All Questions

12
votes
3answers
2k views

Could JWST stay at L2 “forever”?

Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST ...
3
votes
2answers
141 views

How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit?

The James Webb Space Telescope presents a huge reflective cross-section to the Sun's photons, and this can generate both torque and thrust. How will JWST manage solar pressure effects to maintain ...
9
votes
2answers
1k views

Supports in 3d printing

Do astronauts print 3D in space with supports? They are needed only because of gravity, which - on a space station - obviously is not a problem.
6
votes
1answer
139 views

Can we make super-massive Telescopes to image exoplanets?

This question has already been partly addressed here: When will we have the technology to directly observe an exoplanet with significant clarity? However, my question is focused more on the ...
3
votes
1answer
84 views

How many AGC keystrokes did an Apollo rendezvous take?

My kids have a rather nice picture book about the first moon landing titled “One Giant Leap”. I find it to be a fairly accurate retelling of the events of Apollo 11 in a poetic style. However, one ...
-5
votes
1answer
94 views

Can a reaction wheel decelerate to add momentum in the same direction? [closed]

Can a reaction wheel shed weight to gain speed? Could a reaction wheel at its max spin be flipped or rearranged around 180 degrees then slowed to add to its velocity?
2
votes
0answers
51 views

Have any ideas posted on this site been successfully implemented in a space exploration endeavor? [migrated]

Has any break through been made on Space.SE and incorporated? If so which question or answer was the most helpful?
5
votes
2answers
85 views

Determining GEO Orbital Slot from TLE

I'm trying to figure out the equation based on TLE data which orbital slot a GEO satellites occupies. I have the TLE data imported into R and I wish to know what satellites are in adjoining GEO ...
4
votes
1answer
117 views

Why was the image sensor design for Juno so… odd? [duplicate]

I attended the North Eastern Astronomy Forum this year and one of the speakers was mentioning that JunoCam will not be working because of the angle of the spacecraft. He was giving a lecture on what ...
1
vote
0answers
45 views

SpaceX Avionics [closed]

Just wondering what are some avionics aboard the falcon 9 and heavy. also what are some avionics on the dragon? Just general avionics that play a pivotal role in space travel.
5
votes
0answers
56 views

What is the difference between “Air-augmented rocket propulsion” and “integral rocket-ramjet propulsion”?

While going through the topic called "Combinations of Ducted Jet Engines and Rocket Engines" in Chapter 1 of Sutton & Biblarz's Rocket Propulsion Elements, 9th Ed I found the section below. Line ...
3
votes
2answers
173 views

Is the BFB/super heavy likely to have an easier time landing than the Falcon 9 booster?

Despite the deep throttle of the Merlin 1D engine, the weight of the Falcon 9 booster is less than the force of a single Merlin engine firing at minimum throttle (See here). This means that the Falcon ...
1
vote
2answers
93 views

Properly calculating G-factor

This may sound rather simple, but I was told that technically, G-force readout should actually indicate zero-G on the earth's surface, as well as in a stable orbit. This is due to the fact that G-...
1
vote
1answer
100 views

Can an Ion engine in tow assist in launch? [closed]

This question asks: How large a body could a probe with ion engines land on and launch from? and made me think could an ion engine that is the payload be mounted in a way to assist in the launch?
42
votes
3answers
8k views

What is GPS' 19 year rollover and does it present a cybersecurity issue?

The NPR new item and audio podcast The Global Positioning System Resets talks about a 19 year cycling of something in the GPS system, but it's not clear what it is. Every 19 years, the Global ...
3
votes
0answers
68 views

Just how record-setting was the launch-to-docking time of the April-4-2019 Progress resupply mission?

Digital Trend's article 3-plus-hour supply trip from Earth to International Space Station breaks record mentions that this was even faster than the typical "fast-track" Russian launch-to-docking time ...
1
vote
1answer
36 views

Resources for planning and schedule a launch-watching day-trip in Florida?

I know some busy people in Florida who I'd like to encourage to take a break and go watch a launch. They aren't "space people" and won't be keeping up on technical blogs or NASA or industry websites. ...
4
votes
2answers
170 views

What are these big shiny metallic “lumps” on the bottom edge of each Falcon Heavy nozzle?

What are these big shiny metallic "lumps" on the bottom edge of each nozzle of each core of this Falcon Heavy image from the Teslarati article SpaceX reveals Falcon Heavy Block 5 in first official ...
7
votes
1answer
2k views

What is the white spray-pattern residue inside these Falcon Heavy nozzles?

What is the white residue in a spray pattern seen on the inside of each nozzle of each side core of this Falcon Heavy image from the Teslarati article SpaceX reveals Falcon Heavy Block 5 in first ...
2
votes
1answer
69 views

What is the O/F mixture ratio and the ISP for the SuperDraco Engine by SpaceX?

Is it safe to assume a mixture ratio of 2.16 with an ISP of 313 s for the NTO/MMH, SuperDraco Engine manufactured by SpaceX? I am referencing the 2.16 propellant mixture ratio, and estimating or ...
9
votes
1answer
156 views

Why Orion can't be used to service JWST?

Hubble Space Telescope is a marvel of astronomical tools - particularly judging by how much it moved the science. It took a lot of fixes along the way, which certainly prolonged its useful life. Its ...
-1
votes
1answer
102 views

How to build a space catapult large enough to shoot a one hundered thousand ton spaceship in to low orbit?

I assume calculations start with the payload weight. A massive foundation would be needed lots of concrete and rebar meters thick. Also a harmonically sealed tunnel a thousand miles long filled with ...
0
votes
1answer
92 views

Will a spacecraft accelerate in a gravitational field via the use of a powered rotating mass?

I believe that a powered rotating mass on board a spacecraft should result in the spacecraft being propelled in a continuous increasing velocity towards the source of the gravitational field. To help ...
13
votes
1answer
1k views

Have astronauts in space suits ever taken selfies? If so, how?

Have astronauts in space suits ever taken selfies? Were selfie sticks used? If not, how was this feat accomplished?
0
votes
0answers
69 views

How many stages will be used to bring NASA astronauts to the Moon's south pole and safely back to Earth?

The question Has NASA “gone south”? Why are astronauts needed to explore the Moon's south pole? and its answers highlight the recent US executive branch's indeterminately-funded mandate. As far as I ...
3
votes
2answers
66 views

Speculation on the concept of in-space magnetic ring/rail launcher for a spaceship?

This is in reference to the question If human space travel is limited by the G force vulnerability, is there a way to counter G forces? Which, by my limited understanding, seems to point at the ...
1
vote
0answers
19 views

What Jovian system science targets would be suitable for Jupiter gravity assist flyby missions with other primary purposes?

Flying by Jupiter for gravity assist, and with the Oberth effect bonus, has been used for multiple missions to other outer planets and to comets. And has potential for use even for missions aiming at ...
1
vote
1answer
120 views

Is there any kind of research on *sub*-orbital rendezvous-ing with a space tug outside the atmosphere?

The key difference with a plain old-fashioned orbital rendezvous would seem to be that there'd be limited time to only briefly match velocities and trajectories: Let's say a vehicle launched from ...
1
vote
1answer
113 views

Can you really melt lunar regolith with microwaves?

This answer links to the 2008 Phys.org article with the catchy title NASA's dirty secret: Moon dust. The article says: Luckily, lunar dust is also susceptible to magnets. Tiny specks of metallic ...
3
votes
2answers
700 views

How thick does lunar regolith ever get? Has the thickness been measured and mapped by satellite?

Discussion in comments below the question Couldn't we just clear away the Moon Dust? have lead me to wonder if thickness of the lunar regolith is fairly well mapped by some combination of high ...
1
vote
1answer
55 views

What does the core stage of a launch vehicle mean?

I have seen the use of the term 'core stage' in the context of space launch vehicles. I am not able to clearly understand what it exactly means? I have learnt about launch vehicles having multiple ...
1
vote
0answers
25 views

How do Hayabusa-2's DCAM's work? (detachable cameras)

The screenshot below from the JAXAxxx video Mission Control Live: Hayabusa2 SCI Operation shows a diagram with DCAM3, a detachable camera that has the lucky job of watching the impact on Ryugu while ...
3
votes
0answers
56 views

Was Hayabusa-2's plastic explosive charge the largest charge detonated beyond LEO?

The BBC News article Hayabusa-2: Japanese probe set to 'bomb' an asteroid says: The charge is carried on the Small Carry-On Impactor (SCI) device. This is a 14kg conical container attached to ...
0
votes
0answers
41 views

How far will Hayabusa-2 back off before the “bomb” goes off?

The BBC News article Hayabusa-2: Japanese probe set to 'bomb' an asteroid says: The charge is carried on the Small Carry-On Impactor (SCI) device. This is a 14kg conical container attached to ...
3
votes
1answer
64 views

Puzzler: help understanding these amazing Curiosity eclipse GIFs

Starting from Curiosity Observes Sunset Eclipse: Sol 2358 I found three images in the sequence PIA23133, PIA23134, and PIA23135 which I thought would mean (but don't know for sure) that they are ...
2
votes
0answers
34 views

Why do the two Apollo 11 PSEP solar panels appear to have different backing materials?

The PSEP (Passive Seismic Experiment Package) was powered by a pair of solar panels mounted on extended arms. The one on the left (when looking towards the LEM) appears to have a matt grey backing: ...
-1
votes
1answer
162 views

Could this satellite wobble in orbit creating additional orbital angular momentum?

This question asks if this type of steam engine would work: Could a steam Engine outperform other electric producing devices in space? this not a sterling engine since it has far less moving parts. ...
14
votes
5answers
3k views

Why does Arabsat 6A need a Falcon Heavy to launch

Is it just me or does a falcon heavy seem like a bit of an overkill to launch Arabsat 6A? Falcon Heavy - GEO payload: 26,700 kilograms Arabsat 6A - weight: ~6000 kilograms Wouldn't some other ...
5
votes
1answer
49 views

Are there any references about rocket Launchapd Design?

I am trying to figure out all the systems/structures/services that would be required to support rocket launches. Are there any references that describe this information? Essentially, I want to have ...
9
votes
1answer
303 views

Couldn't we just clear away the Moon Dust?

I read that "Moon Dust" is ranked by NASA as the number one challenge to building a permanent lunar base. Wouldn't it be possible, though, to send some type of lunar excavators to clear a large zone ...
5
votes
0answers
64 views

Would a terraformed Martian athmosphere even persist? [duplicate]

So I saw a question here mentioning that omnipresent idea of terraforming mars by somehow giving it more atmosphere (here it was melting/evaporating the polar ice caps). My problem with that is: ...
4
votes
1answer
72 views

Why do GEO satellites need different types of antenna?

Why do GEO satellites like the one shown in the picture below need different types of antenna? Is there a reference library or website where we can get more information on different antenna types, ...
12
votes
2answers
3k views

Can a rocket refuel on Mars from water?

Can a rocket run only on hydrogen and oxygen? Could a rocket, rover, and electrolysis machine be sent to either of Mars' poles to excavate ice to make hydrogen and oxygen to refuel an unmanned rocket? ...
2
votes
1answer
72 views

How to find an optimal number of propellent tanks?

My idea: If the propellent mass to tank mass ratio remains constant when increasing/decreasing the amount of propellant then you could increase $\sum \Delta v$, by splitting the propellent tank and ...
3
votes
2answers
78 views

Most preferred coordinate system for Launch vehicle trajectory

To integrate the equations of motion for a launch vehicle trajectory to the orbit, which is the best coordinate system to consider of the following two: Rectangular with Earth-centered inertial frame ...
2
votes
1answer
55 views

What is the nozzle extension of merlin engine and rutherford engine made of?

It is clear from the pictures, that the nozzle extension of Merlin and Rutherford vacuum engine aren't actively cooled. What is the material of construction for those nozzle extension to withstand ...
2
votes
0answers
64 views

How were Parker's sapphire elbows made?

The YouTube video The AMAZING Design of the Parker Solar Probe - Smarter Every Day 198 is quite interesting, as is the video Destin's second "Smarter" channel's video Scientist Interview: Dr. Tony ...
1
vote
2answers
107 views

Why would rocket bodies use specifically ablative coatings to reduce boil-off of cryogenic propellants? Is ablation important for this?

The end of YouTube video Delta IV Heavy Pad Tour, (with CEO Tory Bruno) - Smarter Every Day 199 points to Destin's second "Smarter" channel's video UP CLOSE Delta IV Heavy Launch Pad Tour (Tory Bruno ...
8
votes
2answers
157 views

How do astronauts maintain their neck muscles?

The human head weighs 5kg. This weight keeps the neck toned and strong. In zero gravity on extended missions how do astronauts maintain muscle and bone strength in their necks? What type of neck ...
6
votes
0answers
187 views
+200

What was Sutton talking about? How to “obtain small accelerations by taking advantage of difference in gravity as a function of altitude”?

Sutton and Biblarz's Rocket Propulsion elements says in Chapter 1, section 1.2 (editions 7, 8, 9, possibly earlier as well) that: Totally different methods of producing thrust are used in ...

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