DaveyJ576

It is my understanding that the issues were related to speed. The very high speeds of the M-21/D-21 and the XB-70/X-15 greatly magnified the issue. The 747/shuttle combo was fairly low speed/low altitude and thus it was manageable. Remember that the shuttle had to be fitted with a tail cone for ferry flights, and on the ALT flights without a tail cone the 747 struggled with vibration and drag issues.

I am running the risk of raining on your parade, but Dennis Jenkins and Tony Landis stated in their book that the XB-70/X-15 combo was never given serious consideration. While the advantages of this type of air launch were well understood, the high speed physics of separating the X-15 mounted in piggyback mode scared the crap out of everyone. There had been a fatal accident with the SR-71/D-21 combo at separation, and even the successful releases were always quite sporty. After the initial concept look, the XB-70/X-15 idea was quickly dropped and never revisited. Even the drops from the B-52 were not smooth. The X-15 got a bit squirrely right at release due to air flow off the trailing edge of the 52’s wing. The X-15 pilot had to fight it for a few seconds to prevent a potentially disastrous recontact with the 52’s fuselage and wing. On the other hand this is KSP after all, and I don’t think Jeb et al. are worried about a little bumping and shaking… Correction… It was actually an A-12 variant called the M-21 that launched the D-21 drone. The A-12 was the precursor to the SR-71.

Wow! I consider that to be a sincere compliment and I appreciate it. Thank you. It may surprise you to know that my area of military expertise is in submarines, the exact opposite of rockets. If you are interested in that sort of thing (I apologize for going off topic here) check out my website: PigBoats.COM My only real spaceflight qualifications come from watching Neil and Buzz on TV as a kid, and an insatiable curiosity about spaceflight that came from that experience. I am a well-informed amateur and nothing more. That is why I enjoy KSP/BDB so much. It allows me to exercise that fascination anytime I want. BTW, I have always thought submariners would make GREAT astronauts. (Insert shout out to Steve Bowen and Kayla Barron here)

You know, I honestly never noticed the old Atlas-style avionics fairing on the Atlas V until I saw these renderings. Just to satisfy myself I went back to the NSF pages and sure enough there it was. Excellent work as always @Zorg. The entire BDB dev team should take a great deal of pride in how far the team’s modding skills have developed over the years. I started flying BDB back in 2019 when you were still on some of the old models. The photo-realism of what you produce now is simply stunning. Thank you! @CobaltWolf, @Invaderchaos, @Rodger

Very well done! Your TUFX profiles rock!

Done! I also lightened the LM ascent stage a tad. It is way heavy. Difficult to make it to lunar orbit in KSRSS as it stands originally.

It’s a great mod, but it needs a little TLC to bring it up to BDB visual standards. Overall it flies well, but beware of bringing it back from the moon. The heatshield can’t handle lunar reentry speeds. One of the best things about the mod is that the 1962 “Bug” LM is included! It interfaces well with BDB.

Two LMs and extra fuel in one launch? Seriously impressive job of rigging there shipmate!

Do you have a visual representation of the S-IVC that you are referring to? What were the engines, J-2s?

I have kitbashed a Titan II first stage derived launcher for a side mounted X-15. I am still tweaking in the design, but I did successfully fly a Cape Canaveral to Wallops mission and put her down on land, just short of the runway. Am having a weird substantial pitch up transient just as the booster is running out of propellent and haven’t figured out why yet. Once I have it dialed in I will post pictures.

Nope! My download is four days old. Missed it by that much! LOL. Thanks.

@Zorg, for the Atlas LR-89 booster engine, you have two of the engine selections that are the same. There are two buttons for the NA3 version and none for the NA5. The LR-105 is okay. FYI.

Download from Github (see the original post on page one for the link), unzip, copy the Bluedog_DB folder that is in the Gamedata folder, paste it into your Gamedata folder. It is literally that easy. The most current dev version is the 1.14-Development branch. Be advised that some elements of that branch may not be finished. The full release is Master branch, which is also downloadable via CKAN, but you won’t have all of the newest stuff.

Thanks! Don’t sweat the message thing. If it is a pain don’t bother.

@Zorg, having a great time with the new Atlas parts! One question so far... the Atlas SCORE doesn't seem to have any attitude control once the engine cuts off, i.e. no reaction wheels. Is this intentional? I fly it to orbit using the classic Mechjeb profile and it will not maneuver to the node necessary to complete the burn to orbit. I added a set of reaction wheels and it works great. Also, how difficult would it be to add a nifty little message to display when you click the "Transmit Data" button? Perhaps a shortened version of Eisenhower's speech that it transmitted IRL? Thanks.

@Zorg, how will the new Atlas parts effect my existing Atlas craft files? Will the new stuff cause conflicts with my craft files? I have no problem deleting them as I enjoy the build process. Thanks.

TITAN 3A The Lincoln Laboratory at the Massachusetts Institute of Technology produced a series of communications test satellites in the mid to late 1960's. These craft were intended to test out techniques and technology for future military communications satellites, and thus the effort was sponsored by the U.S. Air Force. At about the time that the first two sats were being completed the Air Force was putting into service the Titan 3 program which was supposed to be a standardized, flexible, and low-cost space launch vehicle. The initial version was the Titan 3A, which consisted of a Titan II core vehicle structurally strengthened to handle the coming side mounted solid rocket boosters, topped by a new upper stage called the Transtage. The first two flights did not carry a payload and were intended to test the new Transtage third stage. The third flight carried the first Lincoln satellite, but it was not entirely successful due to a fault in the Star 13 kick motor attached to the satellite. On May 6, 1965 the fourth and final test flight of the Titan 3A took place from LC-20 at Cape Canaveral. Further flights of the 3A were not needed as the program was moving on to the SRM boosted Titan 3C. The payload for this mission was the second Lincoln Experimental Satellite (LES-2), and a simple radar calibration spacecraft, a reflective sphere named the Lincoln Calibration Satellite (LCS-1). Launch, liftoff, and the flight through staging went well. The Transtage inserted itself and the payload into a 1200 km parking orbit. After insertion into orbit, LCS-1 was released, followed shortly after by LES-2 and its Star 13 kick motor. The kick motor pushed LES-1 into an elliptical orbit where it extended its antennas and began its mission. LES-2 is long dead, but LCS-1 is the oldest spacecraft still in use, regularly being pinged by military defense radars so that they can be properly calibrated. My kitbash of the LES used a Coatl Toreka core, with stock solar panels and structural elements around it. I picked a variety of antennas to give it some functionality. Admittedly it is a bit bigger than real life, as I am not well versed in scaling. The LCS sphere is a Near Future tank with a radial decoupler attached to it, which was rather difficult to get in the right spot on the SAF fairing base. I love the utility of the Agena, but the Transtage is a handy little upper stage with a lot of capability, and it looks cool in its stubby way. All in all a fun build, showcasing a little-known Titan variant. Now, onto @Zorg's new Atlas stuff! Can't wait!

MERCURY JUPITER In the late afternoon of October 19, 1961, NASA launched the final suborbital mission of Project Mercury. Mercury Jupiter-2 was intended to put a Mercury spacecraft on a high speed, high altitude flight as a final test of the heatshield prior to the start of the orbital missions. Air Force Captain Michael Alfred Robert Sampson and his spacecraft "Delta 7" flew a highly successful mission, despite some minor technical issues that delayed the launch and resulted in a twilight splashdown 1450 miles downrange, 700 miles northeast of Puerto Rico. After clearing some issues with the booster, the Launch Director made the call for the late afternoon launch, clearing it with NASA HQ and the Navy recovery forces. The launch and ride up hill went without a hitch. The spacecraft separated from the Jupiter booster on time, with the posigrade rockets pushing it clear. Sampson immediately rotated to retrograde and conducted a goo experiment. He had a beautiful view of the Atlantic and the northern Caribbean islands through the periscope as they passed below. Retrofire occurred 30 seconds prior to apoapsis, with the maximum altitude reached being 149 km. A clean separation of the retro package occurred and Sampson endured a crushing 9.5 Gs for a few seconds as the spacecraft entered the thickest part of the atmosphere. Twilight over the Atlantic provided a beautiful backdrop as the drogue stabilized the falling Delta 7. A HSS-1 Seabat helicopter from the USS Lake Champlain captured a memorable photo of Delta 7 descending under her main parachute, with the landing bag fully deployed. The antenna fairing can be seen in the background, coming down under the now discarded drogue chute. Everyone at the Space Task Group, NASA, and the astronaut corps was very happy with the flight and were looking forward to the orbital flights with the Atlas.

Very impressive work @Zorg. Really looking forward to this. @Friznit, looks like you have some work here for the Wiki, but for a good reason!

I have flown hundreds of Gemini missions with the BDB heatshield with no issues. Could you be more specific as to what you are doing?

If you like that one, try the space shuttle set. Imagine Hypersonic multiplied by three! It is mind blowing!

For those of you interested in the X-15 (who isn’t???), I can highly recommend the book Hypersonic: The Story of the North American X-15 by Dennis R. Jenkins and Tony Landis. It is THE authoritative reference to the aircraft and program, no other book on the subject is necessary, except perhaps for their companion book, the X-15 Photo Scrapbook, a collection of photographs that they weren’t able to fit into the book. Both books are out of print, but copies can be found for reasonable prices. Jenkins is also the author of the three volume magnum opus Space Shuttle: Developing an Icon 1972-2013. The X-15 book has an exhausting amount of detail, but is well written and readable.

I believe that 4g was picked for booster skirt sep because that is an authoritative structural limit for payloads. Anything higher than that and you risk damaging your satellite, or your living pilot. Admittedly, Al Shepard withstood 6.3g going uphill and 11g for a short period on reentry on MR-3, but both peaks lasted just a few seconds, and he was barely functional during those times. Sustained 4g is something else altogether.

I agree about PVG. If you set the orbital parameters too low for the power of your rocket, PVG does some weird stuff, like excessive pitch down and nearly horizontal flight at 20km. I use classic ascent and have no issues getting to orbit on 2.5x KSRSS with the BDB Mercury Atlas. I have found over literally hundreds of launch attempts that MechJeb PVG has two pitch maneuvers during first stage flight on the ride uphill. The first one is shortly after leaving the pad based on your inputs. The second will come higher up, typically in the 15-25km range. If the 2nd pitch maneuver is excessive, resulting in nearly horizontal flight or actual below horizon flight, your apoapsis (aka apogee) parameter is too low for your rocket. I saw this a lot while developing an Excel spreadsheet for optimal launch profiles for the BDB Saturn IB. I set the Atlas booster jettison at 4g for nearly every flight and I get acceptable performance. @Friznit has a table of Atlas performance on his BDB Wiki if you want truly dialed in performance.

Actually, the Navaho booster looks a lot like a Soyuz strap-on booster.