Starship “EP2P” (Earth Point-to-Point) Discussion

[Nikxice]

I just watched Gwynne's recent TED talk posted by Grendal. I wished the interviewer had pressed her for more details on the BFR/BFS. I realize this presentation was probably given to a general audience and she's also obligated to protect proprietary information. There are still many of us hungry for more meat and potatoes. We can all relate to the Wow factor of flying to Shanghai and back home the same day to make dinner. I'd welcome more discussion of the challenges, especially those related to in-flight.

Some aspects of the BFS might make it easier to operate in Space and on other worlds vs. making those proposed 30 minute earth hops. The moon and Mars don't present the same weather factors we have here on earth. Air mass thunderstorms can easily develop in less than 30 minutes. As was previously pointed out, alternate landing sites plus required fuel reserves will be mandated by the FAA. There's no doubt that the BFS will have to be capable of a low altitude go-around. This scenario will also likely have to be successfully demonstrated in an engine out configuration. Not routine, but a training exercise practiced in aircraft sims everyday. From another era, I recall that the two stage Apollo LM had a brief few seconds in the landing phase that some referred to as a dead man's curve. It was an area where a combination of low altitude, sink rate, and a theoretical need to abort would have ended badly for the crew. Flight testing the BFS will make for some jaw dropping viewing. Regardless of new technologies, when it comes to ticketed passengers I don't see major waivers being granted for certifying BFS airworthiness that might compromise public safety.

I don't expect SpaceX to comment much on research concerning potential issues where they might still be seeking solutions. Just posing a few open questions with the hope that SpaceX eventually starts teasing us with more in-depth info.

 

[Brando]

Engineer Gwynne Shotwell was employee number seven at Elon Musk's pioneering aerospace company and is now its president. In conversation with TED curator Chris Anderson, she discusses SpaceX's race to put people into orbit and the organization's next big project, the BFR. The new giant rocket is designed to take humanity to Mars -- but it has another potential use: space travel for earthlings.

SpaceX's plan to fly you across the globe in 30 minutes

 

[Bobfitz1]

Duh. I knew that. Thanks for correcting me. I had originally thought I'd comment on the F9 then I switched to BFR but didn't change the fuel. Methalox will be cleaner than RP1. Does anyone know how much cleaner?

Pretty clean except for carbon dioxide. But at some point SpaceX might be able to produce it's methane with a process that pulls CO2 it needs from atmosphere.

"Burning methane releases only carbon dioxide and water. Since natural gas is mostly methane, the combustion of natural gas releases fewer byproducts than other fossil fuels. Because this is a chemical reaction, it is also possible to quantify the amount of water produced when methane is burned."

 

[ecarfan]

BFS. I realize this presentation was probably given to a general audience and she's also obligated to protect proprietary information. There are still many of us hungry for more meat and potatoes. We can all relate to the Wow factor of flying to Shanghai and back home the same day to make dinner. I'd welcome more discussion of the challenges, especially those related to in-flight.

Gwynne has a lot of self control in her public statements. Like you, I wish she would say more. But she’s not going to get into specifics for EP2P flights until they are close to selling tickets to the public. SpaceX will of course have to be specific with government regulatory agencies.

As was previously pointed out, alternate landing sites... will be mandated by the FAA.

Once the BFR is launched on a suborbital flight there wont’ be much latitude in changing course to an alternate landing site. It’s not an airplane.

There's no doubt that the BFS will have to be capable of a low altitude go-around.

If you could define what you mean by “low altitude go-around” that would be helpful. Again, a sub-orbital rocket trajectory doesn’t allow much latitude for altering course in flight.

In an airplane, a “low altitude go-around” could mean that when on final approach the tower tells you to “go around” and you apply power, pull up, and literally “go around” for another landing attempt.

You can’t do that with a rocket.

 

[landis]

Once the BFR is launched on a suborbital flight there wont’ be much latitude in changing course to an alternate landing

Not much longitude either. ;-)

 

[Nikxice]

Once the BFR is launched on a suborbital flight there wont’ be much latitude in changing course to an alternate landing site. It’s not an airplane.

Not sure why suitable alternates couldn't be established downrange or perhaps short of a regular BFS flight path. I'm assuming that the BFS could make adjustments and light up a couple of engines prior to reentry, so it seems feasible these sites could be located even hundreds of miles from the original destination.

You can’t do that with a rocket.

Sure you can go-around in a rocket......just maybe not quite yet. I have no idea if the BFS will be designed for this. Maybe someone here has the answer. I'm sure a bunch of SpaceX engineers know, but I've never heard it mentioned in a presentation or a Q&A. The ability to go-around in an aircraft is a pet peeve of mine. Having experienced a couple of hair raising runway incursions I value the extra margin of safety this procedure allows. Probably every airline and corporate pilot has done a sim ride with an engine out, down to wx minimums only to hear an instructor say, "there's an aircraft or a deer on the runway, go-around". You've got to wonder what the procedure will be when BFS is on approach and there's either an airspace violation or a sudden change in weather. It'll only take one event and the BFS will end up the same fate as the first passenger jet aircraft of last century, the de Havilland Comet.

The FAA will be extremely tough issuing a certificate to SpaceX for carrying revenue passengers. FAR Part 121 will likely add an appendix that might spell out, Powered Rocket Flight Requirements. No skirting these regs, even Air Cargo companies such as FedEx and UPS fly under 121. Also, probably plenty of scrutiny by the international body IATA, where safety is a top priority. Not trying to be a gloomy Gus, just realistic about the daunting challenges ahead. When it's ready, I'm all in for buying a ticket.

 

[mongo]

Go around is doable (just increase thrust), range for second landing is the question. The need for alternate landing sites is reduced since the entire trip is sub-hour, so conditions at the landing site will not change dramatically post launch. Contrast that to the 20 hour New York to Singapore route. Wildlife is also not as much of an issue due to the smaller landing area and negligible horizontal velocity.

 

[Electroman]

Thats what I thought, that there should be very little reasons why you may need to go around given that the whole trip is less than hour.

But there could be other issues such as: man made calamity, earth quake etc.. that happen at a moment notice without any warning.

Much of this is mitigated if BFR can land in land and you can have multiple landing zones all within the same general area. For instance Cape Canaveral can have easily 20 landing sites distributed across. And you can ferry them out in a high speed train to a central processing/immigration area.

 

[Bobfitz1]

I may be completely wrong but my hunch is that Shotwell's comments regarding SpaceX using one BFR to do 7 - 10 round trips in a day are meant to highlight future E2E rocket travel potential rather than a literal comment on SpaceX plans. Touting that hundreds of BFR flights per day around the globe doesn't hurt maintaining a helpful buzz about SpaceX after the huge Falcon Heavy PR win.

I'd further guess that their focus at this point is on building BFR to an unheard of standard of reliability and safety for a rocket.
Knowing a possibly lucrative wider use is at least a possibility one day, and a long shot (they sometimes happen) that it might grow over many years to be a big add'l revenue source.

 

[mongo]

Plus, they need to do something with all the BFR/BFS they build while waiting for the next Mars/Earth alignment.

 

[ecarfan]

I may be completely wrong but my hunch is that Shotwell's comments regarding SpaceX using one BFR to do 7 - 10 round trips in a day are meant to highlight future E2E rocket travel potential rather than a literal comment on SpaceX plans

In the interview she made a very clear and unambiguous statement that such flights would be a reality in less than a decade, just like she said that SpaceX would put a BFR with humans on Mars in less than a decade.

I take her at her word that those are goals that SpaceX is determined to achieve. And she was speaking in “Gwynne time” not “Elon time”.

I'd further guess that their focus at this point is on building BFR to an unheard of standard of reliability and safety for a rocket.

I agree that SpaceX will certainly try to achieve that. It is what is needed to make space exploration affordable and something that large numbers of people will adopt, whether flying a BFR from Los Angeles to Tokyo, or from Boca Chica to Mars.

 

[RDoc]

I'll be a lot more impressed when I hear about the FAA getting involved in the design at the beginning of getting an air worthiness certificate.

 

[PhantomX]

I'll be a lot more impressed when I hear about the FAA getting involved in the design at the beginning of getting an air worthiness certificate.

Agreed. Certifying a commercial airplane is hard and takes lots of resources and time, I can't imagine certifying a commercial passenger rocket transport system. And it's not just FAA, they'll have to get certification from EASA, JAA, CAA, and etc., since they'll be flying internationally. I would think flying to Mars will be easier than getting certifications to transport passengers.

 

[mongo]

If you already have a space/ NASA astronaut approved system, what additional requirement could the FAA add that would be difficult?

 

[N5329K]

Agreed. Certifying a commercial airplane is hard and takes lots of resources and time, I can't imagine certifying a commercial passenger rocket transport system. And it's not just FAA, they'll have to get certification from EASA, JAA, CAA, and etc., since they'll be flying internationally. I would think flying to Mars will be easier than getting certifications to transport passengers.

Flying to Mars will definitely be easier, quicker and cheaper to authorize than any dealings SpaceX will have getting certified to carry paying non-astronaut passengers on a terrestrial P2P rocket. And until rocket engines become orders of magnitude more reliable than they are now, I seriously doubt the technical, regulatory and financial viability of the entire scheme.
On a slightly more positive note, removing methane from the atmosphere, burning it, and releasing CO2 actually might not be as bad as it sounds, given that methane is many multiples worse of a greenhouse gas bad actor (it persists in the atmosphere far longer) than simple CO2.
Not counting collection, refrigeration, processing, storage and transport, of course.
Robin

 

[N5329K]

If you already have a space/ NASA astronaut approved system, what additional requirement could the FAA add that would be difficult?

Absolutely everything.
Robin

 

[Bobfitz1]

I agree that SpaceX will certainly try to achieve that. It is what is needed to make space exploration affordable and something that large numbers of people will adopt, whether flying a BFR from Los Angeles to Tokyo, or from Boca Chica to Mars.

Boca Chica to Mars sounds good. I'll have to get my seat reserved before they sell out! In flight movie likely to be the 'Martian'.

 

[mongo]

Flying to Mars will definitely be easier, quicker and cheaper to authorize than any dealings SpaceX will have getting certified to carry paying non-astronaut passengers on a terrestrial P2P rocket. And until rocket engines become orders of magnitude more reliable than they are now, I seriously doubt the technical, regulatory and financial viability of the entire scheme.
On a slightly more positive note, removing methane from the atmosphere, burning it, and releasing CO2 actually might not be as bad as it sounds, given that methane is many multiples worse of a greenhouse gas bad actor (it persists in the atmosphere far longer) than simple CO2.
Not counting collection, refrigeration, processing, storage and transport, of course.
Robin

Is there a process for methane extraction from the atmosphere? The Mars plan is H2O + CO2 -> O2 and CH4.

Absolutely everything.
Robin

Anything in particular?
Trans-oceanic planes are certified with only two engine. Single redundancy. Flammability for space system seems like it would be lower than domestic. Air quality systems are built in. Engine failure containment is already covered. Planes are already fly by wire. Are you thinking extra control actuator redundancy or manual landing leg actuation?

 

[SwTslaGrl]

I just saw an article where China is working on reusing rockets, modeled after SpaceX. Perhaps P2P will be accepted from US regulators, when other countries also are working on this?

Source: SpaceX customers' views on reuse

 

[Nikxice]

Absolutely everything.
Robin

I'll second those two words. Glad to hear a few voices of reason sound off.