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Old 07-26-2019, 08:23 AM
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blackshire blackshire is offline
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Default SLS delayed again...

Hello All,

Scott Manley, a reliable space reporter, historian, and analyst, has said *here* www.youtube.com/watch?v=ba087WZHXZE (at the 3:50 point of the 6:19 video) that the SLS has been pushed back yet again—now to 2021. I’m not surprised, given that the NASA administrator pleaded for additional funding a few days ago, so that the vehicle could (hopefully) be ready in time to meet President Trump’s firm “boots back on the Moon within five years”—by 2024—schedule (Vice President Pence has repeatedly reminded NASA that if their hardware isn’t ready, privately-developed hardware will be used instead). Having a definite date focused NASA on the "Kennedy goal" with Apollo; both before and after Apollo, the lack of a firm "do-by date" for big projects such as that resulted in incremental progress toward an indefinite future implementation date. Also:

Since the SLS is a creature of politics (NASA was never very wild about building it, and even submitted its “just one launch every few years” schedule to, in part, discourage the Congress from supporting it—but the Shuttle-building legacy aerospace firms lobbied key Senators hard enough, hence the vehicle’s nickname, “Senate Launch System”), now is the time to pull the plug on the whole sordid mess (the upcoming BFR--or even multiple Falcon Heavy launches--could achieve the 2024 goal, including the Gateway station). With the recent deficit-ignoring two-year budget deal (in which the nation’s debt ceiling won’t be raised during that period—many Republicans, including the President, don’t like it for that reason), the President has the perfect excuse for ceasing to throw any more good money after bad with the SLS. The SLS’s planned CubeSat-size payloads—including the solar sail NEA Scout asteroid probe—could instead fly, and sooner, as “hitch-hiker" payloads on Falcon 9 and/or Falcon Heavy (or Electron, perhaps as primary payloads) flights, and:

To reduce the bitterness of that medicine, the development of the reusable and man-rated—but to be discarded, on SLS missions—RS-25 (the modified SSME [Space Shuttle Main Engine] used on the SLS core stage) and RL10C-3 (for the SLS second stage) could be continued, to simplify their construction (lower parts count, fewer welds, etc., by using 3D printing—this is already being done with the RL10) and improve their performance, as both rocket engines would have many uses in future reusable launch vehicles and space tugs. Both rocket engines could also be used (including simultaneously, in the same vehicle) to power smaller, air-launched orbital spaceplanes. For example:

Teledyne Brown Engineering’s Spaceplane (designed by Dan DeLong) was an unpiloted, 747-launched vehicle powered by one SSME and four RL10s (both engines could safely be ignited at 30,000 feet with their vacuum-optimized nozzles, with no flow separation problems), which had a shortened (21’ long), Shuttle Orbiter-size cargo bay, containing all of the standard Orbiter payload interfaces. It also had the capability, if its SSME failed to ignite (the RL10s effected separation, to protect the 747's tail fin from the SSME's exhaust plume; it was to ignite seconds after 747 separation), to autonomously fly to an abort airfield under the power of the RL10s, on a course designed to expend the excess propellants en route. Plus:

Numerous SSTO and TSTO (winged as well as ballistic) launch vehicles, manned and unmanned, and of various sizes and payload capabilities, could use both engines. These include vertical takeoff & landing vehicles such as MBB’s (of Germany) BETA and BETA II plug-nozzle vehicles. Their designs used ordinary bell-nozzle engines, thrusting through openings in the bottom combination heat shield/plug nozzle; at higher altitudes, the engines’ expanding exhaust plumes pushed against the bottom of the vehicle, increasing its thrust and therefore its performance. The RL10 would also make an excellent reusable space tug engine (in the 1970s NASA developed not only space tug designs, but [for manned planetary missions--Luke Strawalker posted the report here on YORF] also a Saturn S-IVC LOX/LH2 stage—with much better insulation to greatly reduce propellant boil-off—several of which would have been “stacked” in tandem to form an “orbital launch vehicle” to boost heavy manned interplanetary spaceships out of Earth orbit). With today’s better insulating materials technology, such LOX/LH2 space tugs--and propellant depots in orbit--would be feasible.
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  #2  
Old 07-26-2019, 10:53 AM
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Jerry Irvine Jerry Irvine is offline
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So, since this will be a recurring news item, SLS delayed, maybe just bump this thread a couple times a year. Meantime Hopper (pre-Starship) has had hot fire tests of the first vehicle as of 7-19.

Jerry
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Old 07-27-2019, 10:26 AM
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blackshire blackshire is offline
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Quote:
Originally Posted by Jerry Irvine
So, since this will be a recurring news item, SLS delayed, maybe just bump this thread a couple times a year. Meantime Hopper (pre-Starship) has had hot fire tests of the first vehicle as of 7-19.

Jerry
That's what I'm afraid of, concerning the SLS--that it will just go on and on because it gives NASA something to do (in other words, NASA and NASA contractor jobs). It isn't even a well-optimized system, having mediocre payload capability for its size and cost. But more cheerfully:

Yes, I was very pleased to see SpaceX's Starship Hopper test vehicle make its first brief un-tethered flight (for anyone who may not have seen it yet, here's an article with included videos: https://spaceflightnow.com/2019/07/...hered-hop-test/ )! If it wasn't the first methalox rocket to fly, it has to be among the first. The complete vehicle's payload in orbit (the fully-reusable Starship second stage [with an integral payload bay], launched atop the reusable booster, called the Super Heavy) is 220,000 pounds (see: https://www.wikipedia.org/ [enter "SpaceX BFR" on the search line]). Also:

If it works as advertised, the BFR (Super Heavy/Starship) vehicle will make possible the construction of space colonies such as Kalpana One (see: https://en.wikipedia.org/wiki/Space_habitat ) and Solar Power Satellites (SPSs), using ^terrestrial^ material rather than material mined and electromagnetically shot from the Moon, which Dr. Gerard O'Neill's space colony and SPS studies showed to be necessary in the 1970s. This capability is specifically mentioned in the book, "The High Frontier: An Easier Way," by Tom Marotta and Al Globus (see: http://www.amazon.com/High-Frontier...y/dp/1719231745 ), and:

Back then, Boeing and Rockwell had developed designs for BFR-type, super heavy-lift SSTO and TSTO space freighter vehicles to support SPS construction (see: https://www.pmview.com/spaceodyssey...elvs/sld001.htm , especially the fifth section which is titled, "Solar Power Satellites (SPS) and Advanced Launch Vehicles"), but no hardware was built. The BFR will, hopefully, be only the first of a new type of launch vehicle, the true Earth-to-orbit (and beyond--the BFR's Starship stage is planned to be able to land on the Moon and Mars and return to Earth) freight and passenger spaceship. This picture of Elon Musk holding a model of Starship (see: https://en.wikipedia.org/wiki/BFR_(...)_(cropped).jpg ) is delightfully reminiscent of Tom Swift Jr. and his fantastic spaceship designs! :-)
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
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