Space Launch technology: are we stuck?

The majority of market players are creating copies of previous attempts and adding minor tweaks with no significant change in performance for space launch tech. Should we think bigger?

A few startups asked us for advice recently, as they had to pivot away from the space launch market due to a lack of investor interest. Admittedly, we were taken aback by this since the market is allegedly worth billions. This week, we decided to explore why investors are no longer so easily charmed by space launch technologies. Simply put, space launch tech today is anything that facilitates the transportation of payloads or humans from Earth to orbit. It would be equally relevant for Mars to orbit launches when we have a colony there too, or even star-to-star launches at some point. We do secretly hope that our blog will live long enough to witness the first intergalactic tours.

Photo by NASA on Unsplash

How high do we need to go?

Anything higher than 100km (Kármán line) above sea level is considered outer space. Outer space is further broken down into different orbit types based on various technologies and altitudes required to reach that orbit. For example, some tourist flights are designed for suborbital missions (when the object reaches the orbital altitude, but the speed is not high enough to complete the orbit and the object returns to Earth). Another example - an altitude of 2000km and below (can be as low as 160km) corresponds to  LEO (Low Earth Orbit). LEO contains most of the artificial objects in outer space and welcomed all crewed missions with the exception of the Apollo missions which went all the way to the Moon. There are also other orbits such as GEO (Geostationary Orbit, 35786 km), MEO (between GEO and LEO), heliocentric, interplanetary, and others. An object in GEO has an orbital period equal to Earth's rotational period. To ground observers, it appears motionless and in a fixed position in the sky. Most of the space launch technologies are targeting sub-orbital and LEO missions as this is sufficient for most of the current needs. Other technologies, like expendable upper rocket stages or prospective space tugs, are used to move satellites to higher orbits.

Image credit: University of Waikato

Space Launch physics: Jet propulsion

Out of 125 space launch companies, there are only 9 that have the functioning tech capable of reaching LEO, and their cumulative funding has reached $10B. The physics behind the mainstream approach to space launch is called ‘Jet propulsion’ which is commonly associated with aerospace pioneer Tsiolkovsky. Jet propulsion is the movement of the body due to ejection of matter (e.g., gas or a liquid) from the body. For effective jet propulsion you need to: 1) optimize the engine (including fuel)  2) optimize the weight and the shape of the body 3) optimize the process of production (3D printing, re-usability). Almost all 125 companies focus on producing incremental efficiency boosts rather than 0 to 1 breakthroughs. As always, there are exceptions. Within jet propulsion, we have two go-to options: rockets and spaceplanes. Conventional rockets still dominate the launch market with giant SpaceX operating 34% of all launches in 2022. We have decided to dedicate a separate piece solely to rockets but read on to learn more about spaceplanes. Please let us know if you would be interested to collaborate on the deep dive about rockets!

Photo by SpaceX on Unsplash

Medium class & the raise of spaceplanes

Current classifications for ‘medium’ launch vehicles are 2-20 tons of payload at LEO. Most funded companies in this segment are in the spaceplanes category. A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. All spaceplanes to date have been rocket-powered and landed as unpowered gliders. The spaceplane segment has a high potential for space tourism, a satellite launch, and intercontinental transportation. The industry is split about the spaceplane's future development and there are a lot of trial launches for 2023-2025 - we will find out who was right in the near future. A Japanese university start-up Space Walker attracted USD 5M to build one spaceplane which can be used as 3-in-1: to perform science missions, satellite launches, and space tourism. Canadian Space Engine Systems raised USD 22M and you can already reserve a seat for their suborbital flights in 2025. Of course, there is also Virgin Galactic, which is targeting the space tourism market and projected to grow to 1B by 2030.

Reclining seats for the journey to the edge of the Earth’s atmosphere, where passengers will experience weightlessness CREDIT: AFP

Heavy lifters

As of 2022, Saturn V, an American retired launch vehicle, on which people flew to the Moon remains the heaviest lifter rocket to date at 140 tons. Heavy rockets can carry 20-50 tons of payload, while the super heavy ones can handle payload weights over 50 tons. Around 20 private companies are competing in the field, 9 companies are VC-backed, 4 of which are working on spaceplanes. A notable example is Advanced Rockets Corp with their motto ‘Space should be routine’. The company is trying to combine two types of engines (one similar to what planes use to travel through the atmosphere and a rocket propulsion one). A promise made is to reduce the cost to deliver 1kg to LEO down to USD100 (15x less than today). SpaceX’s Starship is expected soon which is a hybrid between a spaceplane and rocket.

Space Launch physics: Alternatives

Multiple alternative technologies are being developed that can theoretically replace jet propulsion. Some VC-backed startups are working on “external energy rocket propulsion”: when there’s no fuel inside the rocket, and it is pushed from the outside (normally, on Earth’s surface) by a powerful force. For very small payloads (<200 kg), the pushing force can be exerted by a simple balloon, WaveMotion’s gas jet-gun, or SpinLaunch’s mass accelerator that catapults payloads into space like a slingshot. When it comes to larger payloads, a high-energy microwave or laser beam can be used to propel spacecraft to orbit. Spaceborne, for instance, uses the microwave approach for external energy rocket propulsion. Importantly, the Moon and Mars present a more favorable environment for the alternative launch methods because they have a less dense atmosphere and weaker gravity. There are also other options like orbit lift or railgun, but to the best of our knowledge there aren’t any notable projects just yet.

Image credit: Space Perspective

The development pace of launch technologies is quite slow and lacks 0 to 1 commercially viable innovations. There are a lot of projects that offer incremental increases in efficiency which is probably why investors are not rushing into this market. Moreover, launch technologies are incredibly capital intensive and require years (if not decades) of R&D, which makes it hard for new entrants to compete with the industry giants like SpaceX. Have we made much progress in the last 50 years? Should we think bigger? Can we support the brave? When will we discover new physics principles which will change the world? We are always happy to hear your feedback, answer your questions or just brainstorm new ideas together. Please do reach out by commenting or sending us an email.