Author Topic: What should be the payload for the demo flight of BFR/BFS?  (Read 7309 times)

Offline Ludus

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We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?
« Last Edit: 02/11/2018 02:09 am by Ludus »

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #1 on: 02/10/2018 06:16 pm »
We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?

A million tesla hot-wheel toys in tiny hundred gram ceramic reentry shells.

https://forum.nasaspaceflight.com/index.php?topic=44127.0 More seriously.
" Segmented Spin gravity habitat sized for launch in 2017 BFR Cargos"

Some sort of real stab at on-orbit assembly with wholly commercial grade parts with really stupid simple designs that are wholly inappropriate for space. (according to conventional wisdom).

Standard industrial arms and equipment, and see what breaks, and which of a dozen models from different manufacturers just works with no mods, and use that.

Get a whole pile of stuff from tech readiness level 'it might work' to 'flight tested'. Sure, 90% of the stuff has major problems, 50% catches fire.

That's just fine.
« Last Edit: 02/10/2018 06:23 pm by speedevil »

Offline archae86

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #2 on: 02/10/2018 06:36 pm »
I know an astronomer.  She knows how extraordinarily valuable the chance to put an experiment in orbit is to that community, and that very little of the community is in the NASA pipeline for flying anything, ever.

Given the value to their work, and their lack of access in normal conditions, these are people who could quite rationally accept the severe risk of schedule delay and considerable risk of mission failure which render the demo mission payload position unsuitable for most others.

I think the killer objection is how to get past the integration and safety assurance barriers without costing SpaceX an arm and a leg.  Maybe some educational institution could be engaged to handle most of the heavy lifting of those tasks, lured by the chance to "practice" on something real.

I am sure that well-informed people on this site can think of a thousand cogent objections.  So I'll pose the problem from the other side.  Can anyone here creatively propose a way such a project could be carried out without crippling cost and responsibility falling on SpaceX? 

I don't think it needs to be free.  The roadster stunt pretty clearly cost quite a bit.

Offline rakaydos

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #3 on: 02/10/2018 06:42 pm »
Also something to keep in mind... that first BFR is coming BACK. They need to test downmass capability as well as upmass.

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #4 on: 02/10/2018 06:44 pm »
I think the killer objection is how to get past the integration and safety assurance barriers without costing SpaceX an arm and a leg. 


No integration and safety assurance at all.
Quote
'you put it in this crate', we open the crate in orbit, and it springs out with this spring here.

The crates are designed to contain worst-case loads - loose pickaxes or anvils, for example.
Anything is fine, as long as it has no liquid propellant, and any batteries are charged to under 10% of their full charge.

Mass fraction of the crates is entirely unimportant.

If you have any stored energy other than batteries charged to 10%, you need to prove that your payload isn't going to leak or explode.
This may be comparatively quite expensive, especially for hypergols, for example.
An interesting option would of course be fuelling on orbit, from a spacex owned tank, once BFR is clear.


« Last Edit: 02/10/2018 06:48 pm by speedevil »

Offline Space OurSoul

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #5 on: 02/10/2018 07:14 pm »
We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?

A Tesla semi, of course
A complete OurSoul

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #6 on: 02/10/2018 07:16 pm »
With luck, it is almost an unimportant question.
Because the second launch is next week, and the fiftieth next month.

Offline ClayJar

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #7 on: 02/10/2018 07:19 pm »
Apparently BFS will start with short hops and gradually expand the envelope through its test program.  Do we think the BFR booster will have a similar hopping-first test program? If they both have retired a certain amount of risk through "Grasshopper-style" testing, the first full BFR/BFS demo flight might be more palatable for someone with a payload of greater value than Starman's Roadster.

Personally, I would think it would be an excellent opportunity for someone to put together a demo payload using off-the-shelf components and overbuilt design.  It could be an interesting example of what could be done when optimizing for cost with notably relaxed mass and size constraints.

Offline freddo411

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #8 on: 02/10/2018 07:39 pm »
I'll throw out two out of the box ideas:

1)  Orbit over 4 million matchbox-sized, cherry red telsa roadsters.  Bring them back and give them away to every 4th grader in the US ... with a video of a representative one in orbit.  That would 160 metric tons + packaging


2) A full sized replica of the Statue of Liberty.   I like this idea when it the BFR lands on the Moon or Mars.
« Last Edit: 02/10/2018 07:40 pm by freddo411 »

Offline Elmar Moelzer

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #9 on: 02/10/2018 09:06 pm »
For the moon landing demo, I would have a BFS outfit as a fully functional future moon base ready for 100 people (or maybe a few less if you want to increase comfort for the crew of the base).

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #10 on: 02/10/2018 09:29 pm »
For the moon landing demo, I would have a BFS outfit as a fully functional future moon base ready for 100 people (or maybe a few less if you want to increase comfort for the crew of the base).

Carrying on from the 'testing commercial equipment' concept.
http://www.mining.com/web/caterpillar-develops-proof-concept-battery-electric-lhd/


27 tons.

Will the tyres like lunar surface temperatures?
Doesn't matter hugely initially, as once you scrape off the top 30cm, you're at earth-normalish temperatures.
Will it last the lunar night - no - unless you put it inside a small tent.
Even if it doesn't, it can do a really interesting amount of work in one 'day'.
You will need to repaint it, and add MLI perhaps to some bits, as well as a radiator system, of course.

Offline TomH

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #11 on: 02/10/2018 09:47 pm »
Apparently BFS will start with short hops and gradually expand the envelope through its test program.  Do we think the BFR booster will have a similar hopping-first test program? If they both have retired a certain amount of risk through "Grasshopper-style" testing, ....

We also know that the BFS will land on legs and will not require as much precision in landing as the BFR booster. All the hopping with BFS may help refine the algorithms and hardware that will be employed in landing. As the BFR booster will have no legs and will land inside a cradle, it requires much greater precision. (Anyone want to comment on that-are we talking millimeters vs meters?) I would think that all the hopping and landing with BFS will help refine the software and hardware used on BFR and mitigate the risk of precision landing in the cradle. This would seem to be another reason that it makes sense to build BFS first and BFR second.

Online sanman

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #12 on: 02/10/2018 10:07 pm »
We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?

A Tesla semi, of course

Tesla semi is supposed to have a mass of ~15,000kg which wouldn't be that challenging for BFR.
Maybe you want a test mass that's a lot heavier than that.

I dunno - how about a cargo of seeds, which could be taken up to LEO and then brought back down. They could then be distributed across the globe for planting. Maybe the space radiation could cause some interesting mutations or something.

Offline chalz

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #13 on: 02/10/2018 11:01 pm »
We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?

A Tesla semi, of course

Tesla semi is supposed to have a mass of ~15,000kg which wouldn't be that challenging for BFR.
Maybe you want a test mass that's a lot heavier than that.

I dunno - how about a cargo of seeds, which could be taken up to LEO and then brought back down. They could then be distributed across the globe for planting. Maybe the space radiation could cause some interesting mutations or something.
The only way the Tesla Semi will happen is if its Elon's personal vehicle or someone else pays for it.

The seed idea is in the right direction, I think if Elon wants to motivate people to go to Mars with him he will have to get people emotionally. The frivolous stuff will be kept for the onboard entertainment system. Starman did this probably better than expected, people are inspired by it as well as entertained.

Having said that I thought they should half fill it with balls from a ball pit.  ::)

Offline ThePonjaX

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #14 on: 02/10/2018 11:46 pm »
Please, not again. We just pass the FH madness about their payload. I vote for close this thread  ;)

Offline Ludus

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #15 on: 02/11/2018 01:54 am »
As far as the up to 50 tons of downmass, that’s enough to give 1000 charities a chance to fly up to 100 lbs of stuff each. What sort of stuff? Basically commemorative/collectible merch. Coins, jewelry,stamps,etc. Stuff that can be donated and auctioned to raise money for the charities.

For example 10000 gold coins that weigh 1 Troy Oz, would weigh 311kg. They might sell for $1000 above their cost each and raise $10M. The demo might raise a couple hundred million for various charities from all over the world just using the downmass and still leaving room for 100 tons that stays in space.

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #16 on: 02/11/2018 08:49 am »
As far as the up to 50 tons of downmass, that’s enough to give 1000 charities a chance to fly up to 100 lbs of stuff each.

50 tons of downmass is from Mars.
It's 150 tons from LEO, nominal.

Offline First Mate Rummey

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Re: What should be the payload for the demo flight of BFR/BFS?
« Reply #17 on: 02/11/2018 11:16 am »
A Blue Origin New Shephard full of propellant + its capsule, about 35t... ;)

Offline cuddihy

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Re: What should be the payload for the demo flight of BFR/BFS?
« Reply #18 on: 02/11/2018 12:24 pm »
The only payload needed the first time around, and this is what I predict it will be, is plenty of propellant for landing. margin

Offline speedevil

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Re: What should be the payload for the demo flight of BFR/BFS?
« Reply #19 on: 02/11/2018 01:48 pm »
The only payload needed the first time around, and this is what I predict it will be, is plenty of propellant for landing. margin

If you're going actually orbital, with the BFR/BFS stack, 50 tons of cargo will end up with a lighter vehicle at landing than launching empty with a maximum fuel load, and it won't, more importantly, slosh.

BFS is planned to have been tested many times, SSTO, before full up BFR/S tests.

Online Galactic Penguin SST

Cradles and necessary equipment to bring the probably-end-of-life Hubble Space Telescope back to Earth.  ;)
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Offline speedevil

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Re: What should be the payload for the demo flight of BFR/BFS?
« Reply #21 on: 02/11/2018 03:22 pm »
Cradles and necessary equipment to bring the probably-end-of-life Hubble Space Telescope back to Earth.  ;)

Setting the stage for BEO test being Kepler?

Offline Lar

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #22 on: 02/11/2018 04:23 pm »
Please, not again. We just pass the FH madness about their payload. I vote for close this thread  ;)
(mod) A few points
- It's not a vote.
- You don't have to read the thread.
- The proper way to make suggestions about threads is via "report to mod" not by metadiscussion.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Ludus

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #23 on: 02/11/2018 06:00 pm »
As far as the up to 50 tons of downmass, that’s enough to give 1000 charities a chance to fly up to 100 lbs of stuff each.

50 tons of downmass is from Mars.
It's 150 tons from LEO, nominal.

It might be capable of something like that with several Tanker flights, IDK. I don’t think SpaceX has presented it as capable of it without added propellant,

Offline FutureMartian97

We’ve seen Elon’s Midnight Cherry red Roadster heading off toward the asteroid belt with Starman at the wheel. What’s an appropriate payload for the debut Orbital flight of the BFR/BFS?

A Tesla Semi

Offline speedevil

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Re: What should the payload for the demo flight of BFR/BFS?
« Reply #25 on: 02/11/2018 07:36 pm »
It might be capable of something like that with several Tanker flights, IDK. I don’t think SpaceX has presented it as capable of it without added propellant,

After IAC, where that slide was presented, changes happened.
Quote
Btw, we modified the BFS design since IAC to add a third medium area ratio Raptor engine partly for that reason (lose only 1/3 thrust in engine out) and allow landings with higher payload mass for the Earth to Earth transport function.
Elon
(reddit.)

SL raptors are baselined in there at 170 tons.
170 tons -85 - 50= 30 ton margin.
This is basically set by engine out performance.
Add another engine, and you can comfortably land 150 tons.
(from memory, there is a limit on Mars, which is under this, but this is for delta-v reasons)

Offline Zed_Noir

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Re: What should be the payload for the demo flight of BFR/BFS?
« Reply #26 on: 02/11/2018 10:28 pm »
Cradles and necessary equipment to bring the probably-end-of-life Hubble Space Telescope back to Earth.  ;)

Setting the stage for BEO test being Kepler?

We know there is a collector of antique space hardware out there name Bezos. Wonder if he will spring for a showroom with Hubble  and Kepler in display after fetching them back to Earth.  :)

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