SpaceX vs. Everyone - ULA, NG, Boeing, Lockheed, etc.

[JB47394]

I also expect that within 4 years SLS will be cancelled and Starship will be employed, as by then the obvious massive cost savings will be an irresistible lure given the very high cost of lunar base infrastructure.

SLS plus Orion is the only vehicle combination that can get astronauts to the Moon right now.

The Chinese are planning to go to the Moon with their Long March 10 rocket, which can get 27 tons to Trans Lunar Injection (TLI). They're going to use two flights to get the crewed spacecraft and lunar lander to the Moon separately, where they'd rendezvous. Much like Artemis.

If SLS is cancelled, then Orion is dead in the water. Something would have to be adapted.

Perhaps the simplest hybrid of Starship and Orion is to launch an uncrewed Orion stack in Starship. Launch the crew in Dragon. Deploy Orion from Starship, and then the crew transfers over. A new kick stage would be added to the Orion stack to get to Moon orbit. Then you have the separate mission of launching HLS Starship, refueling on orbit, and going to the Moon to take the crew to the surface and back. Return in Orion per Artemis plans.

Note that the kick stage for Orion could be arbitrarily large. The Orion stack is 26.5 tons, leaving over 100 tons for the kick stage.

If you're thinking that Starship would be human rated in four years, then we're still stuck. I believe Starship would need to be tanked at the Moon. The great appeal of Orion is that relatively little mass has to be moved around on the return trip. Until we have a propellant depot at a given destination, return trips with Starship are impractical.

 

[ecarfan]

If you're thinking that Starship would be human rated in four years, then we're still stuck. I believe Starship would need to be tanked at the Moon.

How about this: two Starships launch, one is a stretched V3 Starship HLS, the other is just to go to and from LEO with crew so not a stretched V3 (or could be), the HLS ship refuels in LEO, they dock so crew can transfer to the HLS which then goes to the lunar surface, stays for awhile and then returns to LEO, crew again transfers and returns to Earth.

 

[JB47394]

How about this: two Starships launch, one is a stretched V3 Starship HLS, the other is just to go to and from LEO with crew so not a stretched V3 (or could be), the HLS ship refuels in LEO, they dock so crew can transfer to the HLS which then goes to the lunar surface, stays for awhile and then returns to LEO, crew again transfers and returns to Earth.

Let's say that a V3 Starship has a dry mass of 120 tons, with a propellant load of double that of V2, or 2400 tons. Assume that HLS adds 150 tons of dry mass for seats, walls, consumables, instruments, space suits, etc. So that's 270 tons total of roundtrip mass. Let's add 30 tons of propellant as a reserve for a nice round 300 tons of round trip mass.

That gives us 7,782 m/s of delta-V. The round trip from LEO to the Moon's surface and back needs 11,320 m/s (each leg is 5,660 m/s).

To build a single vehicle capable of making the round trip from LEO would require a propellant load of about 7000 tons.

Now, if the engines could improve their exhaust velocity (Isp) by 50%, then the V3 Starship with 2400 tons of propellant could make it. Delta-V scales linearly with exhaust velocity, but only by the natural log with propellant mass.

This is why they want to use Orion for the return trip. Its low mass relative to Starship and its ability to directly reenter the Earth's atmosphere mean that its delta-V requirements are more easily achieved and lower.

This is why I want a propellant depot at the Moon. Even a V2 Starship has enough delta-V (5,854 m/s) for a one-way trip (5,660 m/s).

 

[mongo]

Let's say that a V3 Starship has a dry mass of 120 tons, with a propellant load of double that of V2, or 2400 tons. Assume that HLS adds 150 tons of dry mass for seats, walls, consumables, instruments, space suits, etc. So that's 270 tons total of roundtrip mass

That's a lot of interior...
Orion is under 10 tons.
A 787-800 is 75 tons.
Shuttle was 120 tons launch mass.

 

[JB47394]

That's a lot of interior...

And life support, consumables, science instruments, experiments, rovers, elevator, and whatever industrial equipment that's supposed to lead to a Moon colony, science station or whatever. Plus backups. The point of building Starship is to have the mass budget so that we're not always crammed into little capsules with bespoke hardware that allows us to perform a touch and go on the Moon.

It doesn't really matter one way or another because we're not getting a round trip in a Starship, V3 or not. Go with an empty cargo bay and run the tanks dry and a 100 ton V2 gets us 9,131 m/s, while a 120 ton V3 gets us 10,838 m/s. If SpaceX somehow manages to get a V3 down to a svelte 100 tons of structure and engines for the trip, then it could make it and even carry along 4 tons total of cargo and propellant reserve.

All these numbers are most impacted by the exhaust velocity of the Raptor Vacuum. I'm using 3,560 m/s, but I don't know if that's accurate. Ten percent higher or lower means ten percent more or less cargo & reserve.

 

[scaesare]

I'm sure that's true to a great degree... the US wasn't exactly a hotbed of innovation either. But the general feel I get is that is that the "dominant position" was back in the USSR days, and since it's dissolution, a lot of that infrastructure and technology has languished... the Burans at the Baikonur Cosmodrome come to mind... along with old warehouse stores of engines found, dusted off, and sold.

Just looked it up and there's RD-19X engines that have been designed/built in the last 10-15 years, so there's that. And quite frankly your point about everyone else is probably spot on... NASA and it's traditional suppliers don't have an abundance new to show for the last decade....

We were recently discussing Russia, and this quote was in the Ars Weekly Roundup:

The only new, large rocket Russia has developed in nearly 40 years, the expendable Angara A5, is still launching dummy payloads on test flights a decade after its debut.

So yeah, Russia has some catching up to do if they want to be "dominant"...

 

[JB47394]

You've got your point-to-point delivery via Starship and you've got this thing. Aviation week says

Sierra’s vision is for the Ghost is to remain in standby mode on-orbit for up to five years with each spacecraft outfitted with pre-determined supplies such as a survival kit, an inflatable boat, rations and weaponry. Once activated the system is designed to re-orient the decelerator heat shield for re-entry while a deorbit motor slows the spacecraft to 7,000 m/sec. (22,966 ft./sec.).

 

[TunaBug]

You've got your point-to-point delivery via Starship and you've got this thing. Aviation week says

I first thought that was one of the stupidest ideas ever. "I wonder how much spaghetti mankind has wasted trying to find things that stick to a wall?". But then the guy mentioned the military aspect of being able to have supplies instantly dropped to somebody, reminding me of the supplies that a sponsor could gift to a tribute in the Hunger Games. Maybe a neat idea? The demos were

 

[JB47394]

I just found out that Lockheed Martin got a DARPA contract in September 2023 to build and fly a nuclear thermal propulsion (NTP) demonstrator no later than 2027. NASA is also involved.

Lockheed Martin Selected to Develop Nuclear-Powered Spacecraft

DARPA and NASA's Joint DRACO Project Technology Will Help Enable Humans to Travel to Mars DENVER, July 26, 2023 /PRNewswire/ -- Lockheed Martin [NYSE: LMT] has won a contract from the Defense...

news.lockheedmartin.com

 

[ecarfan]

Thanks for posting that link. From the press release:

Chemical propulsion engines have long been the standard for spaceflight, but for humans to travel to Mars, they will need much more powerful and efficient propulsion.

Well…I don’t think that statement is entirely accurate. Starship will be able to reach Mars using chemical propulsion, but will need to be refueled on Mars to return to Earth.

NTP system uses a nuclear reactor to quickly heat hydrogen propellant to very high temperatures and then funnels that gas through the engine nozzle to create powerful thrust. The fission-based reactor will use a special high-assay low-enriched uranium, or HALEU, to convert the cryogenic hydrogen into an extremely hot pressurized gas. The reactor will not be turned on until the spacecraft has reached a nuclear safe orbit, making the NTP system very safe.

So the nuclear reactor is boosted to orbit with a conventional first stage and second stage and then it is activated. Is the reactor in the second stage or in a third stage. What rocket is capable of delivering that kind of payload to LEO?

 

[JB47394]

Well…I don’t think that statement is entirely accurate.

It's a Lockheed Martin press release, so it's a Lockheed Martin-centric view of the universe.

If they can build an NTP rocket with twice the exhaust velocity of a Starship, they're going to have something very nice. It'll be the go-to for running around the solar system. It has the nice side-effect of (potentially) being a multi-fuel rocket. Hydrogen, ammonia, water, methane, whatever. Hydrogen and methane would require cryogenic storage, but water and ammonia can be kept liquid at some convenient temperatures.

That said, would they ever pursue economies of scale to allow more aggressive space exploration?

What rocket is capable of delivering that kind of payload to LEO?

I assume even a Falcon 9 could do the job, but they'll want a Vulcan flight. It shouldn't be much on weight. It won't be shielded (except to ensure that if the launch fails, the fissile material won't be scattered). It won't generate electricity. It won't run for more than a day or two. And so on. At its foundation, it's just fissile material heating the propellant and sending it out through a nozzle. Obviously there's a lot more to it in terms of how those three are brought together to produce that effect, but calling it a reactor is fairly academic. They may create something absolutely tiny in an effort to keep down the amount of fissile material. "Green" types are going to go ballistic when they hear about this thing.

I wonder what they'll do with it when the test is concluded.

 

[Cosmacelf]

Frankly, I would like to see SpaceX get into the nuclear propulsion game. I do wonder why they haven't tried to yet.

 

[nativewolf]

Like all great exploration, we stand on the shoulders of past efforts. Let NASA do what it should do best, pay for research projects like this, and then if it appears useful...then apply spacex, rocketlabs, etc to the problem of scale.

 

[JB47394]

Frankly, I would like to see SpaceX get into the nuclear propulsion game. I do wonder why they haven't tried to yet.

I think it's because SpaceX must do chemical rockets first (NTP cannot get to orbit), and that NTP development is not synergistic with that effort. The technologies, regulatory hurdles, personnel and mindset would be completely different. You can't Move Fast and Break Things with fissile material involved. So NTP is just not Elon's style. It's much better suited to the Slow and Steady of traditional aerospace working off a government contract.

The sad thing is that it may well be another such effort that comes to nothing. Will they figure out how to make them in high volume and low cost? I seriously doubt it. They'll want to build them for a billion each, and design them so that they're best used on one-way missions (so they're disposable and the customers need to buy a new one for each mission). Worse, the key technologies may get patent protection despite the work being part of a government contract. As I recall, Lockheed Martin is putting some of their own money into the project, perhaps so that they can own the patents.

However, if LM creates an NTP engine that hits the theoretical number of 10,000 m/s exhaust velocity, then we've just become a space faring civilization. That's bonkers levels of delta-V. Assume a Starship-class vehicle with 100 tons of structure mass (engines, shielding, structure, tanks, plumbing), 1200 tons of propellant, and 200 tons of cargo. Now you have 16,000 m/s of delta-V. You can roundtrip to a low orbit of any of the inner planets. Go to Mars and back on one load of propellant. It's a great shuttle.

 

[nativewolf]

So the upside here is that we are discussing whether or not LM can hit on a design with a 10000m/s exhaust velocity. Not that it is science fiction. But such reality is tantalizingly possible. If NASA is contemplating so will Japan, China, India, Europe.

 

[JB47394]

If NASA is contemplating so will Japan, China, India, Europe.

I would think that the China question is the most important. They're very serious about their space program, and their regulatory environment is whatever they need it to be. Given China's prowess in industrial espionage, as soon as Lockheed Martin's project is showing signs of promise, the Chinese will probably jump all over the technology.

 

[nativewolf]

I expect so but then Japan will be too and Europe as well and Europe has some top notch Nuke engineering folks. Exploration always moved along faster with a bit of pressure.

 

[ggr]

One thing that needs to be considered is your speed vs. that of exhaust. Once you reach the speed of exhaust, it does not help you very much.
You need the speed of exhaust as fast as possible.
Ultimately, you want to use ion engine or photons to propel your rocket to go very far.

This is a common fallacy. The thrust doesn't change just because of the speed of the rocket.

 

[scaesare]

We were recently discussing Russia, and this quote was in the Ars Weekly Roundup:



So yeah, Russia has some catching up to do if they want to be "dominant"...

And they are gonna wipe the floor with SX when it comes to reusability:

Russian space chief says new rocket will put Falcon 9 reuse to shame

There's just one catch...

arstechnica.com

 

[Cosmacelf]

What the hell has this thread been taken over with???

Getting back on topic, or at least closer to topic, I'm sure you'll all be surprised that the California Coastal Commission has issues with SpaceX's proposed increased number of launches from Vandenburg.

Coastal Commission waits to decide whether SpaceX rocket launches can increase

The California Coastal Commission recently delayed deciding on whether SpaceX should be able to increase the number of rockets it launches from Vandenberg Space Force...

www.santamariasun.com