# Going to space with no engines **URL:** \ **Category:** Factual Questions\ **Created:** [April 25, 2014, 6:13pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976 "2014-04-25T18:13:00Z")\ **Posts on this page:** 14\ **Page:** 3
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [May 1, 2014, 8:07pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/41 "2014-05-01T20:07:52Z")
> [@Chronos](#): > > Note that, if you don’t have that pesky atmosphere to deal with, you can launch at any angle: Your accelerator can just be sitting on level ground and shoot horizontally. We only launch rockets vertically because the atmosphere is so problematic, that we want to get out of it as quickly as possible. Note that you still want to fire an insertion burn to round out your orbit at the higher altitude - otherwise you return where you started to graze the launcher (bet case) ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [May 1, 2014, 9:25pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/42 "2014-05-01T21:25:40Z")
> [@wolfpup](#): > > … in thinking it over, I see that you’re right. Even if you shot the projectile horizontally, it would go around one orbit and come back to hit you in the ass! Ignorance fought! Mine too. It’s pretty obvious in hindsight, but before being corrected on this point here at the Dope, I didn’t realize that if you do an instantaneous change in DeltaV, you change your orbit, but it still intersects the point where you made the change. This clarifies a lot of simplistic thinking about astrophysics (which come to think of it, is pretty dangerous unless it’s just a thought experiment. :o ) > [@Stranger on a Train](#): > > Luna makes a poor gravitational ‘slingshot’ to go to Mars because there are very few opportunities to launch directly from Earth and around the Moon that result in a trajectory that is directed in the plane of the solar ecliptic, owing to the fact that the Moon is inclined over five degrees from the ecliptic. (Technically, we’re more concerned about the invariable plane than the ecliptic, but the results are about the same; Thanks! Interesting. Also, thanks for introducing me to the invariable plane. > [@Chronos](#): > > Note that, if you don’t have that pesky atmosphere to deal with, you can launch at any angle: Your accelerator can just be sitting on level ground and shoot horizontally. Plus you get the added benefit that when you return, you’ll skid across the ground and bounce, rather than slam smack dead down into the ground, at whatever’s at the opposite side of the Earth at that time! ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [May 2, 2014, 3:31am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/43 "2014-05-02T03:31:26Z")
The US can try using a trampoline, according to the Russian Deputy PM: [https://twitter.com/DRogozin/statuses/461167801835991040](https://twitter.com/DRogozin/statuses/461167801835991040) (Huh, Russia allows Twitter? Their politicians even use it?) ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [May 2, 2014, 4:18am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/44 "2014-05-02T04:18:39Z")
> [@Learjeff](#): > > Thanks! Interesting. Also, thanks for introducing me to the invariable plane. Ditto. Now I realise that I have been misusing the term ecliptic. (Not that many would notice!) I thought that the ecliptic is the plane of the planets’ orbits (well, a weighted average.) Turns out this is closer to the definition of invariable plane. I had no idea that ecliptic was specifically referring to Earth’s orbital plane. Ignorance fought. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 2, 2014, 7:35am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/45 "2014-05-02T07:35:37Z")
Any way you can reach escape velocity will work. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 2, 2014, 7:42am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/46 "2014-05-02T07:42:22Z")
> [@j\_sum1](#): > > Ditto. Now I realise that I have been misusing the term ecliptic. (Not that many would notice!) I thought that the ecliptic is the plane of the planets’ orbits (well, a weighted average.) Turns out this is closer to the definition of invariable plane. I had no idea that ecliptic was specifically referring to Earth’s orbital plane. > > Ignorance fought. Technically, technically the ecliptic IS the sun’s annual apparent path across the sky relative to the background stars. Yes, we know the earth is really moving, but the ecliptic refers to the sun’s apparent motion. I make this distinction because it is no coincidence the word “eclipse” and “ecliptic” sound alike. There is more to these two words, but that is good enough for now. ---
**Author:** ![Miss\_Gnomer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miss_gnomer/32/3466_2.png) [@Miss\_Gnomer](https://boards.straightdope.com/u/Miss_Gnomer)\ **Post date:** [May 2, 2014, 9:30am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/47 "2014-05-02T09:30:38Z")
Soaring / gliding could get close? [http://www.perlanproject.org/](http://www.perlanproject.org/) Their promo is “soaring to the edge of space” ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [May 3, 2014, 3:25am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/48 "2014-05-03T03:25:05Z")
An idea of mine to at least supplement newtonian thrust. [http://boards.straightdope.com/sdmb/showthread.php?t=254792&highlight=launch](http://boards.straightdope.com/sdmb/showthread.php?t=254792&highlight=launch) ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [May 3, 2014, 4:22am UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/49 "2014-05-03T04:22:58Z")
> [@Miss\_Gnomer](#): > > Soaring / gliding could get close? [http://www.perlanproject.org/](http://www.perlanproject.org/) Their promo is “soaring to the edge of space” There’s a difference between soaring in an atmosphere, however tenuous, and reaching orbital speed - where you circle the globe, about 26,000 miles in 90 minutes. The traditional methods of acceleration usually involve reaction mass, and reaction mass to reach 18000mph is not trivial. Soaring, balloons, piggy back on a normal jet, whatever - these will serve the job of getting you outside most of the atmosphere and perhaps a boost of 500 to 1,000mph - but that’s a small fraction of orbital velocity. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [May 3, 2014, 9:32pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/50 "2014-05-03T21:32:45Z")
> [@md2000](#): > > Soaring, balloons, piggy back on a normal jet, whatever - these will serve the job of getting you outside most of the atmosphere and perhaps a boost of 500 to 1,000mph - but that’s a small fraction of orbital velocity. So how much savings would there be from not having to punch through most of the atmosphere on rocket power? ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [May 3, 2014, 11:18pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/51 "2014-05-03T23:18:44Z")
> [@Sunspace](#): > > So how much savings would there be from not having to punch through most of the atmosphere on rocket power? Here are some numbers you can work from: Felix Baumgartner jumper from a balloon at 127K’, so we should be able to assume a similar altitude could be reached for a stable launch. The first stage of the Saturn V weighed 2300 metric tons and burned for around two and a half minutes, accelerating from a rate of 13 m/s/s to 38 m/s/s to 6145 mph at 220K’. The first stage accounted for around three quarters of the rocket’s mass, so a large portion of its fuel was devoted to pushing the weight of its fuel upwards. Escape velocity from about where you are standing is a little over 25K mph. It will be somewhat lower at a hundred thousand feet. However, from an airborne platform, to launch upward, you basically have to use a rocket, because anything else has to push against the platform with its launching force (or fling a counterweight downward). ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 4, 2014, 10:56pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/52 "2014-05-04T22:56:20Z")
I’ve seen proposals for a combination of ballooning, soaring, and low-thrust, high-efficiency engines which, on paper, would bring launch costs down a few orders of magnitude. Of course, it’s always tough to say how seriously to take on-paper savings. ---
**Author:** ![PlainJain](https://avatars.discourse-cdn.com/v4/letter/p/5daacb/32.png) [@PlainJain](https://boards.straightdope.com/u/PlainJain)\ **Post date:** [May 4, 2014, 11:00pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/53 "2014-05-04T23:00:50Z")
I read the OP as going to space with no enemas… Carry on. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [May 5, 2014, 3:19pm UTC](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976/54 "2014-05-05T15:19:57Z")
Few other options provide comparable thrust. [Previous page](https://boards.straightdope.com/t/going-to-space-with-no-engines/686976.md?page=2)