25

Ulysses, the shuttle-launched joint NASA/ESA probe to study the sun's polar regions, ran through three comet tails, more or less by chance. Ulysses Catches Record for Catching Comets by Their Tails ...comet Hyakutake ...On May 1, 1996, while Ulysses was cruising through space studying the solar wind, its data suddenly went wild for a few hours. The once-...


20

Your intuition is quite correct. The Hohmann transfer orbit is a bi-tangential orbit, so at the point where the spacecraft leaves Earth, it is travelling in parallel to us. In the case of Mars, we want to travel slightly faster than the Earth in order to lift our aphelion up to the orbit of Mars, meaning we want a little extra velocity on top of the prograde ...


14

Rosetta collected dust from 67P/Churyumov-Gerasimenko and analyzed it under an atomic force microscope, without landing on the cometary body itself; depending on your definitions this would seem to imply having flown through its tail. Navigation isn't much of an issue; you simply navigate close to the cometary body and hang out on the sunny side -- though I ...


12

According to NASA's history on the mission, Pioneer 11's goals included both investigation of the solar wind outside of the ecliptic, and a look at the polar regions of Jupiter, which appeared to have a more transparent atmosphere than the equatorial regions. A close flyby of Jupiter over either pole would unavoidably sling the spacecraft out of the ecliptic,...


12

The two Vega probes comes to mind, ending their implausible sounding mission of slipping balloons into the atmosphere of Venus with a flyby of Halley's comet in 1986. They took a heavy beating flying through the coma, which is the shell of dust and gasses surrounding the comet itself, at the start of the tail. From a navigational point of view, the goal ...


11

What was the duration of the launch window this day? According to Spacelaunchnow, the daily launch window was instantaneous, but there were daily opportunities from July 15 to August 12. Did it first enter a short period of LEO for phasing and/or staging, or did it launch directly into its interplanetary trajectory? From the timeline, it appears that it ...


10

The International Cometary Explorer spacecraft passed through the plasma tail of 21P/Giacobini–Zinner in September, 1985, which I think was the first time the human race had engineered such a rendezvous. Many years ago, in my salad days, I did my PhD research on the encounter.


9

Only one burn, just before landing, according to Blue Origin's broadcast of NS-12's flight. The only events during climb relating to engines are liftoff and MECO (main engine cut off). After apogee, 45:00 in the video, T+4:45, the only events at all are wedge fins deploy, drag brake deploy, booster restart, and booster touchdown. (Here are photos and ...


8

The Falcon 9 first stage is making three burns wile descending: Nope. It is making two burns while descending. boostback burn This burn happens while the rocket is still ascending. This burn only happens for return-to-launch-site landings. For ASDS landings, it doesn't need to "boost back", because it isn't going back, it is going forward. (They ...


8

It's using the gravity of Venus alone. Skimming the atmosphere would risk damaging the spacecraft From the NASA blog On Oct. 3, Parker Solar Probe successfully completed its flyby of Venus at a distance of about 1,500 miles during the first Venus gravity assist of the mission. These gravity assists will help the spacecraft tighten its orbit closer and ...


5

The telescope was placed into a heliocentric orbit when its helium supply was depleted On 29 April 2013, ESA announced that Herschel's supply of liquid helium, used to cool the instruments and detectors on board, had been depleted, thus ending its mission. At the time of the announcement, Herschel was approximately 1.5 million km from Earth. Because ...


4

During an interview with "the Angry Astronaut", Dynetics HLS Payload Manager Kathy Laurini suggested that the drop tanks could be salvaged and incorporated into a fuel tank farm. This suggests the tanks are dropped at a very low altitude just before touchdown, otherwise the impact would destroy them.


4

I cannot give you a valid answer for later Missions, but here something about Pioneer and Voyager: As Scientists discover there is a very rare planet constellation in the 70/80ies allowing to pass all large outer planets with one mission, they had been very keen in doing this mission (Voyager). BUT: In fact they have not known if it is possible to cross the ...


4

@Machavity's answer is correct. This is just some addition, interesting data. I had downloaded the data for Parker Solar Probe from Horizons before the launch. They had state vectors for a complete (planned) mission there (Revised: Aug 24, 2018) from launch until 2025-Aug-31 09:19:00. Currently Horizons is showing a much shorter span because it is now based ...


3

Is it possible to combine both approaches to perform flybys to the outer planets and escape the solar system?? Launch it first as if it was a Venus mission which heavily relies on oberth trickery, then use Venus and Earth gravity assists to reach Jupiter, and from there beyond Basically yes. If your main concern is to get to the outer solar system or onto a ...


3

Ideally, trajectory correction maneuvers would never be needed. Ideally, the spacecraft's position/velocity state before and after then coarse maneuver would be known perfectly and instantaneously, and the accumulated delta V applied by the spacecraft would be perfectly applied and perfectly measured. Nearly ideally, the ideal time to perform a trajectory ...


2

The problem with such tools is that they may be considered a national security risk as the principles are similar to those of missiles. However, there are excellent Master theses and PhD dissertations on the topic of optimal control for landing rockets, such as this MSc thesis and this SpaceX paper. These will explain the equations of motion and part of the ...


1

In 1986, Giotto closely approached Halley's comet flying through dust and gas and surviving with less damage than expected. I couldn't tell if Giotto was flying through Halley's tail or coma, but its journey can be taken as an upper bound of how harsh flying through the tail can get.


1

Apollo 11 first entered a 103 nautical mile orbit, and midway through orbit 2 was boosted onto lunar trajectory. This was 2hrs 50mins into the mission, so from this point onwards, mission control were not considering orbits of the Earth. Apollo 11 passed 22k nautical miles at 5hrs and 22 minutes into the mission. 2:54 p.m.- The spacecraft is reported 22,...


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