Tom Mueller interview 02 May 2017

[Space Ghost 1962]

(The first hard drive I ever maintained was 14MB and the size of a dishwasher) Used on a system with core memory)

Good old Memorex 660...

Back in 1976 the hard drive on the computer in the Pychoacoustic Lab at SUNY Binghamton was either 5 or 10 MB.  Not really the good old days.

Likely an DEC PDP-11 RK-05 "pizza platter". Often had "head crashes".

add:

I bought my first disk drive for a start-up company I was doing. It was an ATASI 40MB 5.25" hard drive with a ST-506 interface to a Western Digital  WD-1002 controller. About $5,000.

[Kenp51d]

(The first hard drive I ever maintained was 14MB and the size of a dishwasher) Used on a system with core memory)

Good old Memorex 660...

Back in 1976 the hard drive on the computer in the Pychoacoustic Lab at SUNY Binghamton was either 5 or 10 MB.  Not really the good old days.

Likely an DEC PDP-11 RK-05 "pizza platter". Often had "head crashes".

add:

I bought my first disk drive for a start-up company I was doing. It was an ATASI 40MB 5.25" hard drive with a ST-506 interface to a Western Digital  WD-1002 controller. About $5,000.

Now y'all are bringing some old memories, (does that mean I'm old?).
Mini's I think they were ( we referred to them main frames). 16 k of core memory. Had 3 of them, and an extended memory unit with a wopping 16k of core also.
Hard drive? What the heck was that? We used paper tape.
This was on my second ship, nuke guided missile cruiser.

Ken

Sent from my XT1565 using Tapatalk

[QuantumG]

Yeah, the idea that you could build a gas generator cycle rocket for less than $10M was once unbelievable. Any day now someone will produce one in their garage, although electric pumps have essentially taken that scale in a different direction.

I once saw a comment that rl10 (not a GG, of course), could be built for about the same as a helicopter engine ($40k?) after a lot of re-engineering.

By "build" I meant development. As in, hey, let's start a rocket company, got an engine? Nope. Let's make our own! $10M later, oh well, guess we'll close up shop.

[AncientU]

Wonder how many of these development decisions TM discusses like face-shutoff and their associated challenges/costs are included in the $1B investment in reusable rockets SpaceX now advertises.  Could be most everything past Falcon 9 v1.0 with M1-Cs.  Lots of benefits have accrued to the company before considering reusability, so they could be 'double-booking' these development costs.

$1B always seemed high to me...

[Lars-J]

Wonder how many of these development decisions TM discusses like face-shutoff and their associated challenges/costs are included in the $1B investment in reusable rockets SpaceX now advertises.  Could be most everything past Falcon 9 v1.0 with M1-Cs.  Lots of benefits have accrued to the company before considering reusability, so they could be 'double-booking' these development costs.

$1B always seemed high to me...

I would bet it is included. Any kind of reusability with propulsive landing scheme is extremely reliant on a reliable engine that *will* start... And to my knowledge, the M1D has never failed a restart in flight. (The M1DVac did once, but has since operated flawlessly as far as we know)

[AncientU]

Wonder how many of these development decisions TM discusses like face-shutoff and their associated challenges/costs are included in the $1B investment in reusable rockets SpaceX now advertises.  Could be most everything past Falcon 9 v1.0 with M1-Cs.  Lots of benefits have accrued to the company before considering reusability, so they could be 'double-booking' these development costs.

$1B always seemed high to me...

I would bet it is included. Any kind of reusability with propulsive landing scheme is extremely reliant on a reliable engine that *will* start... And to my knowledge, the M1D has never failed a restart in flight. (The M1DVac did once, but has since operated flawlessly as far as we know)

Practically anything that decreased mass, increased thrust, plus the obvious like grasshopper, landing legs, grid fins, etc. could be heaped together.  Could even reason, somehow, that the octaweb was a contributor to reusability -- maybe a stretch too far.

[deruch]

Wonder how many of these development decisions TM discusses like face-shutoff and their associated challenges/costs are included in the $1B investment in reusable rockets SpaceX now advertises.  Could be most everything past Falcon 9 v1.0 with M1-Cs.  Lots of benefits have accrued to the company before considering reusability, so they could be 'double-booking' these development costs.

$1B always seemed high to me...

I would argue that it includes plenty of things long before that as well:

The insistence on reusability “drives the engineers insane,” says Vozoff. “We could’ve had Falcon 1 in orbit two years earlier than we did if Elon had just given up on first stage reusability. The qualification for the Merlin engine was far outside of what was necessary, unless you plan to recover it and reuse it. And so the engineers are frustrated because this isn’t the quickest means to the end. But Elon has this bigger picture in mind. And he forces them to do what’s hard. And I admire that about him.”

http://www.airspacemag.com/space/is-spacex-changing-the-rocket-equation-132285884/?all

[ehb]

Finally got around to try to listen to the interview.
Original link appears dead, fortunately found it on youtube

[QuantumG]

48 minute mark: "We want to exploration first before we do colonization."

[guckyfan]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

[Lars-J]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

There's going to be more exploration than that. The first few ITS landings will be for small exploration outposts at first... They are not going to start colonization with the first flights.

[guckyfan]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

There's going to be more exploration than that. The first few ITS landings will be for small exploration outposts at first... They are not going to start colonization with the first flights.

In my understanding they do. It will be a permanent base with the clear intention to expand it into a settlement. Sure they will look into the surrounding area. Probably supported by NASA who will send their scientist astronauts.

[QuantumG]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

If ya actually listen to the recording you'll know he wasn't talking about that.

[Lars-J]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

There's going to be more exploration than that. The first few ITS landings will be for small exploration outposts at first... They are not going to start colonization with the first flights.

In my understanding they do. It will be a permanent base with the clear intention to expand it into a settlement. Sure they will look into the surrounding area. Probably supported by NASA who will send their scientist astronauts.

Then we are arguing semantics about what 'colonization' means. An exploration outpost is not a colony in my mind, but I realize that there will be a fuzzy transition period if that outpost eventually becomes a starting point for a colonization effort.

[LouScheffer]

In the interview, Tom Mueller said:

by going face-shutoff, we got rid of the main valves

Makes sense, but then why does the launch sequence still talk about pre-chilling the engines?  If there are no main values, then I'd think that as soon as they loaded the tank, the fuel/LOX would flow down through the engine until it encountered the shutoff at the injector face.  So the engine would already be chilled, just sitting there.

Perhaps they are pre-chilling the gas generator, which *is* on the other side of some valves?  Perhaps there is another valve (but not a "main" valve) in the way?  Anyone have any idea?

[cscott]

In the interview, Tom Mueller said:

by going face-shutoff, we got rid of the main valves

Makes sense, but then why does the launch sequence still talk about pre-chilling the engines?  If there are no main values, then I'd think that as soon as they loaded the tank, the fuel/LOX would flow down through the engine until it encountered the shutoff at the injector face.  So the engine would already be chilled, just sitting there.

Perhaps they are pre-chilling the gas generator, which *is* on the other side of some valves?  Perhaps there is another valve (but not a "main" valve) in the way?  Anyone have any idea?

I bet they don't want any of their LOX boiling into gas as it "just sits there" in the lines.

[intrepidpursuit]

In the interview, Tom Mueller said:

by going face-shutoff, we got rid of the main valves

Makes sense, but then why does the launch sequence still talk about pre-chilling the engines?  If there are no main values, then I'd think that as soon as they loaded the tank, the fuel/LOX would flow down through the engine until it encountered the shutoff at the injector face.  So the engine would already be chilled, just sitting there.

Perhaps they are pre-chilling the gas generator, which *is* on the other side of some valves?  Perhaps there is another valve (but not a "main" valve) in the way?  Anyone have any idea?

There have to be valves on the inlets to the turbine or they'd never be able to shut off or throttle the engine. LOX sitting in the engine doesn't necessarily cool the turbine and the turbopumps.

[ArbitraryConstant]

First constellation table in image.

LEO & VLEO technical PDF's attached.

Hm... Edmonton is 53.5 N, which is the northernmost major city in NA.

[IainMcClatchie]

First constellation table in image.

LEO & VLEO technical PDF's attached.

Hm... Edmonton is 53.5 N, which is the northernmost major city in NA.

The ground stations can be a few degrees north of the orbital inclination.  Here's the coverage graph for a 53 degree inclination satellite constellation.  (I've posted this before, but I thought it was pertinent.)

[meekGee]

48 minute mark: "We want to exploration first before we do colonization."

Sure, that are the RedDragon missions.

There's going to be more exploration than that. The first few ITS landings will be for small exploration outposts at first... They are not going to start colonization with the first flights.

In my understanding they do. It will be a permanent base with the clear intention to expand it into a settlement. Sure they will look into the surrounding area. Probably supported by NASA who will send their scientist astronauts.

Then we are arguing semantics about what 'colonization' means. An exploration outpost is not a colony in my mind, but I realize that there will be a fuzzy transition period if that outpost eventually becomes a starting point for a colonization effort.

I think the secret is that if you size your transport system for colonization, you can afford to do exploration by brute-force, the same way you can do a "boots first" colonization instead of "robotic ISRU first".

Land a LOT of mass, but send only a 10-person crew - they can spend 2 years surveying several sites, while even more supplies are landed.  Then another 40 people come in, and they start building at the best spot.