Author Archives: johnhare


About johnhare

I do construction for a living and aerospace as an occasional hobby. I am an inventor and a bit of an entrepreneur. I've been self employed since the 1980s and working in concrete since the 1970s. When I grow up, I want to work with rockets and spacecraft. I did a stupid rocket trick a few decades back and decided not to try another hot fire without adult supervision. Haven't located much of that as we are all big kids when working with our passions.

Refueling for the Secondary Mission

It is fairly obvious that there are many benefits to having refueling capabilities in space. Perhaps not to the monster rocket fanatics with blinders and a few others, but to most of us it approaches no-brainer territory. The problem is … Continue reading

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Lunar Foxhole

Rereading some of the older posts on Lunar exploration, I ran into a lot of discussion on short term vs permanent outposts or bases. The assumption seems to be that short sortie missions will have minimal or even no radiation … Continue reading

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Missing Destination, Missing Opportunity

It looks to be months from the time that SpaceX claimed to have solved the problem that caused the vehicle loss of September 1 until the actual return to flight. There are stories to the effect that the delays are … Continue reading

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I reread several times Jons’ post on NASA under the next administration that recommends against having NASA focus on anything one finds important. I think he made good points throughout and it should have made for lively discussion. I didn’t … Continue reading

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Reverse Rocket

This is a post about an idea by Doug Plata. His idea is to put multiple propellant tanks on top with just enough structure to keep them intact and drop them in pairs as they drain. Under the tanks is … Continue reading

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Getting My Numbers

This is an explanation of how I get BOTE numbers for such things as the comparison between LH2 and CH4 propellants as in Jons’ last post. The focus Jon had was how much H2 do you need to carry to … Continue reading

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Semi-Staged Combustion

It is interesting comparing the two best known first stages in the US that use kerosene and LOX. The Atlas 5 and the Falcon 9 use a similar fuel in their first stages and then diverge in the technical aspects. … Continue reading

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Electric Inducer Pump

It takes pressure in the tank to suppress cavitation in the pumps for rocket engines. It is customary to use helium for most pressurization due to its’ low molecular weight. Unfortunately, it can take a lot of helium in some … Continue reading

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Notchbell Nozzle

Several years back I suggested a type of compensating nozzle that should be inexpensive to build and test. Unfortunately the ones I made for demonstration with compressed air were hit and miss as I didn’t have the theory quite right. … Continue reading

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Old Engines

Some before, and many after the accident criticized the use of old engines for the Antares. Many references were made to the long storage time with some mention of them as antiques. The refurbishment of these engines didn’t seem to … Continue reading

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