In the near future we may be witness to an advancement in the use of materials that harken back to the earlier days of the US space program. And a rocket constructed of one of the early materials, stainless steel, that will be powered by methane, aka “swamp gas”.
SpaceX, after planning to use composite fuel tanks and aluminum alloy rocket bodies suddenly dropped that after considerable expenditure in the manufacturing processes needed and designed and started production of a prototype “Star Hopper” sub-orbital vehicle, primarily from stainless steel. They are doing this an open part of their Boca Chica, Texas facility. The narrator makes a great comment, calling the finned, short and stout shape of this vehicle as looking like “an H.G. Wells fever dream of the future”. It looks nearly Art Deco to me.
A controversial part of this design is the planned use of cooling pores in the outer skin of one side of the ship, to serve as a “heat shield” by expelling methane to dissipate the heat of re-entry. As the full up Starship model is intended to go to Mars, do an atmosphere entry there and then come back to Earth and do a re-entry here, an ablative type of heat shield will not serve.
Methane is the fuel of choice for both Blue Origin's new BE-4 and SpaceX's Raptor rocket engines. The complexity of why this is a good selection takes a good bit of an excellent video I have watched three times to try to absorb all the basic facts. Neither engine has flown yet but the commitment is there to make each a reality, as they are both far along in development and testing for flight.
The BE-4 will power Blue Origin's New Glenn heavy launch system and United Launch Alliance’s Vulcan rocket. The Raptor will power the SpaceX Star Hopper sub-orbital development vehicle and the ambitious Starship heavy launch system they intend to use for orbital cargo, missions to the Moon and also Mars.
Of note, methane can be produced on Mars, if needed, to fuel a return journey to Earth. No one said this was going to be cheap or easy! Hydrogen can be produced as well. Both will require water ice to be mined.
I am going to link in two YouTube videos that address both subjects, one relatively short and one nearly 50 minutes long. They both do a superb job of explaining each subject for we non-engineering types. The longer video, from Everyday Astronaut, has time stamps to go to individual segments. Disclosure, Everyday is a SpaceX fan.
https://en.m.wikipedia.org/wiki/Raptor_(rocket_engine_family)
what a gorgeous design concept. The nostalgic look will probably fuel funding. The Shuttle always left me cold...clunky and uninspired. On the other hand, my son and son-in-law loved the shuttle (now in their late twenties, early thirties).
Posted by: DH | 22 June 2019 at 04:06 PM
Very retro looking. Makes me think of von Braun's V-2.
They did a tethered lift-off of one meter back in April. When is the next one scheduled? And how high a test flight would you think?
Can't find anything on thrust-to-weight ratio on Raptor.
Posted by: Eugene Owens | 22 June 2019 at 07:14 PM
Should be pretty soon on the untethered test. If it goes well, they are aiming at 16,000 feet.
From Teslerati.
"Longer tests demand that SpaceX begins expanding the known performance envelope of its full-scale Raptor engine. Towards that end, longer-duration tests would need to be done at the company’s McGregor, TX development facilities to reduce risk, tests that Musk confirmed are already well underway. A recent Raptor static fire reportedly lasted no less than 40 seconds, more than enough time for a single-engine Starhopper to significantly expand both the maximum altitude and velocity of future hop tests. In support of the upcoming Starhopper test campaign, significant construction work is also ongoing at SpaceX’s Boca Chica test and development facilities."
In the YouTube video by Everyday Astronaut, he has a table with the thrust to weight ratios of a series of engines and other stats, including specific impulse.
Posted by: BabelFish | 22 June 2019 at 07:39 PM
Thanx. And thanx for pointing me to that Teslarati website. Not that I could ever afford a Tesla, but I can dream about the Truckla conversion they mentioned.
Posted by: Eugene Owens | 22 June 2019 at 09:32 PM
OK, lets get down to business. For me a day without the car is a luxury and a week nirvana. So in my ideal world it's sitting around doing nothing for most of the time. Quietly trickle charging from solar and when that's not doing too well refuelling off a little wind turbine. Nothing fancy, you understand, the wind turbine, just dirty power coming straight off a crude dynamo and no rectifiers or such like needed.
I'm not suggesting you should hang the methane digester off the back but for those long windless winter days hybrid's the way to go so it'll have to be around somewhere nearby.
Regenerative braking, goes without saying. Lots of hills round my way. Don't worry too much about top speed. If I feel the need for boy racer stuff a motorbike on the same terms'll do fine.
Those are the specs. Can you do it without the lithium? Mucky stuff and costs too much. Get your boy Elon onto it. He'll turn it out in an afternoon and when he's done we can start thinking about the tractor.
Posted by: English Outsider | 23 June 2019 at 08:23 AM
Wow! What fun!
Posted by: Linda | 23 June 2019 at 10:30 AM
BabelFish -
I finally sat through the longer EverydayAstronaut vid. It was well worth it. I liked his neat metaphors especially the one on Goldilocks. I'll be checking out his other YouTube videos.
Posted by: Eugene Owens | 23 June 2019 at 12:28 PM
EO -
I think John Deere already has an electric tractor. Probably they got the idea from Elon.
I just want an electric or hybrid pickup truck with enough beef under the hood to be able to tow my boat trailer down to the launch ramp. Or 'up' if the fish are biting in the mountain lakes.
Posted by: Eugene Owens | 23 June 2019 at 12:32 PM
Babelfish, I've only watched the short video so far and I'm thrilled at what I learned about materials science. Thanks for the education. Now that you are our designated space correspondent, I hope you'll soon do a posting on solar sails. Those babies have done more to excite my interest in space exploration as much as the first Moon landing and my first son's youthful desire to be a space shuttle pilot. I remember some early space art showing solar sails. It fueled my romantic notions of deep space exploration.
Posted by: The Twisted Genius | 23 June 2019 at 01:23 PM
Thank you, TTG. That would be a good subject indeed. Will try to oblige this coming week.
Posted by: BabelFish | 23 June 2019 at 02:26 PM
Bill Nye's experimental LightSail2 is supposed to launch tonight on Falcon Heavy. Or at least the suitcase it is launched in goes up tonight. It will be about a week before the sail pops out of the box and unfurls. It is not intended as interplanetary, just a proof of concept for orbiting solar-sailing-mini-satellites.
http://www.planetary.org/explore/projects/lightsail-solar-sailing/
Posted by: Eugene Owens | 24 June 2019 at 03:52 PM
Yes. If I am awake at 11:30 PM tonight (a big if), I should be able to see the lift off to the South.
Posted by: BabelFish | 24 June 2019 at 04:20 PM
I am unsure why Musk gets so much disdain in some circles. Yes, he sounds like a piece of work personally, but a from-the-ground-up car company, a space payload delivery company, and a supposedly game-changing power storage system for residential use (or so I've heard from people who design residential renewable systems). Isn't that all pretty impressive?
I'm not a spook so I don't understand whether he is just a Zuckerberg, who I gather is more of a psyop figurehead for the NSA et. al., privatization of censorship, elite narrative control, and surveillance? Maybe he's just a front for spinning tax-payer funded black budget products out into the consumer world for fun and profit?
Posted by: O'Shawnessey | 25 June 2019 at 11:59 AM
I'm buying cows.
One thing I wanted since being about five years old was to get into space.
The cows and I are going to make it.
Posted by: PRC90 | 26 June 2019 at 11:51 AM
Fendt also do electric tractors now, complete if required with on farm power generation from renewable sources. I bet the power generation works, too - there's a small farmer in Germany who supplies an entire village from his methane digester. The capital cost must have been exorbitant but that's one village sorted out. The most recent John Deere tractors use a cable feed. More fun than use round my way, a cable feed, with trees dotted around all over the place.
But I was unable to give the subject my full attention. Too busy being consumed with envy of the fishing grounds at your disposal.
Posted by: English Outsider | 26 June 2019 at 04:30 PM
EO -
Deere has both a battery tractor and the cabled version you mention. No trees in soybean or corn fields that I know of, and lots more power than the battery model, plus it is autonomous. But it seems a bit hokey or Rube Goldberg to me.
Posted by: Eugene Owens | 27 June 2019 at 12:24 AM
Hi BabelFish,
Thanks for this article.
Posted by: Sawyer | 23 September 2019 at 02:59 PM
Hi BabelFish,
Thanks for this article.
Posted by: Sawyer | 23 September 2019 at 02:59 PM