Starship and a Human city on Mars

[Carl Sagan]

Ten minutes to launch!

Roughly. There isn't a set time. Could even be sooner. The official feed (4:30 CST is 22:30 GMT):

 

Edited December 8, 2020 by Carl Sagan

[Carl Sagan]

Aborted! The Raptor engines automatically shut down  with 1 second to go (reason unknown). Presume we go again tomorrow. 

[Carl Sagan]

We're trying again tonight, but in case of more problems the no-fly zone above the launch site has been extended to also cover Thursday and Friday. But the tank farm (which provides the cryogenic fuel) is now active (venting fuel) and the NASA high-altitude spotter plane has filed a flightpath from Florida to Texas to observe the hoped-for launch, so hopefully tonight is the night. Not as many streams right now, but it's live here:

 

[Carl Sagan]

We're good to go at this point. The SpaceX feed is just about to go live. Launch timetabled for just after 9pm

 

[Carl Sagan]

First flight was amazing. It all lasted just a little under 7 minutes.

The first 4:45 is a vertical ascent, first on all 3 engines, then down to 2, and then a single 1. The engines cut off and the ship coasts upward a little longer and turns horizontal, preparing to "belly flop" back to Earth, falling with style, until it approaches the ground when it relights its engines and turns vertical again, ending with a controlled upright landing. Quite how any Humans onboard (and ultimately it's meant to hold 100 of us) cope with the changing orientation is yet to be seen.

Well worth watching the full video. Including the dramatic finale!

 

[Carl Sagan]

View of the "landing" from the beach: 

 

[EtoileSportiveDeDerby]

7 hours ago, Carl Sagan said:

First flight was amazing. It all lasted just a little under 7 minutes.

The first 4:45 is a vertical ascent, first on all 3 engines, then down to 2, and then a single 1. The engines cut off and the ship coasts upward a little longer and turns horizontal, preparing to "belly flop" back to Earth, falling with style, until it approaches the ground when it relights its engines and turns vertical again, ending with a controlled upright landing. Quite how any Humans onboard (and ultimately it's meant to hold 100 of us) cope with the changing orientation is yet to be seen.

Well worth watching the full video. Including the dramatic finale!

 

A couple of questions

Whats the idea behind the horizontal approach ?

why so close to the ground, it barely has time to correct itself back to a vertical position ?

 so close to the ground ? Barely has any time to correct

[Carl Sagan]

31 minutes ago, EtoileSportiveDeDerby said:

A couple of questions

Whats the idea behind the horizontal approach ?

why so close to the ground, it barely has time to correct itself back to a vertical position ?

The horizontal approach is to maximize the surface area in contact with the atmosphere. When returning from space this will help increase the air resistance to slow the rocket down and spread the heating over the widest area.

From space, especially if on an interplanetary trajectory, you are travelling *really* fast yet have to bring that speed down to zero. And you will have as little fuel as possible (because of the weight penalty). So getting close to the ground just optimizes this part of the process.

SpaceX has successfully landed more than 60 of its Falcon9 rockets from space missions, and these only relight one engine when close to the landing site, so they know that final burn can be done pretty close to the ground. 

At first this looks like a render, but it's amazing real footage! 

 

[Stive Pesley]

I posted a question early on in this thread about the effects of (the lack of gravity) on people planning to live on Mars

An interesting article here explains a little more

https://medium.com/predict/space-exploration-needs-artificial-gravity-623cbd42121

Astronauts on the ISS have serious side effects from microgravity after 6 months - and that's just the one way travel time to Mars. If Mars travellers then try to live in microgravity on Mars for a further prolonged period, it  will wreck their bodies

 

 

 

[TigerTedd]

5 hours ago, Carl Sagan said:

The horizontal approach is to maximize the surface area in contact with the atmosphere. When returning from space this will help increase the air resistance to slow the rocket down and spread the heating over the widest area.

From space, especially if on an interplanetary trajectory, you are travelling *really* fast yet have to bring that speed down to zero. And you will have as little fuel as possible (because of the weight penalty). So getting close to the ground just optimizes this part of the process.

SpaceX has successfully landed more than 60 of its Falcon9 rockets from space missions, and these only relight one engine when close to the landing site, so they know that final burn can be done pretty close to the ground. 

At first this looks like a render, but it's amazing real footage! 

 

So is it concerning that this one blew up, or was it all part of the plan? Or do we take the 1 in 90 chance when we fly on it?

[Carl Sagan]

15 minutes ago, TigerTedd said:

So is it concerning that this one blew up, or was it all part of the plan? Or do we take the 1 in 90 chance when we fly on it?

Not at all concerning. Pre-flight assessment was that it would almost certainly blow up somewhere as long the way, so to make it all the way to the landing pad and just arrive a little too fast is seen as a great success. These rockets will fly many hundreds, probably thousands of times, before they start transporting Humans. 

4 hours ago, Stive Pesley said:

I posted a question early on in this thread about the effects of (the lack of gravity) on people planning to live on Mars

An interesting article here explains a little more

https://medium.com/predict/space-exploration-needs-artificial-gravity-623cbd42121

Astronauts on the ISS have serious side effects from microgravity after 6 months - and that's just the one way travel time to Mars. If Mars travellers then try to live in microgravity on Mars for a further prolonged period, it  will wreck their bodies

Sorry to miss this. It's a great and important point. As you rightly state out microgravity (what most people think of as Zero-G) wrecks the Human body fairly quickly. One of the issues with Starship is the duration of the Mars flight, which will probably be around 5 months. Not great for then getting to work on Mars. 

There's a key unknown question which is, "what level of gravity is safe enough for Humans to live - and do things such as give birth - long term?" We do not know the answer and should be working to find out. I know some former NASA engineers who have a fantastic design for a rotating space station, which would be large enough to simulate Mars gravity (about one-third Earth). We need to start building structures like this. 

Also, I've suggested to them (and they liked the idea!) that they link two counter-rotating stations and then stick a Starship in the middle to power it, and then you have a genuine interplanetary spaceship with artificial gravity, and Bob's your uncle! Here's a video of their concept. 

 

 

[Carl Sagan]

SN8 is dead; long live SN9!

The crown passes to Serial Number 9 (the 9th prototype) which rolls out onto the test pad this coming Monday. First off will probably be pressure tests to ensure the fuel tanks are up to the job. The ship can fly if the tanks withstand 7 bar (7x atmospheric pressure) but the goal is to get them over 10 bar as that's what's required for future Human certification. 

[TigerTedd]

3 hours ago, Carl Sagan said:

SN8 is dead; long live SN9!

The crown passes to Serial Number 9 (the 9th prototype) which rolls out onto the test pad this coming Monday. First off will probably be pressure tests to ensure the fuel tanks are up to the job. The ship can fly if the tanks withstand 7 bar (7x atmospheric pressure) but the goal is to get them over 10 bar as that's what's required for future Human certification. 

Am I right in thinking of you could build a ship in space and launch it from a space station / moon base, it wouldn’t need to be able to withstand any atmospheric pressure?

but then how do space ships shield against little meteors and things? They must be hitting it like bullets all the time, but I imagine it has to be as light as possible, so doesn’t want to be covered in armour plating. 

[Carl Sagan]

4 hours ago, TigerTedd said:

Am I right in thinking of you could build a ship in space and launch it from a space station / moon base, it wouldn’t need to be able to withstand any atmospheric pressure?

but then how do space ships shield against little meteors and things? They must be hitting it like bullets all the time, but I imagine it has to be as light as possible, so doesn’t want to be covered in armour plating. 

The future is definitely "on-orbit manufacturing and assembly". What you need is the infrastructure to be able to use the raw materials available to us in space (so you're not carrying everything up from Earth's gravity well) and an automated industrial/manufacturing process. If Starship works it's big enough to be able to create this infrastructure, so in a way it might be the last big chemical rocket we need. 

Lightweight shielding is currently required because everything needs to be as light as possible when you're carrying it up from Earth, so the Whipple Bumper is the current mainstay, using layers of aluminium foil that are surprisingly effective at slowing down projectiles such as micrometeorites. There's a list of shielding techniques at https://hvit.jsc.nasa.gov/shield-development/

If you're building in space you don't necessarily have the same mass constraints if the final structure is to be stationary. But if you're moving it somewhere then the mass is still an important factor. So space stations would likely have more solid shielding whereas spaceships will be more lightweight to be able to whizz around.

In the future I hope for giant spaceships built in space that criss-cross the solar system but never land anywhere, and then we have smaller vehicles to ascend from and descend to planetary bodies. Earth is the most massive body we'll probably want to land and take off from. Starship is designed to take off on its own from Mars (single stage to orbit) for the trip home, but requires the giant Super Heavy booster to be able to reach orbit from Earth. Also Starship's Raptor engines are a brand new type that use methane and oxygen for fuel, on the premise that you can manufacture both fairly easily on Mars or anywhere in the solar system for that matter. 

[Carl Sagan]

The stand that was supporting the next prototype (SN9) collapsed yesterday, causing the Starship to fall into the wall of the chamber (the High Bay) where it was awaiting roll out onto the test pad. At the moment the cranes are there trying to sort things out, but it won't be ready for pressure/engine fires/flight tests quite so quickly. And we don't yet know if it's salvageable.

It's a shame as it was complete and ready to go, but even if it cannot be saved, there are another six (at least) under construction that will be ready soon.

[Carl Sagan]

The damage to the 9th prototype (SN9) when its stand failed doesn't appear terminal which in itself is a good thing and shows the resilience. The next road closures, when it is likely to be rolled out to the test pad to begin fuel tank pressure tests and also engine fires, are now scheduled for 28-30 December. 

Meanwhile, SN10 is racing to beat it, and it's not entirely clear which will make it out of the hangar first. There are now two test stands so we could even end up seeing two Starships on these together before the year I'd out! A little like in this render... 

[Carl Sagan]

The next prototype, SN9, has been rolled out to the test/launch site. It's only a small improvement from SN8, with the new rocket made completely of a new version of stainless steel that SpaceX thinks will perform better. I don't know if anything has been done to address the landing failure of SN8, due to a loss of pressure in the small fuel tank in the nosecone.

Meanwhile, here's a fantastic annotated recap of the launch and landing of SN8, the proof of concept that it's possible to use this method of flying and falling to land anywhere in the solar system without a runway. Including the Moon and Mars.

 

[cstand]

Been looking at the advantages of using graphene and came across this project that bodes well for the future.

https://www.graphene-info.com/orbex-secures-24-million-funding-its-graphene-enhanced-rocket

[TigerTedd]

4 hours ago, cstand said:

Been looking at the advantages of using graphene and came across this project that bodes well for the future.

https://www.graphene-info.com/orbex-secures-24-million-funding-its-graphene-enhanced-rocket

I need to know more about graphene and it’s practical applications. I feel like it could be my next obsession. 

I heard about it recently on a show Stephen Fry did that aired just after midnight on New Years about all the firsts since the turn of the millennium. It was really interesting and made me feel very old. But he got really excited when he started talking about graphene. 

I think I remember the guys who won a Nobel prize for it, then I’ve not really heard anything since. People seem to be very excited by it, but what could it actually mean for us in the future. Could it realistically be what everything is built from in a decade?

[Carl Sagan]

The Starship program is starting 2021 in good shape. While the 9th prototype (SN9) stands on the testpad, SN10 is fully built, while SN11 and SN12 only needs flaps adding. Work has progressed as far as SN17 while there's also significant progress on the first massive Super Heavy booster (this prototype is designated BN1, I suspect with B for booster).

Tonight a static fire test is planned for the three raptor engines on SN9. The rocket is held down while the engines briefly fire to check everything is in order.

Then the test flight to 40,000 feet is scheduled for Friday afternoon (UK time, 2pm-midnight), with a backup window on the Saturday with the same flight window. Bring it on!

Edited January 6, 2021 by Carl Sagan