Blue Origin has successfully tested its new hydrogen/oxygen rocket engine.
The competition heats up: Blue Origin has successfully tested its new hydrogen/oxygen rocket engine.
This would be the second new American rocket engine since the 1980s, following SpaceX’s Merlin engine. That it uses hydrogen/oxygen is also significant, as these fuels provide the highest ratio of power to weight. (As far as I remember, the shuttle was the only other spacecraft to use hydrogen/oxygen.)
Post corrected. Thanks Paul!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
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"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The competition heats up: Blue Origin has successfully tested its new hydrogen/oxygen rocket engine.
This would be the second new American rocket engine since the 1980s, following SpaceX’s Merlin engine. That it uses hydrogen/oxygen is also significant, as these fuels provide the highest ratio of power to weight. (As far as I remember, the shuttle was the only other spacecraft to use hydrogen/oxygen.)
Post corrected. Thanks Paul!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Other way round, Bob! Highest power to weight ratio
I thought one of the engines used on Apollo was a Hydrogen/Oxygen engine (maybe not the main engines on Saturn V though) – ?? Anyone know?
LH2/LOX offers the highest ISP of commonly used rocket fuels.
Lots of US engines us Hydrogen, but not so many first stages.
Off the top of my head:
J2 – used on upper stages of Saturn V
RS-68 – Delta IV first stage
RL10 – Used in the Centaur upper stages, Saturn I, Atlas, Titan etc… Still used on Atlas V and Delta IV upper stages.
Thanks for that info Patrick – I figured someone here would know! This site is such a great resource – so many knowledgeable folks here. BTW – why are Hydro/Oxy engines used only for upper stages & not for main booster engines?
Some first stages use LOX/Hydrogen, notably the RS-68 on the Delta IV and the SSME on the space shuttle.
As to why LOX/LH2 is best suited for upper stages: as I understand it high thrust beats out efficiency on the first stage but lower gross weight and higher efficiencies win out once you’re in vacuum.
This favors RP1 for first stages and LH2 for upper stages.
This isn’t a hard rule and the devil is in the details. The Russians use RP1 on almost all their stages (I believe Energia was the exception).
… high thrust beats out efficiency on the first stage but lower gross weight and higher efficiencies win out once you’re in vacuum.
Makes sense to me – thanks !
Come to think of it, with the weight of all the propellant & large 1st stage at the start of the launch, a little extra engine weight would probably be more or less negligible. Once most of that is consumed & the vehicle’s outside most of Earth’s atmosphere, the remaining stage(s) & fuel would weigh much less (booster stage long gone at that point), the engine weight probably accounts for a bigger % of the total remaining vehicle weight & therefore makes a bigger impact on performance…