Questions tagged [mission-design]

Mission design is the process of designing a space mission to fulfill a particular objective.

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7 answers
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Is there something inherently more difficult about servicing satellites in the 2nd Sun-Earth Lagrangian point?

There are several questions already asked on here about the potential for servicing the James Webb Space Telescope. This question asks what happens if the JWST needs repair. Basically, there are no ...
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1 vote
0 answers
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Installation procedure for NASA's Evolutionary Mission Trajectory Generator (EMTG)?

I am doing trajectory optimization, and want to use NASA's Evolutionary Mission Trajectory Generator (EMTG) software to investigate dates for various trajectories. However, this software does not come ...
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0 answers
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Non-coplanar transfer in GMAT

I am trying to use GMAT to do a non-coplanar transfer between 2 circular orbits. In which the first orbit would have a 0º inclination, and the final orbit would have a 28º inclination. And the ...
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2 votes
1 answer
31 views

GMAT: What causes the error "ArrayTemplate error : dimension error"?

I have made various scripts that work with GMAT, but once in a while I get an "ArrayTemplate error : dimension error" error. I do not know what causes it, as in this case my script appears ...
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1 vote
0 answers
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NASA GMAT Hardware in the Loop testing

We are currently evaluating various Mission Analysis & Simulation tools, one of which is NASA's GMAT (2020). One of our requirements is for the tool to support HITL testing. However, i am unable ...
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1 vote
0 answers
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More advanced alternatives to Trajectory Optimization Tool?

I've been using Arrowstar's Trajectory Optimization Tool to plan interplanetary transfers, and it works well. The next thing I want to do is plan gravity assists from the Sun-Earth L2 Lagrange point ...
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1 vote
0 answers
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Solar Sail mission

Sorry for my English. I'm not native speaker I would like your advice in solar sail mission simulation. The purpose is to compare results with results in Wolfram Mathematica. We have CubeSat with ...
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8 votes
1 answer
901 views

Can double deck spacecraft be designed and constructed for manned missions?

Double Deck Aeroplane Similar to double deck Aeroplane, can a double deck crewed mission spacecraft be designed and constructed? Benefits: More astronauts in the manned mission spacecraft viz Mars, ...
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1 vote
1 answer
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What is "trade space" in the context of libration orbit mission design? (used in trade analysis, launch window analysis and trade study)

The introduction to Launch Window Trade Analysis for the James Webb Space Telescope reads: The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental ...
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1 vote
0 answers
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How do I construct halo orbits around the Sun-Earth L2 point in GMAT? What should the state vector of the spacecraft be?

I am new to trajectory design, and have been using GMAT to learn it since it's free, unlike STK. I have been trying to design a script that takes a spacecraft from Earth orbit to a halo orbit around ...
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5 votes
2 answers
133 views

Where is the Wind going? Where has it been? (Global Geospace Science spacecraft 1994-071A)

This excellent answer to Why put DSCOVR in a Lissajous orbit? Wouldn't a halo orbit completely avoid the Sun exclusion zone? explains that the Global Geospace Science or Wind spacecraft ...
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13 votes
2 answers
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Which 3D space simulation/visualization software (free or commercial) can I use as a post processor of data calculated with Fortran?

I'm designing a space interplanetary mission (Design of low-energy trajectories to Near Earth Objects) by using Fortran. Basically I'm working with the Circular Restricted 3 Body Problem (CR3BP), ...
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0 votes
1 answer
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Why does Q-SAT look like a buckyball?

Tech.China.Com.cn's August 7, 2020 article Tsinghua University Successfully Launched Gravity and Atmospheric Science Satellite (Chinese, title translated to English) includes the image above of what I ...
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2 votes
0 answers
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NASA GMAT: Any good tutorials or methods to learn how to use patch points and control points to come up with viable and optimal trajectories?

I'm a beginner to trajectory design, and have to use NASA's GMAT software. It's been a few weeks now, and I have done the first four tutorials and managed to create a (very unrealistic and sub-optimal)...
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3 votes
0 answers
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How is the moon's orbital motion accounted for in determining the best observation platform/location for JWST at L2?

The moon's periodic motion would appear to impose a perturbation to the otherwise equilibrium state of the solar/earth L2 point.
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2 votes
1 answer
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For JWST's "29.5 days of terror" before orbital insertion, unfolding the sunshield is the scariest for me. When is this scheduled to happen?

At what date and time UTC is JWST's unfolding of its sunshield scheduled to begin? At what date and time UTC is confirmation of success expected if all goes smoothly?
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3 votes
0 answers
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How the number of Sun sensors is chosen for a given spacecraft and mission?

I have to study an ADCS sensors suite and I am struggling to find a criteria to decide how many and in which directions the sun sensors shall be mounted, considering that they are coupled with star ...
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1 vote
2 answers
118 views

Closest approach between the JWST launch vehicle and Santa Claus's sleigh?

This ABC News video describes how for the 66th year in a row NORAD will be tracking Santa Claus's progress. This year they will have to contend with a potential conjunction between Santa's sleigh and ...
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0 votes
3 answers
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How would a repair of the JWST proceed if it were ordered regardless of the cost and technical hurdles, depending on when/how it fails? [closed]

I have heard people speaking about how, unlike Hubble, the James Webb Space Telescope is "one of a kind", "not designed to be repaired", "not serviceable", and the like, ...
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2 votes
1 answer
101 views

"Hohmann-Like" and Chemical / Electric Thrust Comparison

Part of the work I have to do for my degree is to perform a "Hohmann-like" transfer between Earth and Mercury, of which I believe I have accomplished. I have attempted numerous times to ...
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4 votes
1 answer
234 views

Why does JWST need "a carefully designed series of oscillations" to avoid overheating during the 2nd stage burn? Why not rotate "rotisserie style"?

The Northrop Grumman video James Webb Space Telescope Launch and Deployment describes the trajectory from launch to orbital insertion and illustrates several key maneuvers and incremental steps in the ...
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4 votes
1 answer
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Why is 90 sols a standard mission duration for robotic spacecraft on the surface of Mars?

Several robotic Mars surface missions have a planned mission duration of 90 sols. I would like to understand why this specific mission lifetime is commonly used by mission planners. Below is a non-...
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40 votes
2 answers
5k views

Why doesn't JWST use ion thrusters?

Since the L2 point is unstable, JWST needs engines to maintain its orbit. It uses mono-propellant engines which have given it a 5-year minimum lifespan. Why weren't ion engines used instead? Wouldn't ...
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4 votes
0 answers
117 views

How much more does it cost to produce two identically designed probes/rovers/satellites compared to making only one?

There are a number of historical planetary missions that have produced 2 flying instances. Examples include Voyager, Viking, MERS, some of the Mariners missions. Other missions have only one ...
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3 votes
1 answer
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Why did the last six TDRS satellites start at ~7° inclination on a downward trend that appears to be "repelled" by zero & bounce back w/o crossing?

The most recent six TDRS satellites (8 through 13) were inserted into moderate inclination orbits of roughly 7°, and in all cases their inclinations immediately decreased at rates of about +/-1 or +/-...
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7 votes
4 answers
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Has ion propulsion ever been used in a deep space trajectory correction maneuver proper?

Answer(s) to What types of propulsion are used to adjust an orbit? lead me to wonder if electric propulsion has ever been used for a proper TCM or "trajectory correction maneuver" in deep ...
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26 votes
3 answers
5k views

How will DART be able to hit a 170 meter rock dead-center at over 6000 m/s? What technologies will be use and how will they work together?

The DART spacecraft will ultimately be a kinetic energy impactor, using its 500 kg mass at a relative velocity of over 6000 m/s to slightly change its target 65803 Didymos's companion Dimorphos's ...
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1 vote
1 answer
261 views

Deep space marksmanship; will DART's intercept and impact trajectory represent the best ever if successful? If so, by how much?

The DART spacecraft will ultimately be a kinetic energy impactor, using its 500 kg mass at a relative velocity of over 6000 m/s to slightly change its target 65803 Didymos's companion Dimorphos's ...
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1 vote
1 answer
179 views

How does a 22 dBi X-band "patch" antenna get so much gain and how well behaved is its high-gain radiation pattern?

@NgPh's answer to How will the LICIACube cubesat transmit DART impact images back to Earth? What kind of antenna and radio will it use? quotes LICIACube on DART mission: an asteroid impact captured by ...
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0 votes
1 answer
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Are any space agencies working on an (essentially) 100% reliable sterilization technique for spacecraft bound for subsurface ocean worlds?

One answer to my previous question Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional? asserts: ...
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5 votes
0 answers
135 views

Could the International Space Station (ISS) be refurbished to save money?

I was reading an old article about deorbiting ISS (Death Star: The ISS Doesn’t Have a Way to Crash Safely) and wondering if we could refurbish ISS instead of deorbiting it? I thought deorbiting it ...
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0 votes
0 answers
32 views

How to use the Util and Base Code of the General Mission Analysis Tool

GMAT (General Mission Analysis Tool) provides detailed Util and Base Code, but I don't know how to use it, namely I still don't know how to access so many data of some missions. Can somebody provide ...
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1 vote
1 answer
109 views

How exactly did Cassini provide rock-solid attitude control to enable high resolution low light imaging? (1.2 arcsec/pixel for narrow angle camera)

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. At about 45:45 it discusses the period after SOI (Saturn Orbit ...
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1 vote
0 answers
90 views

Which deep-space spacecraft flew closest by Earth during a gravitational assist?

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. (Don't forget Part II as well!) At about 26:30 it discusses ...
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5 votes
0 answers
186 views

When was Lucy's mission first scripted in Excel and why is that what Lockheed Martin chose to do it with?

CNBC's NASA spacecraft launches toward Jupiter asteroids on an intricate path charted by Excel Years before Lucy took off, Lockheed Martin mission architect Brian Sutter used Excel to chart the ...
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6 votes
4 answers
233 views

Why put SunRISE in the graveyard? Why will it "fly slightly above geosynchronous orbit"?

The blots.nasa.gov article NASA’s SunRISE Mission Studying Solar Particle Storms Moves Toward Launch says that the upcoming SunRISE mission — short for the Sun Radio Interferometer Space Experiment — ...
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4 votes
1 answer
141 views

Just how preferable are afternoons for flying Ingenuity? Why?

JPL tweet links to mars.nasa.gov's Flying on Mars Is Getting Harder and Harder which explains that seasonal changes are lowering the density of the local atmosphere, presumably due to warmer seasonal ...
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0 votes
1 answer
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How do Spaceship navigate in space?

In Space there is no air to put thrust on any other thing to expect any action-reaction forces. Then how do spacecraft go left or right or are the ineligible to take sharp moves?
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5 votes
1 answer
256 views

What factors would contribute to a spacecraft's ability to maintain a very low orbit (VLEO) or at least orbits with very low perigees?

I asked What does account for a high coffin corner of a plane? in Aviation SE. Now I wonder what factors would contribute to a spacecraft being able to maintain low circular orbits (e.g. within 200 km ...
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4 votes
0 answers
89 views

Why are the four launch opportunities within each Inspiration4 launch window "about an hour apart"?

In the SpaceX Inspiration4 Launch broadcast at about T-01:31:05 (91 minutes before launch) the process for selection of launch windows for the mission is roughly ...
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3 votes
0 answers
106 views

Design and optimization of a Sun-synchronous repeating ground track orbit constellation

I am currently researching about this topic and am very new to this. Have no clue how to go about designing a group of imaging satellites (constellation) that are sun synchronous with repeating ground ...
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-2 votes
1 answer
122 views

Space settlement in Jupiter [closed]

Would a space settlement located in one of the orbits of Jupiter be economically feasible? According to me, it would be quite profitable in the long run, as 1) The settlement can act as a pit stop for ...
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0 votes
1 answer
78 views

How did Japan’s Hayabusa 2 mission "make extensive use of deployable cameras to get scientific imagery"? Did it ever produce a "PR selfie"?

Scott Manley's recent video China's Mars Rover Zhurong Has Completed Its Primary Mission, Reaches New Milestone includes the following: And if you thought that dropping a camera on the surface of ...
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2 votes
1 answer
105 views

After CAPSTONE inserted to "highly efficient ballistic lunar transfer trajectory" by Lunar Photon; to what separate orbit for its safe disposal? How?

NASA Ames's feature CAPSTONE’s CubeSat Prepares for Lunar Flight says CAPSTONE will use a hydrazine-fueled propulsion system during most of its three- to four- month journey to the Moon. This line of ...
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6 votes
1 answer
189 views

Is there a fairly detailed outline of CAPSTONE's "highly efficient ballistic lunar transfer trajectory" from LEO to lunar near-rectilinear halo orbit?

NASA Ames's feature CAPSTONE’s CubeSat Prepares for Lunar Flight says CAPSTONE will use a hydrazine-fueled propulsion system during most of its three- to four- month journey to the Moon. This line of ...
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18 votes
5 answers
5k views

Exactly why does Starship need to be this big for interplanetary travel?

As discussed in several answers to Isn't Starship way too big? Starship's unusual size is due to it being intended for missions to the Red Planet. But why? Even a smaller ship could satisfy the ...
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2 votes
0 answers
72 views

what kind of valves are used in payload fairing for venting?

I wanted to know that there have been a handful of literature that mentions vent openings in the rocket payload fairings. However, none specify the kind of valves used in those fairings? does anyone ...
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0 votes
2 answers
162 views

Can we land on an asteroid and ride on it?

If we could land on an asteroid, not necessarily a human, we would save the fuel consumed for flying the spacecraft and we will benefit by having the systems on it running for a very long time.. If ...
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3 votes
0 answers
134 views

Most dog-legged launch?

There are enough questions about dogleg maneuvers that there is now a dogleg tag, but the definitive dogleg answer is @JakeBlockers (linked below) which includes images of a dogleg from Florida that ...
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1 vote
0 answers
25 views

Closest distance that two unrelated spacecraft have come while both in heliocentric orbits?

In 2015 STEREO A and B passed each other passing roughly behind the Sun at the same time from opposite directions as seen from Earth. But these two are part of a single mission, put into these orbits ...
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