Zeiss Ikon

Okay, I've "adjusted" the vessel -- there is no engine other than RCS quads on the payload, and the RCS wasn't even activated during launch and circularization (I included it mainly to have the ability to dock and recover the pod -- this is, at this point, effectively a light refueling ship, carrying 1800 units of LF/O with a docking port to permit transferring the fuel to another similarly equipped ship). I have screenshots of the complete vessel and "inert" payload (which includes Jeb in a Mk. 1 Command Pod, along with parachute to get him home -- I think I forgot a heat shield, but these can reenter from low orbit without one, if you keep your periapsis high). I've also got a screenshot of the complete vessel, in orbit, prior to staging away the booster. Here's the craft file. See below... "Payload" mass 14.690 t (Mk. 1 Command Pod, Mk. 16 parachute, 1.25 m decoupler, 1.25 m monoprop tank, 12x RCS quads, 2x800 size tanks, 200 size tank, two fuel cells, inline docking coupler, and 1.25 m probe core). Launch Mass 116.110 t (includes .2 t of launch clamps; also adapter tank (800 fuel units), 3200 tank, 6400 tank, and the integral 6400 tank for the Twin Boar) Obligatory launch pad shot... After MECO, waiting for apoapsis to circularize. Circularizing complete -- just a whisper of fuel left in the booster, payload fuel untouched. Map view showing both apses, verifying orbit within tolerance on both. Assuming I'm allowed to deduct the launch clamps, I get payload 14.690, GLOW 115.910, or a final payload fraction of 12.67% -- which I don't think is bad for a rocket-only SSTO. I'll be very disappointed if someone doesn't beat that figure with a multi-stage rocket (in fact, I might come back and do so).

Ugh. That means I have to go back and delete perfectly good engines. Even if I can show the rocket in the required orbit with the upper stage still attached to the booster (and hence upper stage engines never activated). Not to mention multiple screen shots throughout launch showing RCS off... Sigh. Okay, one dead weight payload, coming up.

Hmm. I've got a vessel in my Sandbox save for this challenge. Let me go make a couple minor mods (disabling engines in the upper stages to make them "payload") and take some pictures... I guess a crewed VTO LF/O SSTO with no stage recovery is "Rocket mode".

Physically impossible. When the Mun is full, its shadow goes out into interplanetary space. Geometrically, there are three days each orbit when Mun is further from the sun than Kerbin. In fact, there can only be a single eclipse (lasting as long as it takes Mun's shadow to cross Kerbin) once per "Munth", when Mun passes between Kerbin and the sun. Given Kerbin's rapid rotation, that eclipse may well be visible from every point on the equator, sequentially, when it occurs (haven't diagrammed Kerbin's rotation vs. Mun's orbit, to verify how long Mun's shadow takes to cross Kerbin) -- but I guarantee you there is only one (long) eclipse per Munth (6-ish Kerbin days)

Nah, can't be any more than every 6 Kerbin days -- once per orbit of Mun.

A year or so ago, it was tomato soup (made with milk) here. That keyboard never did fully recover, even with a full key removal cleaning.

For my own use, I like Poodles -- they're about as efficient as Terriers, but they have alternators (which is little help for long interplanetary flights, but useful if you're staying in Kerbin's SoI) and significantly more thrust. The final stage of my Rockmaster Mod. 1 (see my post of April 9 in What Did You Do thread) uses multiple Poodles to get about 1 G with full tanks, and a good bit more when close to empty, but everything it does could be accomplished (much more slowly) with a single Poodle (and the mass savings for deleting six engines would give Even More Delta-V). When pushing a thousand tonne asteroid, however, the extra thrust is very welcome...

I just finished my first successful asteroid mission (see my post in What Did You Do thread). I had no problem getting the Klaw to catch, and was able to successfully steer the captive rock (just over 960 tonnes of it) into a stable orbit around Kerbin. With chemical rockets only, no less (haven't unlocked NERV, not sure if I will)! Poodles rule (but be sure to bring enough of them). It still works, but you have to right-click on the asteroid, not on the Kerbal. I just got back from an asteroid mission where Luory collected such a sample. BTW, thanks for the tip on targeting center of mass -- it seems obvious, but if it's not automatic, I could easily have wound up doing nothing but spinning up the asteroid-vessel combination when I tried to boost it back toward Kerbin.

Sometimes encounters are hard, sometimes they're annoyingly hard to avoid. Seems like every time I want to go to Minmus or beyond, I have to take a sub-optimal maneuver on the way out or in just to avoid an encounter with Mun.

I've been short on KSP time lately, but I managed to get some play in this weekend. (Science Save) Headlines read: Hero Kerbonaut Returns, leaves new "third mun" in Kerbin orbit. After her last attempt to rendezvous with an "asteroid" during its encounter with Kerbin, Valentina had determined that the technology wasn't yet up to intercepting an asteroid in the very limited time frame (seven to twenty-some days) that it's within Kerbin's influence; she had vowed that the next attempt would take place beyond Kerbin's sphere, in orbit around the sun. Backed up with scientist Luory Kerman, riding as a passenger for most of the long voyage, and supported by the Design Committee and the crew at the VAB, she was as good as her word. The slide rule crowd spent a couple all-nighters modifying Far Traveler Mod. 3 (the vessel used for the last asteroid rendezvous attempt) to increase its already huge on-orbit delta-V as well as give it the capability to actually connect to an asteroid, should Val manage the rendezvous. The first item was managed by the simple step of deleting the heavy two-stage lander, thereby reducing the mass the transfer stage had to push by about twenty-seven tonnes. The second item required a piece of newly researched technology, a general-purpose attachment device commonly referred to as a "Klaw", which was mounted on nose of the command pod, where the docking port had been in the Far Traveler vessels. The combination allowed the vessel to still have a transfer stage burn time of around five minutes, but, with less mass to push, the ability to make a given maneuver with a shorter burn (or at lower throttle, if the crew needed a break from high acceleration). The resulting vessel was a little stubby, but Val's comment to the press was "I'm not flying her for her looks, I'm flying her for her legs." Launch to orbit was routine, with a standard equatorial orbit chosen in order to save fuel, and because with the mission leaving Kerbin's gravity well, tiny corrections later could make up for any inclination changes. The new ship, based as it was on a reliable design, flew predictably, and Val had about twenty percent fuel left in the booster core's seven tanks when she reached parking orbit. "Every meter per second counts," she told ground control as she declined to deorbit the booster core. She did, however, shut down three of the booster core's motors, in order to even out acceleration across the staging event in the ejection burn; this allowed a better calculation of burn time, thus better timing of the burn. That burn was uneventful, and left the remainder of the Rockmaster Mod. 1 on course beyond the orbit of Minmus, into the sun's domain. Once far enough from Kerbin to ignore its gravity, there followed a series of small corrections to refine the rendezvous with the chosen asteroid, LTY-758. One of these burns was less than half a meter per second, but changed the closest approach from more than four hundred kilometers, to less than seventy. Unavoidably, however, the journey was a long one. Despite choosing a target that was relatively close to Kerbin and in a similar orbit at similar velocity, Val and Luory had gone a quarter orbit around the sun before they caught up with the space rock. Once they did so they began the process of matching velocity -- very much like docking in Kerbin orbit, only with larger distances and over longer time periods. Val used the same trick as during the ejection burn, disabling some of the vessel's engines during the early part of docking, in order to save RCS fuel without needing fractional-second burns for relatively small velocity changes. Eventually, the rock was close enough to see by eye. By that time, Val had the Rockmaster's velocity very well adjusted, so all that was needed was to keep an eye on the nav ball and periodically nudge the RCS to reduce closing velocity (wouldn't do to hit hard enough to break the Klaw, after all this time and distance). By happenstance, their approach was from sunward of the asteroid, so when they got really close, they could see the shadow of their own ship cast on the space rock. One of the things about experience -- if you already have it, you don't feel like you need it. Val made the never-before process of docking with a primordial piece of the Kerbol system look as routine as docking the lander to the transfer stage for a Minmus mission. The grapple made contact, and locked onto the rock, and the ship's accelerometers automatically measured the rock's mass for burn time calculations: just under a thousand tonnes. Luory went EVA to collect a surface sample from the asteroid, and then they renamed it "Valentina 1" -- completely without any false modesty, everyone present agreed Val had earned it. There yet remained an important part of the mission: not simply to rendezvous with the asteroid (there had never been any doubt Val could do so, if her ship had long enough legs), nor even to dock with it using the new grapple system, but, if possible, to attempt to divert the rock in to an orbit around Kerbin. Luory claimed later that Val said to him, "Heck, we've already got three first-ever achievements this flight -- why not make it four?" A little care with the orbit plotting computer (on their own, since they were far beyond comm range from Kerbin, and had been for a quarter year by this time), and they had a Kerbin encounter with a reasonable periapsis, well within the orbit of Minmus. The question that remained was whether the (rather cranky, due to the flexbility of the grapple connection) composite vessel could be coaxed to boost long enough in the correct direction to get them home while pushing an irregular thousand tonnes of rock. Val had already noted that the automatic stability system tended to oscillate; she surmised this was because the reaction wheels and the flex of the Klaw combined to produce a sort of pendulum. For the first burn, that would boost the rock into a Kerbin encounter, she chose to maneuver the cumbersome load manually. Her light touch on the controls allowed bringing everything into line, pointed at the maneuver node, and she ran the engines at reduced throttle to reduce the likelihood that gimbal activation would fold the grapple. Though she ended up cutting the burn short by a few seconds (at the low throttle, it was less than two meters per second), she was still able to obtain an acceptable Kerbin periapsis, and then had another three quarters of a year transfer time to work out how to get the ship's control systems to play nice with a thousand tonnes of irregular rock. In the end, she found she could disable the large reaction wheel built into the transfer stage, leaving only the command pod's torque, and avoid oscillation. On that basis, when it came time for the capture burn into Kerbin orbit she also locked the gimbals on the six outboard Poodle engines, leaving only the center engine free to steer the rock -- and it worked. She was able to turn toward her maneuver nodes without oscillation, and boost at one third throttle (instead of the one tenth she'd used initially, to give herself reaction time for heading corrections) (though the final apsis adjustment saw some oscillation during the burn, everything held together). Due to delta-V limits, she was forced to leave the rock in a high, eccentric, and inclined orbit -- "Pretty nasty, but it's all you're going to get," was her reply to ground control when they mentioned the condition of the orbit. With just over 10% fuel remaining, she undocked from the rock (unfortunately, leaving it with a bit of a tumble, which will add challenge for the pilot chosen to correct the rock's orbit), backed clear, and set up the burn to drop the ship into Kerbin's atmosphere. With their high apoapsis, she made a conservative choice of periapsis, and wound up having to wait for a second pass to fully deorbit, but otherwise, reentry was uneventful. Despite carrying no instruments, Luory's surface sample, along with their various crew and EVA reports, brought back some useful data -- and the asteroid now known as Valentina 1 remains in orbit around Kerbin, at least if someone goes out and gives it a little push before it encounters Mun and gets ejected from Kerbin's influence. That will be quite some time (the orbit is close to 3:1 resonance with Mun, and not presently close to encounter), so there's no great rush.

It might be, but that's a pretty good size coffee urn, to weigh 4 kg.

There's also the little issue that the non-equatorial, super-GEO orbit of the asteroid would drag the suspension cables through the usual parking area for comsats. How to bring down everyone's television before you even finish construction...

Over the last few days, Valentina flew another attempt to intercept an asteroid. (Science Save) After the instrumentation problems on the previous mission (which had her setting up an intersect with an asteroid that wouldn't be there for sixty-some days), Val made some veiled threats in the hearing of Mission Planning members. They responded with ASA-666, which Tracking indicated was a strong candidate to collide with Kerbin approximately 26 days after her last splashdown. Fortunately, as a Class A, it was very unlikely to do serious damage unless it actually struck a populated area (with Kerbin's surface more than 50% water, and the relatively small number of actual cities, this isn't considered a large risk). The tricky part was that the predicted path was a retrograde hyperbola with an inclination of approximately forty degrees. A newly upgraded ship was available, however; Far Traveler Mod. 3 had seen the addition of a Mk. 1-2 command pod on the transfer stage, originally planned to contribute to more efficient landing missions beyond Mun and Minmus -- but which also simplified redocking after transposition of the lander, as the Transfer Stage Pilot could stabilize the stage while the Mission Commander handled the lander. For this mission, Sherny was chosen to accompany Valentina. Launch was uneventful, and once the initial ejection burn had been completed, giving the first hack at timing the intercept, Val decoupled the lander and redocked nose to nose, then transferred to the larger 3-Kerbal command pod. Then began the very uncertain process of trying to rendezvous with an object whose orbit wasn't very precisely known -- which, in fact, hadn't even entered Kerbin's SOI at the time of launch. The initial search orbit was five days to apoapsis, where Val made a burn to reverse the orbital direction to match the target's retrograde path. There followed a period of experimentation, culminating in a closest approach of approximately 420 km at about 370 m/s relative -- but, with only two days to predicted periapsis, it was clear that the object would, in fact, impact Kerbin, and that Val and Sherny would be unable to get closer without effectively diving into the home planet themselves. Once they'd passed their closest approach, then, they burned radial to reestablish a prograde aerobraking pass, which they used to lower their own apoapsis. They then lowered periapsis enough to allow reentry and landing, undocking the lander and staging away the transfer tanks and engines just as they entered atmospheric interface (to ensure those discarded bits would deorbit -- if not immediately, then within a couple orbits). With the science instruments on board the lander having been held in reserve in case they were able to closely approach the target, no experiments were returned to Kerbin on this flight, but Val expressed the need to change strategy for the next asteroid intercept mission. Instead of waiting for the object to encounter Kerbin, the next attempt will be to go out beyond Kerbin's influence, into the sun's orbit, in hopes that methods usually used to rendezvous and dock in orbit around Kerbin, Mun, or Minmus will be applicable.

Augmentors are cheap and lightweight, and do not need ramjet speeds to operate. Look at YouTube videos of pulsejets; they get significant thrust increase from very, very simple augmentors even in static conditions. I've also seen model rockets (Estes engines) built with augmentors, with experimental proof that the augmentor increased thrust as shown by increased acceleration at launch. As noted, the exhaust velocity is greatly reduced from any sort of well designed rocket engine, but the increase in exhaust mass (adding the mass of the air flow through the duct) keeps the effective Isp as measured with the rocket engine's fuel/oxidizer close to constant while increasing thrust by anywhere from 10% to 200% (strongly dependent on details of the duct design and operating conditions). Generally, I'd consider an augmentor to be a significant improvement for that part of a rocket's flight that's within the troposphere and stratosphere, up to whatever Mach number you can manage to keep the inlet duct from choking on its own shockwaves. Unlike a turbine engine's inlet, you won't want to slow the intake air below sonic speed; the faster the air is going when it mixes with the rocket exhaust, the faster the exhaust will be (and we all know faster exhaust is better, other factors equal). Also worth noting that if the flow through the augmentor is subsonic, it would be possible (at the cost of some complexity and weight) to inject fuel to make the augmentor function as an afterburner, which would increase both thrust and Isp.

Wow, I'm a piker. Mine is only about 1.9 GB. Then again, the only mod I'm running is Better Burn Time (which is tiny), and I don't have hundreds of monstrous .craft files -- probably less than a hundred of my own between two saves.

As I read the mentions of this, it requires editing the save file.

On the basis of a couple hundred hours flying radio control models, landing is the hardest part of flying. Aerobatics are easier. Soaring is easier. Taking off is only hard if your aircraft is underpowered. But landing is always stressful.

I'm aware of the cap-lock setting (and don't use it much, preferring light taps on the keys in regular mode). The problem I had in this case was that the combination of "point to target" on both transfer stage and lander led to the two circling each other and the rotation rate building up as I tried to translate the lander to get the stack-to-be straight enough for the docking clamps to latch. I'll find a suggestion thread to repeat this, but it would be very, VERY helpful if there were some way to indicate pitch and yaw axes on the spacecraft in the external view. The nav ball can say my vector is perfectly aligned, but if I'm approaching at an angle, I won't get a latch -- I'll get a bump that adds tumble to an unstabilized part, or a "tail chase" if both parts are on target point. And when I try to straighten out, the nav ball is no help. Yes, I know, there are mods for that, relative to docking -- but what I'm suggesting is that the ships have a clear indicator of pitch and yaw axis, which would be useful for any maneuver -- like getting into orbit the correct direction when launching from Mun, or launching to polar orbit from Kerbin.

Following up on this, when I redocked my lander (Mk. 1 command pod with Clamp-o-Tron Jr.) to my transfer stage (Mk. 1-2 command pod with Clamp-o-Tron Jr., even though the nose has room for the 1.25 m port), I found the flow priority was no longer what I set in the VAB -- the transfer stage's 2.5 m monopropellant tank had the same flow priority after redocking as the lander's four Roundified tanks, which would reliably result in the Roundified tanks (4x60 units) running dry while there's lots of fuel in the 2.5m tank (750 units). Oddly, at some time (possibly a game restart) after manually adjusting the flow priority, I found the transfer stage tank had regained its higher priority, plus the 10 priority units I'd added in my manual adjustment. I also found that this particular lander does use a lot of RCS fuel when docking to the transfer stage, even when the transfer stage is stabilized; apparently, the RCS isn't well balanced or my movements are fighting with the "point to target" SAS setting. Next time I fly this vessel I'll try to remember to set the transfer stage to "point to target" and then switch it back to "hold orientation" so I can dock to it without it turning to follow my every correction. Maintaining pointing has worked well in the past, but I've never had vessels with the mass distribution (base-heavy) that these do.

I'll try to give this a test, but it'll have to be during an actual mission -- Val has another date with an asteroid tonight.

Well, that was the idea. Of course, by the time Congress was done with it, the Shuttle cost more to operate than expendable rockets to do most of the jobs it was intended to do. Why would you need wings and a crew of seven to launch an interplanetary probe? After Challenger, they retasked it for only missions that required crew, and ISS operations -- and it still cost more per payload ton than it would have to use (for instance) a Titan with its man rating recertified and restart the Apollo capsule line. Not to mention that even before Challenger, they were spending delta-V after reaching orbital height and velocity to ensure that the ET burned up rather than leaving it in orbit, where it might have been possible to repurpose the spent tanks...

Hmm. I used to use manual shutoff before I discovered flow priority -- problem is, I had several instances (in my sandbox game) where I "ran out of monopropellant" only to later discover that I had about 2/3 of my original supply remaining in tanks that had been shut off. I suppose it's possible that I burned a lot more of the lander's monopropellant than I thought doing the turn-around and redock to the nose-to-nose configuration (during that operation, the transfer stage is unguided -- no probe core, no crew -- so it tumbles slowly). Once redocked, the transfer stage RCS tank is available again, which prevents me from noticing the state of the lander's tanks. I might have to reexamine my "no automation" policy for my science save -- or just put another command pod on the transfer stage so it can stabilize on a gyro heading and/or hold "point at target". That would save time as well as RCS fuel. Docking is fairly easy if both vessels can maintain target pointing; it's not terrible if one just holds orientation -- and it's a PITA if one is tumbling free (because every port bump that doesn't latch adds to the tumble). That transfer stage isn't intended to be recovered; if I put a command pod on it, I'm committing to at least bringing the command pod back (or I have to redesign the lander for one or more additional seats, and then scale up the launcher for the extra mass). OTOH, it is intended to bring the lander's ascent stage back to Kerbin from wherever the landing was done, so having a kerbal aboard wouldn't be completely off the wall. Hmmm. Back to the VAB, I guess...

A while back, I learned about setting flow control for resources that are shared over an entire vessel, such as RCS fuel. Today, however, I came to wonder if I knew what I thought I knew. My ship, Far Traveler, has a 2.5 m RCS tank in the transfer stage (250 units), four "roundified" external tanks on the lander ascent stage (60 units), and the usual 10 units stored in the command pod. On its first real mission, I never had a problem with RCS until after decoupling the transfer stage to test the lander during aerobraking -- and then I found out both the lander's roundified tanks and the small capacity of the Mk. 1 command pod were depleted. Now, either I ran everything dry just about the time I decoupled (unlikely, since I was turning off RCS between intentional uses to avoid having it cause orbit drift when used for stability, though I can't say I actually checked; last time I'd looked, after using RCS for a very, very small correction burn, there was about 40% left), or my flow priority (30 for the transfer stage tank, 10 for the roundified tanks, and -10 for the command pod's tank) worked backward from what I expect. Suggestions?

Last night and today, Val continued her assigned work. (Science game) While Munar Lander Mod. 2 was giving journeyman service for voyages to Kerbin's moons, R&D had kept remarkably close-mouthed about what they were working on. They had gobbled up a huge quantity of data taken from three Mun missions and two multi-landing Minmus missions since the last significant spacecraft or launcher upgrade, and rumors had started to circulate that they were spending their time eating pizza and playing video games. None of this was connected with Jeb's puffy eyes and drawn look; after all, he was close with a number of the R&D types; legend has it he was recruited by Werner himself. However, with the growing awareness of the magnitude of the potential threat posed by the new type of body the astronomers call an "asteroid" (because no matter how much magnification you apply, it still just looks like a star in the eyepiece at the limit of seeing quality), an R&D spokesman was authorized to reveal the previously secret subject of R&D's late nights and Jeb's fatigue: Far Traveler. This vessel was originally designed with its sights on Gilly, Ike, Duna, and Dres. It has more than 5 km/s delta-V in LKO while pushing the heavy upgraded lander, and the transfer stage uses seven of the new Poodle engines to get maximum use from its fuel, while maintaining the ability to thrust at nearly 1 gee with full tanks. The lander itself is good for more than 1.2 gee, and was extensively hover tested around KSC during development. In order to assure the (6) boosters fall clear of the (7 tanks, 7 engines) core, and give enough thrust for positive liftoff, each booster has five Thud engines in addition to the Mainsail, giving this launcher a total of 43 engines (13 Mainsails and 30 Thuds) firing at liftoff. With the boosters pumping fuel into the seven core tanks, this launcher can circularize, even in polar orbit, with a restart of the booster core, leaving it on orbit with seven Poodle engines and enough fuel to run them for more than five minutes. By the previous standards of the KSP, Far Traveler is a monster -- but it gets the job done. Despite Jeb having done the testing of the lander and launcher, Val was selected for the first actual mission in this new vessel, because planetary missions are on temporary hold while the asteroid problem is evaluated. Asteroid are hers, for now. The selected target of her new mission was YMQ-666, which tracking showed was due to pass Kerbin within the Mun's orbit. Val was to attempt to get close enough to get a visual, and if possible rendezvous and return science data (ideally including a surface sample). Due to a miscommunication, she launched north, rather than south, but Mission Control recommended continuing the mission, so she burned to put herself into a synchronous orbit (same period as Kerbin's rotation, though not stationary), which after plane correction would cross the asteroid's path during its Kerbin encounter. Once her high parking orbit was established, Val made a large burn to completely reverse her orbit -- effectively, a 180 degree phase change, though at the apoapsis she had, the dV was hardly more than a Mun return. Once that was done, with the thought that she might actually be able to nudge the asteroid's orbit with her landing legs if she could park against it, she decoupled the lander and docked it back to the transfer stage, nose to nose, then deactivated the lander engines and flipped an all-important switch to reverse her controls, allowing her to fly by instruments with the same orientation she would have had in the command pod prior to decoupling. Then it was time to wait. After three orbits, plotting reported she had an intercept at a reasonable distance, and she made a burn to extend her orbit and correct her plane a fraction of a degree, then made two tiny correction burns (RCS only, with RCS shut off between burns to ensure it didn't cause drift) to give a final predicted intersect of only 2.1 km (albeit with 185+ m/s relative velocity). When she arrived at the intercept, however, there was nothing in sight. A rock estimated at half the length of the ship ought to have been visible, at least as a blinking dot, many kilometers away, but not only did she see nothing, the Tracking Station couldn't confirm a second object near her location. With the intercept passed (seemingly missed), and with nothing to show (even her science observations produced nothing new, since she was still in an orbit of Kerbin), she made a pretty small burn to lower her periapse into the upper atmosphere, and headed for home. On the first pass, she made a powered aerobrake with the transfer stage engines (testing a technique expected to be useful for future voyages), lowering her apoapse from 4000+ km to around 800 km in a single pass despite burning for less than a minute at 10% throttle, and without changing her periapse (selected at 55 km), thus demonstrating that repeated passes could be used if needed to control heating. On the next orbit (now just over an hour, compared to a full Kerbin day) she decoupled the transfer stage, still with 30% fuel, returned her controls to normal orientation, reactivated the lander's descent engines, and made a reentry burn test requested by mission control. Before burning out the lander's descent stage tanks (in conjunction with aerobraking above 50 km) she'd dropped more than 2 km/s velocity. She staged away the descent stage and found the ascent stage, now falling into somewhat thicker atmosphere around 40 km, was able to reduce velocity from just below orbital to about 1.3 km/s with use of only half its fuel. For the first time since the early orbital launches, she opened her parachutes without any loss of the ablation layers on her heat shield. Despite bringing back almost no data that R&D could use, she had learned things that Planning could turn into better future asteroid missions. One of these things, it was discovered, was that under circumstances yet to be fully defined, the plotting system at Mission Control could give a "ghost" position for an asteroid that had not yet entered Kerbin's sphere. In this case, it was found that, despite Tracking Center correctly showing asteroid YMQ-666 due for a Kerbin periapsis in 67 days, Mission Control's plotting system had shown it already beginning its encounter at the time of Val's launch. Technicians are on watch-and-watch until this problem is tracked down; in the meantime, priority is being give to another object, ASA-666, for which Tracking shows a Kerbin encounter due to begin thirteen days after Val's landing, and end thirteen days later -- but its Kerbin periapsis is zero, to the accuracy of available measurements. It appears this object may impact Kerbin. Fortunately, ASA-666 is tiny, what the astronomers are now calling Class A (the smallest current technology can detect in near-Kerbin space), with size comparable to a Munar Lander ascent stage and mass almost certainly less than the transfer stage and lander combined; it's very unlikely to do major damage, though it's uncertain what it might do if it strikes a population center. Val's next mission is to verify its size, if possible, and evaluate the possibility of deflecting it (or another object on a similar collision course).

One of the earliest German (WWII or slightly before) helicopter designs used compressed air jets to drive the rotor so it didn't produce reaction torque, and hence could fly without a tail rotor. The air was pressurized by an aircraft radial engine driving a big centrifugal pump. As noted, the Harrier uses reaction controls powered by air bled from the engine compressor; there was also a research variant of the F-104 Starfighter that had a cold gas (i.e compressed nitrogen, in that case) RCS system for use with a rocket motor that could kick the jet to well over 30 km altitude, where the jet engine and aero control surfaces were effectively dead weight. The Isp for RCS propellant is consistent with catalyzed hydrazine -- but I guess we'd have to have Real Fuels to be able to use hydrazine as fuel with an oxidizer like nitric acid, or use high test peroxide as monopropellant and also as an oxidizer. But then we'd have to allow for boil-off of liquid oxygen on interplanetary transfers, and liquid hydrogen for nukes even on a Minmus trip. Easier to just let liquid fuel be liquid fuel, and feed jets, nukes, and mix with generic oxidizer to work in bipropellant engines.