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3

I believe I might have found an answer to this question in this interesting paper, which reviews the origin of duration and distance requirements for planetary mobility systems. It appears the 90 sol value could tie its origin to the early studies for the Mars Exploration Rovers - Spirit and Opportunity. According to the paper, at the time of MER's early ...


3

SunRISE will deploy a constellation of cubesat spacecraft which together will synthesize a radio-frequency antenna large enough to give the angular resolution required to study the solar phenomena of interest. They will need to move those individual spacecraft around from time to time to optimize the geometry for aperture synthesis. If they were at ...


1

Partial answer: Why "slightly above" rather than at? Why not slightly below? not directly related to SunRISE but https://ntrs.nasa.gov/api/citations/20130000278/downloads/20130000278.pdf had this to say regarding design end of mission passivation/moving to graveyard orbit: The altitude is generally increased, as opposed to decreasing, to prevent ...


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Caveat: Most of my knowledge of such things comes from "word of mouth" discussions with my senior colleagues and their experiences with how things have changed in regards to funding and costs. So take that into account when reading the following. Several years before I was hired (I was hired in September 2010), my boss was asked to draft up a ...


2

In 2007 it was decided to add a docking ring to JWST. (1) This was not for any particular servicing capability. Rather the idea was: who knows what capabilities may exist in the future. (The instruments are not designed to be serviced or replaced). In 2004, NASA began a study of a possible robotic servicing mission for the Hubble. (2, 3). The result of ...


2

The question is very broad covering everything from failure to launch to a stuck part requiring a gentle nudge. Someone can address all the engineering solutions to particular problems, but I'm going to address the hard reality that... Failure is always an option. Any exciting space rescue has to be cheaper, simpler, and less risky than just building a new ...


1

Too big for a comment; however not a complete answer. The following cases are all LoV scenarios no matter the cost or complexity: Launch phase (to LEO) Loss. Launch phase (boost to Halo orbit) Likely total loss given that the upper stage makes only one burn. A failure of the upper stage engine will probably not leave the spacecraft in a serviceable orbit....


4

(Partial answer, as a complete answer would include the nominal mission timeline.) The unfolding of the sunshield is scheduled to start on the third day of the mission. From this page: Forward Sunshield Pallet This step begins the Sunshield deployment phase. Nominal Event Time: Launch + 3 days The deployments team begins planning and operations to deploy ...


5

@asdfex comment is correct. It was explained during the live broadcast by Daniel de Chambure, who was in charge of the modifications made to Ariane 5 to accommodate the JWST. Basically, they want to keep certain parts of the telescope away from the sun at all time, so a complete roll is not allowed. Hence, they're rolling back and forth to avoid overexposure ...


1

There was never any chance of conjunction! The launch happened at "lunch time" in western Europe, at about 12:20 UTC on 25-Dec-2021. Santa would be in places where it was late at night or early morning, when all good little astronauts would be asleep, so say 24-Dec-2021 22:00 to 25-Dec-2021 04:00 local time to avoid dawn or getting too far behind ...


1

By the time JWST launched, Santa should have been long since done with his errands in that part of the world. And JWST was way above Santa's track PDQ!


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//Partial Answer as advised// Chemical Thrust Transfer This section is my answer to the first part of my task. I believe this is correct. My only worry is that is might not qualify as "Hohmann-like", mostly because it seems like a vague specification and I am not sure about the difference between Hohmann and Hohmann-like. Chemical Maneuver ...


3

In theory, there is no upper limit to the maximum force a spacecraft could experience in deep-space. In practice, spacecraft design to orbit other planets will experience a large force during the orbit insertion manoeuvre. As an example, the Mars Reconnaissance Orbiter (MRO) used 6x 170 N engines for Mars Orbit Insertion (MOI), which would provided a ...


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