Rocket 4 to have a new, bigger engine, with no details.
aiming for high reliability but not 100%
Very interesting how they have the totally opposite view to Relativity when it comes to 3D printing. Kemp says 3D printing is the worst possible approach to take if you want to mass produce something at low cost.Relativity, by contrast, want to 3D print absolutely evertything.
Quote from: M.E.T. on 06/06/2021 04:59 amVery interesting how they have the totally opposite view to Relativity when it comes to 3D printing. Kemp says 3D printing is the worst possible approach to take if you want to mass produce something at low cost.Relativity, by contrast, want to 3D print absolutely evertything.The car industry doesn't 3D parts for their mainstream cars.Sent from my SM-G570Y using Tapatalk
He is absolutely right about 3D printing. I've worked quite bit with metal printing especially, and while it looks shiny there are no good reasons to use it outside of one-off prototyping or very specific specialized parts that can't be made any other way where cost is no criteria.If you think about the taxonomy of manipulating material, you go from bending and riveting through cutting and welding to machining and casting. You spend a bit more energy and wast material at each stage for a bit more capability. 3D printing is at the very extreme end of this scale. You literally grind the material down into tiny particles and rebuild and melt every bit of it from scratch.Not only does this use pretty much the highest possible amount of energy to build a given part, the melting process also vaporizes about 50% of the material and wastes it into the air outlet filter. You also have constraints on material selection which is inconvenient considering you'd use it for especially high performing parts.If you can cast the part instead of printing it, you save the material without increasing energy use. If you can machine it, you use far less energy but still waste some material. For something like a tank, both are far too complex. Bending and welding sheets, hoops and stringers is dirt cheap not just because it is simple and reliable technology, but also from a first principles point of view regarding material and energy cost that you can't get past regardless of technological development.
Quote from: niwax on 06/06/2021 02:25 pmHe is absolutely right about 3D printing. I've worked quite bit with metal printing especially, and while it looks shiny there are no good reasons to use it outside of one-off prototyping or very specific specialized parts that can't be made any other way where cost is no criteria.If you think about the taxonomy of manipulating material, you go from bending and riveting through cutting and welding to machining and casting. You spend a bit more energy and wast material at each stage for a bit more capability. 3D printing is at the very extreme end of this scale. You literally grind the material down into tiny particles and rebuild and melt every bit of it from scratch.Not only does this use pretty much the highest possible amount of energy to build a given part, the melting process also vaporizes about 50% of the material and wastes it into the air outlet filter. You also have constraints on material selection which is inconvenient considering you'd use it for especially high performing parts.If you can cast the part instead of printing it, you save the material without increasing energy use. If you can machine it, you use far less energy but still waste some material. For something like a tank, both are far too complex. Bending and welding sheets, hoops and stringers is dirt cheap not just because it is simple and reliable technology, but also from a first principles point of view regarding material and energy cost that you can't get past regardless of technological development.You forgot to add quality control of material in end product. With forging or sheet metal we know properties of the end product as process doesn't change it much.Additiving manufacturing means bonding lots of matetial together by heat typically laser or arch welding. The quality of each one of those bonds has to be consistant. With 3D a lot of printing R&D has gone into determining if material properties of end product are with spec. As example solid looking block of plastic we 3d printed at work on $1000 printer was porous. This wasn't by design just result of not so perfect bonding between layers.Sent from my SM-G570Y using Tapatalk
Astra to acquire spacecraft propulsion company Apollo Fusionby Jeff Foust — June 7, 2021WASHINGTON — Launch vehicle developer Astra is acquiring Apollo Fusion, a company developing electric propulsion systems for spacecraft, as part of its effort to create vertically integrated space systems.Astra is purchasing Apollo Fusion for $30 million in stock and $20 million in cash in a deal announced June 7.
https://spacenews.com/astra-to-acquire-spacecraft-propulsion-company-apollo-fusion/QuoteAstra to acquire spacecraft propulsion company Apollo Fusionby Jeff Foust — June 7, 2021WASHINGTON — Launch vehicle developer Astra is acquiring Apollo Fusion, a company developing electric propulsion systems for spacecraft, as part of its effort to create vertically integrated space systems.Astra is purchasing Apollo Fusion for $30 million in stock and $20 million in cash in a deal announced June 7.
ASTRA & APOLLO: REACHING NEW ORBITS TOGETHERJUNE 7, 2021By: Benjamin LyonToday, we announced that Astra will acquire Apollo Fusion. This acquisition enables Astra to efficiently deliver and operate throughout our solar system, and brings incredible technology and talent into our team.So, what is this all really about? At Astra we’re focused on rapid and affordable access to space. This really requires two kinds of transportation: You always have to first fly from Earth to a low orbit on the edge of space, and Astra shines in getting you to the best possible low orbit for your mission. However, often you need to keep going — to fly higher in space for your operational mission. And this is where Apollo comes in.Let’s dig into this a bit. When flying from the ground to space, you need powerful, high-thrust engines to overcome gravity and push the vehicle with its payload through the atmosphere at an ever-increasing speed. This requires a LOT of thrust and consumes a huge amount of fuel. (Typically, 90% of more of the weight of a rocket ready to lift off is fuel) Once you get to space and are in a low orbit, the spacecraft is floating in zero gravity, so you can use very small forces to move around. This is analogous to a getting a boat into a lake – it’s very heavy to lift and carry it on the ground, but light paddling will move it easily once it’s in the water.This “paddling” is where electric propulsion (EP) systems come into play in space. Harnessing the power of the sun, they use electricity to accelerate a very small flow of inert gas to high speed, producing a constant, low thrust that is highly efficient. The high efficiency allows a spacecraft to slowly but continuously accelerate, which moves it to a higher and higher orbit. This makes EP an excellent solution for going from low earth orbits to medium, high, or geostationary orbits, and even to the moon or beyond!We chose Apollo Fusion because they had developed a best-in-class EP system that is cost-effective and reliable, at scale. Apollo’s design cycles are measured in months, not years, and their solutions are both easy to manufacture and to assemble. They don’t see their job as done when they have something that initially works. Apollo continues to optimize for manufacturability and scalability.Astra has purposefully drawn its talent from beyond the aerospace industry, and bringing the best practices from tech, automotive, services and other industries has been a key element to our rapid progress to date. Apollo Founder and CEO, Mike Cassidy, shares the same belief in the value diverse skill sets bring. He has both the understanding and experience of how bring consumer technologies like high performance, low power processing to aerospace, with team members from companies such as SpaceX, Google, Tesla and Apple. Their deep expertise is important too: Apollo team members have contributed to over 2,000 satellites in orbit today. Their culture shares Astra’s focus on maximizing development velocity, designing for scale, and passion about the opportunity that space creates.We are delighted to welcome the Apollo Fusion team into the Astra team! I’m excited to see what we do together.Ad Astra!-B
They will need to spend it fast
Quote from: ringsider on 06/07/2021 12:48 pmThey will need to spend it fast No they don't. The whole point of a SPAC is they get an immediate lump-sum cash injection with very minimal strings attached (i.e. no jumping through the hoops of an IPO) and no debt to repay. The post-acquisition stock price tanking makes further investment funding rounds unlikely and annoys employees expecting large share option payouts (and means investors in the initial SPAC make out poorly), but does not mean Astra's existing funding suddenly vanishes. That cash is in the bank.It's prudent to spend what they have to accelerate development - as their R&D is paid for by past income rather than future debt, penny-pinching and stretching development time to reduce total R&D outlay is not an optimal strategy - but not mandatory.
Update on @Astra’s process of going public - our S-4 is now effective with the SEC. We will start mailing proxy statements today for shareholders of $HOL to vote ahead of the shareholder meeting on 6/30. We intend to start trading on @Nasdaq as $ASTR on 7/1!
https://twitter.com/kemp/status/1401908302305320961QuoteUpdate on @Astra’s process of going public - our S-4 is now effective with the SEC. We will start mailing proxy statements today for shareholders of $HOL to vote ahead of the shareholder meeting on 6/30. We intend to start trading on @Nasdaq as $ASTR on 7/1!