My piece on yesterday’s announcement is up at Popular Mechanics.
11 thoughts on “The Tech Behind The Falcon Heavy”
The second stage makes orbit. The hopefully-reusable boosters are dropped ASAP.
How close does the -first- stage, the central F9, make it to orbit? Or, at least, what’s its velocity at separation? Or, perhaps, launched with a minimal/non-existant “second stage”? It’s completely full of fuel at booster-burn out.
If the upper stage isn’t added at launch, or is simply an aerodynamic-improvement of no major weight, is it possible that the central core could be making orbit? How much extra fuel would be needed if the ‘second stage’ were re-added as yet-another ‘extended range tank’? With 9x re-ignitable engines, the tanks, and the designed-in ability to refuel (under thrust, admittedly), it’s already a start on a very large EDS -or- a depot.
After three missions, attach the three cores into the FH ground configuration.
What kind of technical risk is the cross feed of fuel from the boosters to the central motors? I’m assuming there is still some fairly serious engineering to work out with regards to the pump, valves and fuel lines so that it all works smoothly during staging. Or, is switching fuel sources in flight pretty much a known quantity in rocket design?
There is no switching of fuel sources. Presumably the pumps have two outlet lines — one to the engines and the other to the center core. If everything is running smoothly the back pressure from the continually full center will ensure that the power heads get the inlet pressure they need in the side cores. When the sides are empty, the engines shut down and they separate, including the umbilical (just like the ET from the Orbiter).
Cross feed isn’t a new idea — we were looking at it in the eighties at Rockwell (and I’m sure a lot were doing so earlier as well), but this will be the first actual implementation of it that I’m aware of.
I’m thinking that the improved Merlin engine is going to find its way to the Falcon 9, and a Falcon 9 stretched in in the cards with 40% improved payload over the original.
IANAE, but this crossfeed looks like something else that could go wrong under stress.
How far away are we from a test launch?
Did Elon use the 95,000 lb thrust figure for the Merlin 1C in the press conference yesterday? I’ve seen that reported a few places, but SpaceX’s site says it’s 125,000 lbs.
95k is the figure for the current engine, 125k is their previous estimate for the upgraded engine
“I’m thinking that the improved Merlin engine is going to find its way to the Falcon 9, and a Falcon 9 stretched in in the cards with 40% improved payload over the original.”
I heard the Falcon 9 Improved was now rated to 16 tons to low orbit.
Assuming the now longer Falcon 9 can handle the bending and flexing cause by having a spaceplane on top, it should be able to boost Dream Chaser now.
Mass for the DC is 9000kg. The upgraded F-9 should be able to handle it in spades assuming the above stipulations can be met. Even give a bit of margin for mass growth and engine out too.
Yesterday just helped make SNC’s business case a bit easier don’t you think?
Darkstar Says:
“How far away are we from a test launch?”
“Musk, the CEO of Space Exploration Technologies, says the first launch will happen soon after the Falcon Heavy arrives at the company’s launch complex at Vandenberg Air Force Base, California, late next year.”
“Soon” can mean many things. If SpaceX follows their normal approach, they’ll deliver the FH hardware and conduct a lot of tests. They’ll integrate the hardware and erect it on their launch pad. They’ll have fueling tests and validate their prelaunch checklists. They’ll need to validate the launch control software can successfully control and monitor the startup sequences for 27 (!) engines so expect at least one static fire test. My guess is that “soon” will likely be around 6 months from the time the hardware arrives at Vandyland and the first launch attempt.
The second stage makes orbit. The hopefully-reusable boosters are dropped ASAP.
How close does the -first- stage, the central F9, make it to orbit? Or, at least, what’s its velocity at separation? Or, perhaps, launched with a minimal/non-existant “second stage”? It’s completely full of fuel at booster-burn out.
If the upper stage isn’t added at launch, or is simply an aerodynamic-improvement of no major weight, is it possible that the central core could be making orbit? How much extra fuel would be needed if the ‘second stage’ were re-added as yet-another ‘extended range tank’? With 9x re-ignitable engines, the tanks, and the designed-in ability to refuel (under thrust, admittedly), it’s already a start on a very large EDS -or- a depot.
After three missions, attach the three cores into the FH ground configuration.
What kind of technical risk is the cross feed of fuel from the boosters to the central motors? I’m assuming there is still some fairly serious engineering to work out with regards to the pump, valves and fuel lines so that it all works smoothly during staging. Or, is switching fuel sources in flight pretty much a known quantity in rocket design?
There is no switching of fuel sources. Presumably the pumps have two outlet lines — one to the engines and the other to the center core. If everything is running smoothly the back pressure from the continually full center will ensure that the power heads get the inlet pressure they need in the side cores. When the sides are empty, the engines shut down and they separate, including the umbilical (just like the ET from the Orbiter).
Cross feed isn’t a new idea — we were looking at it in the eighties at Rockwell (and I’m sure a lot were doing so earlier as well), but this will be the first actual implementation of it that I’m aware of.
I’m thinking that the improved Merlin engine is going to find its way to the Falcon 9, and a Falcon 9 stretched in in the cards with 40% improved payload over the original.
IANAE, but this crossfeed looks like something else that could go wrong under stress.
How far away are we from a test launch?
Did Elon use the 95,000 lb thrust figure for the Merlin 1C in the press conference yesterday? I’ve seen that reported a few places, but SpaceX’s site says it’s 125,000 lbs.
95k is the figure for the current engine, 125k is their previous estimate for the upgraded engine
“I’m thinking that the improved Merlin engine is going to find its way to the Falcon 9, and a Falcon 9 stretched in in the cards with 40% improved payload over the original.”
I heard the Falcon 9 Improved was now rated to 16 tons to low orbit.
Assuming the now longer Falcon 9 can handle the bending and flexing cause by having a spaceplane on top, it should be able to boost Dream Chaser now.
Mass for the DC is 9000kg. The upgraded F-9 should be able to handle it in spades assuming the above stipulations can be met. Even give a bit of margin for mass growth and engine out too.
Yesterday just helped make SNC’s business case a bit easier don’t you think?
Darkstar Says:
“How far away are we from a test launch?”
IIRC, 2013-2014. From Wired
“Musk, the CEO of Space Exploration Technologies, says the first launch will happen soon after the Falcon Heavy arrives at the company’s launch complex at Vandenberg Air Force Base, California, late next year.”
“Soon” can mean many things. If SpaceX follows their normal approach, they’ll deliver the FH hardware and conduct a lot of tests. They’ll integrate the hardware and erect it on their launch pad. They’ll have fueling tests and validate their prelaunch checklists. They’ll need to validate the launch control software can successfully control and monitor the startup sequences for 27 (!) engines so expect at least one static fire test. My guess is that “soon” will likely be around 6 months from the time the hardware arrives at Vandyland and the first launch attempt.