A piece of Aerojet artwork depicting the NERVA nuclear rocket engine heading to Mars. This is almost certainly artistic license as the vehicle depicted here is a single stumpy upper stage with an aerodynamic fairing. This is mot likely a RIFT (Reactor In Flight Test) configuration, a simple expendable upper stage test configuration meant to be launched atop a Saturn V to prove out the engine.
The NERVA nuclear rocket, studied throughout the sixties into the early 1970’s, would have been a great way to propel spacecraft. But a nuclear rocket is not the same sort of reactor as is generally designed for use in space to generate electrical power. A NERVA can produce *gigawatts* of thermal energy, energy which is carried away with the high mass flow rate of the hydrogen propellant. Power reactors, on the other hand, are generally designed for several orders of magnitude lower thermal power… a few thermal megawatts, perhaps, to produce a few hundred kilowatts of electricity.
However, the fact remains that a nuclear rocket *is* a nuclear reactor. For most missions it would burn for a few minutes, at most perhaps few hours, out of a mission lasting perhaps years. It is thus a bit of a shame to waste all that potential. So over the decades many studies have been made for using a nuclear rocket as a power generator .
One such study was reported by Aerojet in 1970. The abstract is HERE, the direct PDF download if HERE.
In this study, the NERVA would pump out 1,500 thermal megawatts during the propulsion phase(producing 75,000 pounds of thrust), dropping to 250 to 505 thermal kilowatts during the power generation phase, enough to create 25 kilowatts of electricity. This would be a very low-power, low-temperature use of the reactor, reducing system efficiency… but still, making use of a reactor that was already there, and not noticeably using up the fission fuel in the reactor. The reactor would be run at very lower power levels and hydrogen would flow through a closed loop built into the reactor; the warmed gaseous hydrogen would flow through a turbogenerator to create electricity; the warm hydrogen would then pass through a radiator built on the outer surface of the hydrogen tank itself.
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A 1963-vintage NASA illustration of the NERVA nuclear rocket engine. This is schematic only, depicting the main components of the nuclear engine. Not labeled are the two vernier thrusters; these take the otherwise wasted hydrogen exhaust from the turbopump and direct it more or less aft for some additional thrust. Further, they could, unlike the main engine, gimbal; this would provide a measure of thrust vectoring.
From the NASA HQ history office, a NASA chart illustrating the NERVA nuclear rocket as of 1968.
A NASA illustration of the NERVA nuclear rocket, dated December 1963. Near the top of the engine are two vernier rocket nozzles for thrust vector control.
If NERVA is a subject of interest to you, I have scheduled a trip to Washington D.C the last week of March for the express purpose of spending an entire business week in a NASA archive doing scanning and photocopying and photoing of as much as I can, starting with NERVA, moving to SPS and then to early shuttle concepts. I’ve visited this archive before, always for no more than a day, and that was only enough to show me that they had a lot, not enough to let me actually copy what they had. This time will be different. To help me pay for the trip (travel is *not* cheap these days), I am taking subscriptions or investors or whatever you want to call it. If you give me $100, when I return I will send you DVDs that will include all scans, and scans of all photocopies, and all photos taken at the archive. This offer is good up to the time I leave; once the trip is underway, it will be closed. If interested, either comment here or send me an email: scottlowtherAT up-ship.com
You can download a 13.4 megabyte JPG file of the illustration. The link to the JPG file is HERE. To access it, you will need to enter a username and password. These are available on the first page of the Aerospace Projects Review V3N2 Addendum (available HERE) Note that both are case sensitive.
I’m selling the blueprints I’ve recently made. I can sign ’em if the buyer wants, front or back…
The rewards for November, 2021, have been sent out. Patrons should have received a notification message through Patreon linking to the rewards; subscribers should have received a notification from Dropbox linking to the rewards. If you did not, let me know.
Document: “Galactic-Jupiter Probe Program Concept:” 1967 NASA-Goddard brochure describing a Pioneer/Voyager type of space probe
Document: “Mixed Mode Rocket Vehicles for International Space Transportation Systems,” 1973 paper describing modified Shuttles and other launch vehicles
Document: “Nuclear Physics Made Very, Very Easy,”1968 NASA NERVA test operation publication that summarizes nuclear physics
Diagram: Navalized Advanced tactical Fighter (Northrop NF-23) general arrangement
CAD Diagram ($5 and up): “Disney Bomb,” British designed and built, American dropped rocket-boosted submarine pen penetrating bomb from the end of WWII
If this sort of thing is of interest, sign up either for the APR Patreon or the APR Monthly Historical Documents Program. *ALL* back issues, one a month since 2014, are available for subscribers at low cost.
This is what a manned mission to Mars dating from the late Apollo era would have looked like: a cluster of hydrogen tanks with a small number of NERVA nuclear rockets. The spacecraft would have been relatively gigantic as it leaves Earth orbit; large enough that it would have been assembled in space from at least six Saturn V launches. When it returns to Earth it would have been little more than the mission module; this would blast past Earth and continue in solar orbit while the astronauts and a few trifling hundreds of pounds of Martian souvenirs would have plowed into Earths atmosphere in a compact entry capsule. The mission module itself is described fully and heavily illustrated in US Spacecraft Projects #3.
I’ve uploaded the full rez versions of these renderings to the 2018-11 APR Extras folder on Dropbox, available to all APR Patrons at the $4 level and above. If this sort of thing is of interest, please consider signing up for the APR Patreon.
Found on ebay: a piece of B&W art depicting the Saturn V. The provenance is uncertain… unknown where this art originated. There are some unusual details; the tailfins are clocked 45 degrees off, moved from the outer diameter of the engine firings to between them, an odd choice to say the least. The third stage is larger in diameter than the S-IVb with a very long interstage between the S-II and the S-IVb; this *may* indicate that the third stage was meant to be a nuclear stage, with a single NERVA engine attached to the rear of the S-N third stage. The payload is also different: it appears to be a direct lander… no LEM, the Apollo vehicle landed directly on the lunar surface.
A number of vintage 8X10 glossies of aerospace concept art (all apparently North American/Rockwell) were recently sold on eBay. These included Apollo/Skylab, early Space Shuttle concepts, advanced spacecraft (including a manned mission to Jupiter and NERVA tugs) and various space probes and space station designs. Fortunately, the seller provided fairly good scans. I have collected them and uploaded them to the APR Patreon Extras Dropbox folder for 2017-05. If you are interested in accessing these and other aerospace historical goodies, consider signing up for the APR Patreon.
