I didn’t realize till I saw it on NASASpaceflight.com, but apparently the panel I was on at NewSpace 2012 is now up on youtube, so I figured I would share. My piece runs from about the 8min mark till around the 14min mark, so it’s fairly brief:
Not sure if what I had to say adds much to the conversation, but I’ve been too busy to blog as frequently, so I figured I’d toss these latest thoughts up and see if any of you have any comments or feedback?
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President/CEO at Altius Space Machines
Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and is the founder and CEO of Altius Space Machines, a space robotics startup in Broomfield, CO. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew. Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
Latest posts by Jonathan Goff (see all)
- Fill ‘er Up: New AIAA Aerospace America Article on Propellant Depots - September 2, 2022
- Independent Perspectives on Cislunar Depotization - August 26, 2022
- Starbright Response to ISAM National Strategy RFC - July 2, 2022
Another bit of useful discussion here, regarding flight rates
I think the idea of smaller component payloads for in-space hardware, regardless of whether they are satellites or experiments or anything, will keep meeting a lot of resistance just because that not how things have been done in the past ( ignoring the entire assembly of ISS of course )
I.e. if you had a 100-pound to LEO RLV, that is actually super cheap per pound, it will probably a very hard sell to launch a earth observation sat on it in 3-4 pieces, like for example launching its solar array separately and stationkeeping propellant.
Thanks for the comment. I do agree that there’s likely going to be some resistance to “assemble in space from small components” from some directions. I should point out though that SkyBox and Planetary Resources are both looking at 50-100lb class earth observation satellites (though they’re both preassembled on the ground), so having a 100lb class RLV doesn’t preclude you from servicing a lot of interesting new smallsat markets. That said, I think that the ability to do low-cost assembly of small sats is the kind of disruptive technology that will most likely get implemented servicing new markets that couldn’t be serviced using the old paradigm.
That enough buzzword bingo on my part?
“I.e. if you had a 100-pound to LEO RLV, that is actually super cheap per pound, it will probably a very hard sell to launch a earth observation sat on it in 3-4 pieces”
If it already existed, and was known to be extremely cheap, then small innovative players would exploit the capability even when the major satellite makers are shunning it as not-how-things-are-done. Eventually those small players grow up enough to start stealing customers from the majors. Then the majors will adopt the new technology in a rush (or will be replaced.) So I don’t think there’s any danger of any low-cost-per-pound RLV failing for a lack of customers.
The danger is when there is a potential for a cheap low-mass launcher. But to get there you need enough investment, and enough customers, to develop the technology. And those customers/investors have to come from traditional markets. That’s where that resistance to innovation will kill you.
Thanks for the link to the video. An interesting advantage of propellant depots is that they would also allow SSTO’s to also be roundtrip lunar transport vehicles. That is, a vehicle with sufficient delta-v to be SSTO from the Earth’s surface to LEO, would also have enough delta-v if refueled in LEO to fly to the Moon, land, take-off and return to Earth all on the one refueling.
This is not true for a TSTO btw. The reason is the first stage takes up a big chunk of the delta-v to orbit for a TSTO. So the upper stage is well short of the delta-v to reach LEO on its own. But the round trip to the Moon delta-v is close to this value so the upper stage also could not do the round trip to the Moon on only one refueling.
See discussion here:
The Coming SSTO’s: Applications to interplanetary flight.
The feasibility of SSTO’s is still doubted by some. But SpaceX claims the Falcon Heavy side boosters will have a 30 to 1 mass ratio. If true, then simple application of the rocket equation shows it can be SSTO with significant payload.
And Jon mentioned in an earlier post from 2006 that work by ULA suggests that switching to lightweight Al-Li alloy for the Centaurs can give up to a .95 propellant fraction, corresponding to a 20 to 1 mass ratio:
Centaur Based Earth Departure Stage.
Nov 16th, 2006 by Jonathan Goff
A hydrolox stage with a 20 to 1 mass ratio can carry significant payload as a SSTO.
In the video Bernard Kutter gives a talk on Centaur derived cryogenic upper stages at about the 28 minute mark. He notes the key variable that determines capability is the mass ratio and argues in favor of methods to maximize it for cryogenic stages.
I’m arguing that a kerolox stage with a 30 to 1 mass ratio, corresponding to a .97 propellant fraction, is likewise of major importance, which however is not yet fully appreciated.