water stages" and you might have an SSTO argument; otherwise not.Think of this as a task of using electricity for the initial overclocking of the SSTO. This can be done in several ways:1) Use a complex, expensive and ineffective electromagnetic cannon to fire a rocket with large overloads2) Use a centrifuge to spin the rocket to a crazy rotation and launch, again with large overloads3) Use an ultra-expensive array of lasers to heat the propellant in the rocket tank4) Use an electric supersonic aircraft for air launch, which is still pure fantastic5) Use a composite tank with water heated to 250C and under a pressure of 40 atmospheres. After starting, lower the tank by parachute, refill with water and use againI think it becomes obvious which way is the smartest.Ok, but……. It’s a stage. It’s literally a set of tanks full of something used to propel the rocket which is dropped while other parts of it continue.
Quote from: joek on 07/23/2021 08:35 pmQuote from: Beratnyi on 07/23/2021 08:13 pmThe ARCA approach is very smart for the following reasons:1) This makes it very easy to make an SSTO, since it is not entirely correct to take into account the water stages2) Water stages are actually cheap analogs of non-rocket launch systems such as space cannon, spin launch, hypersonic air launch, etc....Stages are stages, regardless of the technology. The "water stages" are stages. This is not, nor will ever be, SSTO any more than Virgin Orbit would be considered SSTO (assuming they could get to a single stage). Get rid of the "water stages" and you might have an SSTO argument; otherwise not.Think of this as a task of using electricity for the initial overclocking of the SSTO. This can be done in several ways:1) Use a complex, expensive and ineffective electromagnetic cannon to fire a rocket with large overloads2) Use a centrifuge to spin the rocket to a crazy rotation and launch, again with large overloads3) Use an ultra-expensive array of lasers to heat the propellant in the rocket tank4) Use an electric supersonic aircraft for air launch, which is still pure fantastic5) Use a composite tank with water heated to 250C and under a pressure of 40 atmospheres. After starting, lower the tank by parachute, refill with water and use againI think it becomes obvious which way is the smartest.
Quote from: Beratnyi on 07/23/2021 08:13 pmThe ARCA approach is very smart for the following reasons:1) This makes it very easy to make an SSTO, since it is not entirely correct to take into account the water stages2) Water stages are actually cheap analogs of non-rocket launch systems such as space cannon, spin launch, hypersonic air launch, etc....Stages are stages, regardless of the technology. The "water stages" are stages. This is not, nor will ever be, SSTO any more than Virgin Orbit would be considered SSTO (assuming they could get to a single stage). Get rid of the "water stages" and you might have an SSTO argument; otherwise not.
The ARCA approach is very smart for the following reasons:1) This makes it very easy to make an SSTO, since it is not entirely correct to take into account the water stages2) Water stages are actually cheap analogs of non-rocket launch systems such as space cannon, spin launch, hypersonic air launch, etc....
Quote from: Beratnyi on 07/23/2021 11:08 pmThe rocket stages are different. For example, a hydrogen-oxygen stage with a turbopump closed cycle engine is very different from a kerosene-peroxide stage with a pressure-fed engine. The second option is to make the SSTO almost impossible without the initial acceleration and the water stage is the best option for this.You are not talking about SSTO, but what types of stages are more efficient-effective. ARCA architecture is not SSTO, and will never be SSTO. Per ARCA (emphasis added):Quote from: ARCAIt was concluded that LAS can be used both as booster as well as a first stage for an orbital rocket, providing a boost of their payload weight with up to 30%, or make the current rockets use 25% less polluting propellant.By any reasonable definition, those are stages and involve staging events.Strongly suggest you discontinue the SSTO argument, or take it to another forum.
Also, I do not consider the Boeing 747 to be the first stage of the LauncherOne rocket. This is a terminology debate.
The EcoRocket launch is rescheduled for the second half of September as we are still waiting to receive the flight clearance paperwork from the aeronautical authorities. Meanwhile, the team is taking the opportunity to perform more ground tests on the launch system.
I thought the upper stages were supposed to be something other than the water bottle rockets?
Quote from: Davidthefat on 09/02/2021 05:25 pmI thought the upper stages were supposed to be something other than the water bottle rockets?Just the upper stage.
Yes, it is easy to be accused of snarkiness when so many promises have been made and I can't think of a single one ARCA has delivered that met my clearly subjective approval. This got me thinking that ARCA makes a really good test subject for creating a rating system across launch providers measuring promises made, in hardware, schedule, and budget, and comparing these to actual deliveries. It is admirable to treat developers fairly, and fairly includes a thorough record of promises vs. deliveries, or lack thereof. Unfortunately this fairness can also be mistaken for tacit approval, which could be used to misguide investors. You shouldn't have to read 20 pages of posts about goalposts announced and moved in order to develop your impression, it should be summarized. Having this in a table encourages facts and should include metrics that can then be applied to others in the industry. I for one wouldn't mind an actual value for calculating Elon Time.
Quote from: AJW on 09/07/2021 06:27 pmYes, it is easy to be accused of snarkiness when so many promises have been made and I can't think of a single one ARCA has delivered that met my clearly subjective approval. This got me thinking that ARCA makes a really good test subject for creating a rating system across launch providers measuring promises made, in hardware, schedule, and budget, and comparing these to actual deliveries. It is admirable to treat developers fairly, and fairly includes a thorough record of promises vs. deliveries, or lack thereof. Unfortunately this fairness can also be mistaken for tacit approval, which could be used to misguide investors. You shouldn't have to read 20 pages of posts about goalposts announced and moved in order to develop your impression, it should be summarized. Having this in a table encourages facts and should include metrics that can then be applied to others in the industry. I for one wouldn't mind an actual value for calculating Elon Time.So many people who are trying to do things without enough money get into the trap of either not promising enough - not being ambitious enough to raise any interest - or promising too much. The more you work on trying to do new things the more you will realise how difficult it is. That's why I find their changes of date etc quite understandable. I probably wouldn't invest a lot of money in them - and that's the highest judgement one can ultimately make as an individual - but do I wish them (and all spaceflight dreamers) a break, luck, success. Putting people down just doesn't seem like "the way".
Quote from: t43562 on 09/08/2021 08:13 amQuote from: AJW on 09/07/2021 06:27 pmYes, it is easy to be accused of snarkiness when so many promises have been made and I can't think of a single one ARCA has delivered that met my clearly subjective approval. This got me thinking that ARCA makes a really good test subject for creating a rating system across launch providers measuring promises made, in hardware, schedule, and budget, and comparing these to actual deliveries. It is admirable to treat developers fairly, and fairly includes a thorough record of promises vs. deliveries, or lack thereof. Unfortunately this fairness can also be mistaken for tacit approval, which could be used to misguide investors. You shouldn't have to read 20 pages of posts about goalposts announced and moved in order to develop your impression, it should be summarized. Having this in a table encourages facts and should include metrics that can then be applied to others in the industry. I for one wouldn't mind an actual value for calculating Elon Time.So many people who are trying to do things without enough money get into the trap of either not promising enough - not being ambitious enough to raise any interest - or promising too much. The more you work on trying to do new things the more you will realise how difficult it is. That's why I find their changes of date etc quite understandable. I probably wouldn't invest a lot of money in them - and that's the highest judgement one can ultimately make as an individual - but do I wish them (and all spaceflight dreamers) a break, luck, success. Putting people down just doesn't seem like "the way".Your comments would be well-founded if directed at many of the small, underfunded and overworked firms who are genuinely trying to develop space hardware.However, these people are not doing that. They are not developing an LV; they are seeking funding for a so-called 'design' that is complete nonsense. Any delays merely stretch out their window of opportunity without having to prove anything (while putting out the odd update such as the video above).Like any good con, it passes a few very casual tests; e.g. they have a tube-shaped thing that looks a bit like a rocket, and yes, thrust can be generated by ejecting steam through a nozzle.However, there are many other points that show this to be complete codswallop, the simplest of which doesn't require you to believe me, or anyone else on this forum.Just look at a set of steam tables. Starting with a tank of hot water doesn't get you very far.
There must be a lot of ways to "con" people that are easier and a lot more profitable than this one - why not just start another pyramid scam? I think it would add to the "case" to have some evidence. I see they ask for "donations" on their website - so the people who do that know they're getting nothing back from the outset. Seems quite honest to me.
Why now is the best time to invest in ARCA Space Corporation:The stock price is now $201.35/share. After the launch of the Demonstrator 3 rocket, the stock has a high chance of gaining value, but will not lose value, regardless of the outcome.If the launch is successful, we will perform a new evaluation of our company's registered value, which is expected to double. This would benefit all shareholders, and is consistent with our goal to increase our company's value ten fold by 2019. Therefore, this will also increase the price of our stock. Any failures encountered during launch will not result in a loss of stock value, as we are a well established company.
