We could see an orbital launch of SpaceX’s Starship this year
universetoday.com
universetoday.com
"The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes. For example, cracks have been found in the turbine blades of the high pressure oxygen turbopump. Are they caused by flaws in the material, the effect of the oxygen atmosphere on the properties of the material, the thermal stresses of startup or shutdown, the vibration and stresses of steady running, or mainly at some resonance at certain speeds, etc.? How long can we run from crack initiation to crack failure, and how does this depend on power level? Using the completed engine as a test bed to resolve such questions is extremely expensive. One does not wish to lose an entire engine in order to find out where and how failure occurs. Yet, an accurate knowledge of this information is essential to acquire a confidence in the engine reliability in use. Without detailed understanding, confidence can not be attained.
"A further disadvantage of the top-down method is that, if an understanding of a fault is obtained, a simple fix, such as a new shape for the turbine housing, may be impossible to implement without a redesign of the entire engine."
But I still believe in the headline. They're building a new prototype every 2 weeks, and they currently have 3 prototypes stacked. This in an industry which usually takes years to build a single prototype. Their velocity is insane.
Version 2 [0] has a diameter of 18m and an astonishing payload.
Whilst V1 will change space launches forever. I think that V2 will become the most versatile of space vehicles. The capacity so large that it would be able to launch a copy of the ISS by itself. [1].
I think V2 will usher in new capabilities of manufacturing in space, space mining on asteroids and off worlds, interstellar way stations (planet hopping across the solar system) and the ability to launch a global coverage of Starlinks in 1 launch instead of 24 falcon 9 launches [2].
So yes, while V1 changes the game and puts SpaceX at the forefront of space and rockets. Once they turn their attention on V2 and that launches. Absolutely everything changes and true infrastructures can then be built and once an infrastructure to the end of the solar system occurs. We can only imagine what humanity looks like.
[0]: https://www.reddit.com/r/SpaceXLounge/comments/cwurkj/update...
[1]: https://www.reddit.com/r/SpaceXLounge/comments/cy4lno/18m_st...
[2]: https://spacenews.com/spacex-plans-to-start-offering-starlin...
A new engine was needed because while the Merlin is a great engine, it could never be reused the thousands of times Raptor is designed to be reused. You can think of engine design as the simultaneous, interdependent optimization across 10+ dimensions, but as an example of one of dimensions - Raptor uses Methane (rather than Kerosene) because it burns cleaner (does not leave residue) and can be manufactured on Mars more easily. Here's an in-depth video about Raptor: https://www.youtube.com/watch?v=LbH1ZDImaI8
The rest of the rocket is similar, in that it is done with manufacturability, reusability and scale in mind. The Falcon design could never stretch to these demands.
- Falcon doesn't have a reusable second stage. Starship's second stage is reusable. Starship should be more cost efficient because of this.
- Falcon doesn't have the capacity to carry enough humans and cargo to Mars. It is a trip that can take upwards of half a year. Starship can supposedly carry 100 people and 100 tons of cargo. Falcon with Crew Dragon can only carry 7 people a few days.
- Starship is designed to be able to enter Mars atmosphere. Its skin is stainless steel and some heat shielding. The stainless steel can survive much higher temperatures which means less heat shielding. Falcon is aluminum and would require more heat shielding.
- Falcon has fuel tanks for its Merlin engines that use rocket fuel (RP-1?) and oxygen. The tanks are a specific size for the burn ratios. The rocket fuel can't be readily made on Mars and its mass makes it infeasible to carry enough fuel for a return. Starship's engines (Raptor) use methane and oxygen. Methane can be readily made on Mars. Changing Falcon from Merlin to Raptor engines would mean redesigning the tanks to have different sizes.
Given all this, it makes more sense to design a new rocket than trying to redesign the existing one.
Coincidence?
"Need" is interesting. There are two key goals with the Raptor engine. #1- Switch to Methane burning. Methane is available much more easily everywhere in the solar system- Mars especially. So we can make fuel wherever we are instead of bringing it. #2- Make it much more resilient to re-use. Those Merlin engines are great, but they need a lot of work to get them ready to go again. Lots of inspection. Raptor is a Full-flow staged combustion engine[0]. Everyday Astronaut does a great write-up (and video) on the topic[1].
> why they didn't just iterate on the Falcon design and what necessitates a "full stack" clean slate approach
Falcon is big, but it isn't huge. It's got a 3.7m diameter. Starship has a 9m diamater, almost 2 and a half times wider (meaning more than 5 times larger circumference). When you scale up that much, you're basically starting over.
This size increase also means Starship should be able to lift something like 6 times more to orbit. And because it's so huge, it won't need a booster to launch itself from Mars or the Moon.
Materials also matter. Falcon is made of carbon fiber: carbon fiber is expensive and hard to work with. It's slow. Iteration is slow. If you want to blow up 1 rocket per month in testing, that's going to get expensive and take a lot of work to make happen, especially given the larger size. Steel, on the other hand, is cheap and fast. So Starship is based on steel.
Starship is also fully reusable. Falcon 9 isn't- the second stage is expended. They looked into how they might bring those back, but it just wasn't worth the R&D effort.
When it's all done, Starship is going to be a fully-reusable system that is cheap to build, cheap/easy to operate, can be refueled easily, anywhere (like Mars), can launch itself from the Moon or Mars without a booster. It will be cheaper to launch per kg than any other launch system out there by probably an order of magnitude. It will dominate the competition and likely claim a monopoly on the private launch market until someone gets their shit together and competes.
[0]https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-f...
Falcon's walls and domes are made of aluminum-lithium alloy. They do have a tiny bit of carbon fiber; for example they have composite overwrapped pressure vessels (COPV) containing helium for pressurization.
The Starship design decisions all come from that goal.
- big
- rapidly and fully reusable
- fuel that can be synthesized on Mars
Starship is not an SSTO and is not expected to reach orbit on its own.
To do an orbital flight they'll need to also develop Super Heavy. That's not too crazy because Super Heavy is a stretched Starship, but it will take some time.
So it technically is a (not very useful) SSTO. But is enough for it to be tested in orbit before Super Heavy is ready.
Although come to think of it I don't know if fuel issues would prevent it from being able to land with a full complement of rescued astronauts.
This all means that when Hans talks about an orbital flight in 6+ months, he must be talking about flying it with Super Heavy.
Still, spacex has been signaling that they want to get this (orbital starship) done this year. With the moon contacts depending on convincing progress I think it's plausible that they will push hard enough to make it - if things go well (stop exploding sooner rather than later) at least.
Starship development iterations are going crazy fast, but to reach orbit they'll also need Super Heavy.
Haven't been keeping up on the development lately, but I believe SpaceX is yet to start building a SH prototype.
https://en.wikipedia.org/wiki/SM-65_Atlas#/media/File:USAF_I...
I don't really follow along much I was surprised to read so many had exploded. What I didn't see was how do we know when they've stopped exploding? I guess I mean, how many successes would be enough to say "well these are done exploding now"? This year is 1/2 done, are they really able to say that these are safe in just 6 months?
The stuff breaking right now isn't really representative of the final product, it's more like problems in ramping up the manufacturing. And the nice thing about reusable rockets is that you can test them much more thoroughly than if you throw them away after each flight.
SN4 didn't really fail any tests. It was the fault of the disconnect. SN5 was supposed to be moved to the test pad today but there may be a delay.
The first one lit on fire and crashed at T+41. On the second flight, the first stage bashed into the second stage during stage separation and the second stage lost control. On the third flight, the first stage bashed into the second stage and the second stage didn't get to orbit.
The videos are all on youtube, you can watch and observe the lack of explosions.
Maybe 'blew up' means something different to you than it does to me, but to me it means there was an explosion.
It was fully ready design, where they caught last issues in the integration stage.
Starship is right now at the state of someone doodling in their notebook.