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Couldn't really find this topic of discussion, it may be better served as part of the Vs board, but it's a purely Star Wars question:

How fast can ships in Star Wars go without engaging their Hypderdrives?

I can think of a few instances from which a calculation might be worked out, but as far as I am aware it hasn't been covered yet.

Those instances being:

From the original film, Battle of Yavin, the X-Wings takeoff to reach the Death Star, I seem to recall it approaching the speed of light or exceeding it to get to the Death Star as fast as they did -- and then they accelerated to attack speed.

From The Empire Strikes Back -- The Millennium Falcon getting to a different system "nearby" without Hyperdrive. I'm sure there's a way to calculate "Average distance between stars" with an assumption on how long it took.

From The Clone Wars "Jedi Crash" - the titular crash has them going relativistic speeds, but that was out of control.

Most of these instances involve smaller craft, but I'm sure there's things in the books about how long it takes for a ship to make it from one part of a system to another.

I couldn't find anything on this after a brief search (could have put in bad parameters), so I was wondering if anyone else knew more.

Canonically, the Falcon had a short-range low-speed backup hyperdrive for the jump to Bespin (although one wonders why they did not use it to escape during the chase).

Goodly fractions of c (~1-10%) - several thousand kilometers per second - are entirely reasonable estimates considering that the Falcon made it to the asteroid field of Hoth system in a timeframe of minutes to hours (~1 light minute in 1 hour = 1.6% c), and X-wings made it across the Yavin moon system within 10-15 minutes. Assuming an orbital radius in the ~half-million-kilometer range (and a distance of a million kilometers, that's at least a thousand kilometers per second (0.3%c).

The thing is that with hyperdrive, there's no point building an engine for high-c travel. Since hyperspace recursion points are found in distant orbits around virtually all planets (we see ships come out of hyperspace in medium orbit all the time) rather than limited to a few per star, there really is not much of a point going beyond 0.1c - 30,000 kilometers per second will get you beyond lunar orbit in twelve seconds flat - enough for fast-paced war (on, out of universe, one scene). 0.01c - 3,000 km/s - gets you to the moon in two minutes - also quite adequate for the casual traveller. I lean towards the lower end of <0.05c.

As usual, there are no maximum realspace speeds other than light, so... depending on your exhaust velocity and with infinite power from hypermatter reactors, you could get pretty close to that (chucking a relativistic particle beam in the exhaust might fry planets, though). Ship descriptions in Incredible Cross-Sections have maximum accelerations in the thousand-gee range (so one second to get up to 10km/s and two minutes to get to 1,000 km/s), which I find eminently reasonable.

Also, we never see relativistic time dilation effects or people talking about relativity, so I would guess that nobody ever feels the need to go beyond 0.3c or so (again, why not use hyperdrive?), which is where you start getting time dilation factors of >5% - that is, noticeable time dilation factors. Time dilation at 0.1c is a minuscule 0.5% - people will totally ignore it unless they need really precise timekeeping or something (that hop up and down to orbit takes under ten minutes, so your watch will be off the "galactic standardized non-relativistic hyperdrive-clock-linked holonet timebase" by no more than a few seconds).

http://www.projectrho.com/public_html/r ... light3.php

While I agree with you, there is one mention of time dilation I can recall - in the ROTS ICS book, the section on the Jedi fighters and their hyperdrive rings includes a line about the rings having stasis generators, so that the pilot ages as slowly as the rest of the galaxy. That may mean there's some weird hyperspace effect going on, but that's at least one mention I can recall.

Eternal_Freedom wrote: ↑2020-05-30 08:39am While I agree with you, there is one mention of time dilation I can recall - in the ROTS ICS book, the section on the Jedi fighters and their hyperdrive rings includes a line about the rings having stasis generators, so that the pilot ages as slowly as the rest of the galaxy. That may mean there's some weird hyperspace effect going on, but that's at least one mention I can recall.

Good to know, thanks. I was a stingy child, and missed my chance to own a copy of ROTS ICS . Read it in the bookstore over and over and over, but never got the guts to buy it with carefully hoarded dollars and quotas (I have Ep II and OT).

It is a weird effect - if anything, you'd expect backwards time travel at FTL speeds (hence causality breaking if there is no nonrelativistic galactic timebase).

Isn't this question mostly determined by how long they want to burn for and how well their hull/shields are rated against likely impactors? If you wanted to slow boat your way to another star or just the outskirts of your system's Oort cloud there's not much stopping you, but it doesn't seem like something your average Star Wars character would want or need to do.

Pre-Disney.

In the 'New Jedi Order' series, it mentioned Starfighters accelerating to near lightspeed to move between engagements within a star system. I believe that was during the GFFA reconquering Coruscant.

chimericoncogene wrote: ↑2020-05-30 01:55am Canonically, the Falcon had a short-range low-speed backup hyperdrive for the jump to Bespin (although one wonders why they did not use it to escape during the chase).

Easy explanation. Backup hyperdrives take a while to align and set up/spool up. It's an EMERGENCY hyperdrive, so nobody cares if it takes 6 hours to spool up for a jump.

A smuggler on the other hand wants his main hyperdrive to be ready in about 15~ seconds or less.

MKSheppard wrote: ↑2020-05-31 09:15am

chimericoncogene wrote: ↑2020-05-30 01:55am Canonically, the Falcon had a short-range low-speed backup hyperdrive for the jump to Bespin (although one wonders why they did not use it to escape during the chase).

Easy explanation. Backup hyperdrives take a while to align and set up/spool up. It's an EMERGENCY hyperdrive, so nobody cares if it takes 6 hours to spool up for a jump.

A smuggler on the other hand wants his main hyperdrive to be ready in about 15~ seconds or less.

Yeah it's essentially a hyperdrive equilevant of a spare tire, fine if you have to get somewhere to get the main drive fixed but it's not meant to replace the main drive, but rather be just good enough that you won't get stuck centuries from civilization. So it really just need to get to a space dock to repair so it doesn't matter if it breaks the moment you get to the spacedock you're there so the emergency drive worked.

There's also the possibility that you don't keep your emegency backup hyperdrive fueled (or the Falcon doesn't), and it took time to fuel it up.

Solauren wrote: ↑2020-05-31 10:51am There's also the possibility that you don't keep your emegency backup hyperdrive fueled (or the Falcon doesn't), and it took time to fuel it up.

Yeah the same way you don't keep your spare tire pre-installed, that's why I think the analog of a "spare tire" is good for the back up hyperdrive, it's something that's there if you really need it but it won't be convinient to use and it can't be used as a true replacement only as a emergency back up to get you to a place where you can get repaired. That probably why Han said "Bespin is pretty far but I think we can make it" he knew the back up drive could fail at any moment if pushed too far but was confident that Bespin wasn't too far for it.

Lord Revan wrote: ↑2020-05-31 11:25amYeah the same way you don't keep your spare tire pre-installed, that's why I think the analog of a "spare tire" is good for the back up hyperdrive, it's something that's there if you really need it but it won't be convinient to use and it can't be used as a true replacement only as a emergency back up to get you to a place where you can get repaired. That probably why Han said "Bespin is pretty far but I think we can make it" he knew the back up drive could fail at any moment if pushed too far but was confident that Bespin wasn't too far for it.

Could be that spare hyperdrives are only rated for so many "Starts" and "hyperspace hours". A regular hyperdrive might last for say 500 starts and 10,000 hours before requiring overhaul; while the spare is only good for say 5 starts and 100 hours?

That could put another kink into Han's logistical planning -- he has to find a relatively quiet spaceport within the limits of the drive, because the Falcon is extremely "hot" since Vader wants it.

MKSheppard wrote: ↑2020-05-31 09:15am
Easy explanation. Backup hyperdrives take a while to align and set up/spool up. It's an EMERGENCY hyperdrive, so nobody cares if it takes 6 hours to spool up for a jump.

A smuggler on the other hand wants his main hyperdrive to be ready in about 15~ seconds or less.

Well, they had an hour (less?) in the big space worm, but yeah, I never thought of that. Thanks.

chimericoncogene wrote: ↑2020-05-31 01:03pmWell, they had an hour (less?) in the big space worm, but yeah, I never thought of that. Thanks.

They also thought that the big space worm was a cave they could stay put in until the problem was solved, and that the main hyperdrive was repairable with on-board resources. Given that Han tried the main drive to escape from the Avenger they'd probably completed repairs but hadn't gone through any preliminary testing. Once that failed they hooked up the backup and jumped to Bespin (i.e. the closest system with decent repair facilities willing to turn a blind eye to a wanted ship) rather than spending an unknown period hanging around in open space trying to figure out what had gone wrong this time.

Spare tire idea makes a lot of sense if you also recall that many spare tires warn you not to go over a certain speed when driving on them. Exceeding that speed could cause another breakdown (which is why I was going 40mph on the interstate with my 4-ways on; the donut spare couldn't go faster safely)

LadyTevar wrote: ↑2020-06-01 11:06pm Spare tire idea makes a lot of sense if you also recall that many spare tires warn you not to go over a certain speed when driving on them. Exceeding that speed could cause another breakdown (which is why I was going 40mph on the interstate with my 4-ways on; the donut spare couldn't go faster safely)

IIRC spare tires are built weaker then regular tires to save on cost, after all if you're lucky you'll never have to use a spare tire (doubtful it'll ever happen but not impossible). So a spare tire wouldn't have to withstand the same amount of wear and tear as a regular tire, since you're suppose to use just long enough to get the broken tire replaced. It would make sense to save costs there as much as you could without sacrificing safety and use the funds saved on something else.

If we applied the same idea to the hyperdrive it's possible that the back up hyperdrives had lesser quality components (not bad enough to cause a safety risk but not as robust as the better quality ones) and possibly not as efficient/robust design but then it was only meant to get to the closest spacedock for repairs not act as a replacement.