# Is it better to develop more powerful rockets instead of seeking and developing new technologies? [closed]

I have question about Space Industry and Era.

I'm aiming to being Rocket Scientist but I think it looks like will be so hard to reach far planets with these rocket technology that uses Newton's Laws and conservation of momentum. Filling up rocket's weight's 80%-90% with liquid hydrogen and liquid oxygene and a small percentage of payload I think, it would be hard and inefficient way to reach much more far planets or stars. If you think it's not right, please describe to me. I would be very happy.

Due to this situation, I think to involve Einstein's Unified Field Theory - General Relativity Theory and the bending of these theories with quantum field physics theories result of the efficient way to manage the whole universe's time and gravity. So this way, there will be a technology that doesn't obey 3rd dimension's rules (Newton's way). We can manage the 4th dimension (time, as Einstein's way).

I want to devote my life to develop a technology and new vision to these problems. Do you think this is a good and possible?

• There are middle ways -- technologies like ion engines, lightsails, mass drivers and various forms of nuclear rocket potentially offer travel around the solar system more quickly and conveniently than chemical fuelled rockets, without requiring completely new physics. May 4, 2019 at 17:30
• Conservation of momentum is a fundamental part of both quantum mechanics and relativity. May 4, 2019 at 18:10
• There's no reason to wait for new understandings of physics to come before we try exploring the solar system. Travel to the outer planets is within our physical understanding, if not our engineering. Have you heard of the [en.wikipedia.org/wiki/Alcubierre_drive](Alcubierre drive)? Something like that, if possible, would be what we want for travel been star systems. May 4, 2019 at 18:49
• Welcome to Space! Your question appears to be primarily opinion-based, and there may be no "correct" answer. I'm glad to hear of your enthusiasm; studying aeronautical engineering may help you to invent the next space technology! May 5, 2019 at 0:18
• @uhoh eh sure, why not. May 5, 2019 at 2:06

Refined from my general comment:

We don't need new physics knowledge to explore our solar system, whether the inner or outer planets. There's been considerable theoretical work on engines suitable for everything from Earth to orbit to Pluto and beyond. What you're referring to with most of a spacecraft's mass being propellant is the mass ratio: MR = (1 + lambda) / (epsilon + lambda), where epsilon is the mass of the structure divided by the mass of the structure with propellant, and lambda is the mass of the payload divided by the mass of the propellant and structure. The larger the mass ratio, the more payload you get for how much mass you're sending. So, how do we maximize the mass ratio? We choose engines with a high efficiency, or Isp (specific impulse). Basically, how effective an engine is at using its propellant. An engine such as a Hall effect thruster may have an Isp in the thousands of seconds, while an engine such as the Saturn V's F-1 has an Isp of about 304 seconds. The tradeoff there is that a Hall effect thruster has a pitiful thrust-weight ratio, and the F-1 has a high TWR. When it comes to intersystem travel, spacecraft have multiple factors to consider: launch vehicle, type of propellant, type of engine, destination, cost, availability of solar or nuclear power, and much more. In general, though, unmanned craft can afford long transit times with very efficient engines, while manned spacecraft should have a higher thrust to shorten transits.

Now, when it comes to interstellar travel, there are a number of interesting options. One is to take a large array of lasers, propel a lightsail to a significant fraction of the speed of light, and send it to another star system - with the proviso that unless it has onboard (and very powerful) engines, it will be unable to reverse acceleration in the target system and be captured by the star's gravity. Antimatter, if we could make it in sufficient quantities, would also enable interstellar travel in something less than a human lifetime. But if you want to go much, much faster, you would need something like the Alcubierre drive to make the trip, and the physics there is very theoretical indeed - we don't know how to make the exotic matter required, and that's one of the least of its issues. I don't see humans traveling to another solar system in this century as being probable, though certainly there will be humans among the outer planets once we build spacecraft such as argon-fueled nuclear electric ships.

You may find this table of engines useful and informative. The site itself is a gold mine of space-related information, so I hope it proves intriguing and helpful.

• I had a hunch you had more to say, but... wow!
– uhoh
May 5, 2019 at 2:59
• @uhoh Given the subjective manner of his question, I figured I should try to answer it in a way that would give him a basis for more objective future questions. May 5, 2019 at 3:43
• The problem is, what about if you don't just want to explore the solar system, but want to explore and travel around it in reasonable times, say under 30 Ms (~1 Earth year) to get to every destination including Pluto? That would seem to require still some considerable new improvements in propulsion technology, even if not interstellar-grade. E.g. just roughing by distance, with Pluto at ~6500 Gm and Mars at ~225 Gm that roughly entails a 1 megasecond transit to Mars as the ideal, maybe 2 if we let things be a bit less linear. Today's tech takes around 20. May 5, 2019 at 4:18
• Thus necessitating the development of technologies to reach speeds of around 150-300 km/s or so, which is stilll very much beyond the reach of chemical rockets. May 5, 2019 at 4:19
• ADD: Oops, just screwed that up - $t_c$ should be $1\ \mathrm{Ms}$, not 2... I used the total time and that $t_c$ is cruise time! Thus 300 km/s, 30 kN ... OUCH! May 5, 2019 at 4:36