What is Gateway Earth? What is it for? Where is it?
Gateway Earth will be a combined governmental space station and commercial space hotel, located in geostationary orbit (GEO). At this location it is close to the edge of Earth’s “gravity well”, and so it is a great place for interplanetary spacecraft to dock both as they depart for, and as they return from, distant solar system destinations. This would apply to both robotic and crewed missions. For the same reason it is a great place to assemble the interplanetary craft, which would then avoid the craft having to withstand the rigors of launch and re-entry through Earth’s atmosphere. Space tourism revenues will provide a significant part of the funding needed to both build the complex and supply the regular reusable tug service. Space tourists at the hotel will get a magnificent view of an entire hemisphere of the Earth. They, and the government astronauts, will get to and from the complex using a regular reusable shuttle taxi service.
What is a gravity well?
The planets and other massive objects in the solar system all exert a gravitational pull on each other depending on their size and distances apart. This pull is therefore strongest when very near the object. And for most of the large distances in between it is insignificant. Mathematically, this can be represented by a large flat “geopotential plateau” covering most of the solar system, with deep “wells” associated with the objects. Earth itself has its own “gravitational well” and spacecraft operating in or above geostationary orbit (GEO) are close to the “edge” of the well. From the edge of Earth’s “gravity well” an interplanetary spacecraft would therefore require very little energy to coast across the geopotential plateau to the region of any other solar system object, say Mars. However, to actually land on the distant object will require a means to descend into the distant object’s own “gravity well” – we usually refer to this means as the planetary approach and landing technology (usually some combination of retro rockets, parachutes, and a planetary lander vehicle).
How does it relate to the International Space Station (ISS)?
The ISS is located in Low Earth Orbit (LEO), and is therefore rather close to the Earth (only about 400 km). It is financed, owned and operated by a combination of international government space agencies. Its main purpose is for the conduct of experiments in conditions of zero-g related to science and engineering. It is mainly occupied by government astronauts who are there to represent their respective governments’ interests in exploring space. Access is via a government spacecraft launched on a governmental launcher (such as the Space Shuttle or Soyuz).
In contrast, the Gateway Earth complex is located in geostationary orbit (GEO) – which is about 36,000 km from Earth’s surface. It will be financed, owned and operated by a combination of commercial and governmental operators. Space tourists will regularly occupy the space hotel element of the complex. Access to and from Gateway Earth will be via a taxi ride provided by a commercial space tourism operator. Government astronauts at the Gateway Earth complex will not be there to conduct science; their role will instead be related to space exploration and the assembly of interplanetary vehicles heading onwards from Gateway Earth to other solar system destinations.
Why is is called a Gateway?
Gateway Earth will be the start and end point for astronauts taking journeys to celestial bodies beyond the Earth. It will be the last point from which they depart on their journey, and the first point they return to on their arrival home. They will receive a send-off from fellow astronauts, and also space tourists, at the complex when they head on outwards to the Moon, Mars or other destinations, and will receive a welcome there on their return from distant parts. They will get to and from Gateway Earth by using a regular routine “taxi service” of reusable tugs, which are also used by the space tourists. So it will be Gateway Earth from which the true exploration journeys depart.
What is the group GEDG trying to achieve?
We think this is a pretty neat solution for how we can continue to explore the solar system without it having to cost taxpayers more than they already have to spend. It brings space tourism revenues (and maybe revenues from other commercial space ventures) in to assist in supporting national space budgets. So, we want people to know that. And we want them to give serious consideration to this way forward. In the short term this is our focus. In the longer term, we intend to be the group which ensures that the governments and commercial operators continue talking to each other and do not take independent actions that would negatively impact the possibilities of this approach succeeding. We want to make sure, for instance, that there are common designs for use in both the government and commercial parts of the complex, and that the tugs may be used both by government astronauts and space tourists, and as cargo transports both up and down from GEO.
How real is it?
It is as real as we collectively can make it. At present, it does not form a part of any national space budget, or a part of any commercial space operators’ long range plans. We intend to change all that. And you can help us by joining in. You will be there at the start. Send an email to our interim secretary, Derek Webber, at DWspace@aol.com.
When is it going to happen?
The important first step is for a successful space tourism industry to develop and generate revenues. That will mean both sub-orbital trips (such as those soon to be offered by Blue Origin and Virgin Galactic) and orbital tourism (such as those already provided via Space Adventures using Soyuz, and potentially in a few years by SpaceX using Dragon). Given that, it may be 20 years before Gateway Earth is totally operating, but there can, and must, be significant activities between now and then to make it happen. Join us!
Is NASA supporting the idea?
Not at present. We have not yet knocked on their door. But we intend to change that, and have them including the Gateway Earth approach in their long range planning and budgeting.
How is it being funded?
At present, various elements of the concept are being developed independently by different space engineering firms; some large, and others small and entrepreneurial in nature. For example, one small firm called Made in Space, Inc. has already been testing 3-D manufacturing technologies in space. Another firm – Boeing – has been pursuing the approach to having orbital gas stations. Still another – Lockheed Martin – has been looking at reusable tugs. And several firms are having success at reusable launches from Earth to either above 100km on sub-orbital trajectories, or into Low Earth orbit (Blue Origin, SpaceX). Our aim is to synthesize all these disparate activities, and have them focus on making the overall Gateway Earth concept possible.
Which commercial firms are backing the idea?
At present, GEDG is new. We were just created in November 2015. We have not yet started spreading the word, but shall be expecting to announce various memorandums of understanding with commercial firms as we develop our materials and complete our analyses.
Why is the complex situated in the geostationary orbit (GEO)?
It needs to be near the edge of Earth’s gravity well, and if, furthermore, GEO is the chosen orbit, then there are several advantages:
Communications are simplified because the complex rotates at the same rate as the Earth, i.e., once a day, and it therefore appears to “hover” over a fixed location on the Earth, so terrestrial stations do not need to track a moving target.
Commercial revenue potential is maximized because many telecommunication satellites are in GEO, so there is an opportunity to base a commercial satellite service and refueling base at the Gateway Earth complex.
The space tourists at the Gateway Earth space hotel will have an amazing view that takes in almost an entire hemisphere of the Earth. The regular reusable tugs, traveling up and down between LEO and GEO, can be effectively financed by the space tourism business, but will provide a route for government astronauts to get to the complex.
How does a reusable tug operate?
Once it has been delivered into Low Earth Orbit (LEO), the tug needs to load up with its payload, which might be either cargo or government astronauts or space tourists. The cargo could be water, food, oxygen, and importantly the feedstock for the industrial scale 3-D manufacturing facility which is housed in the government part of the complex. Both the cargos and human occupants had previously been delivered to LEO via an Earth to LEO launch vehicle, which by the time of the operation of Gateway Earth will have become reusable. The International Space Station (ISS), or its successor, will continue to operate as a LEO node for the Gateway Earth system – and travelers may rendezvous and stay there for a short period before boarding the tug to take them onward and upward.
The tug then needs to refuel for its journey from LEO to GEO. It will do this in LEO by pulling in to a LEO gas station – which may be operated either by government or commercial operators. On arriving at the Gateway Earth complex. The tug needs to rendezvous and dock – with government astronauts up at the complex managing that process.
After it has been unloaded, it will return to LEO with its down-mass, including returning astronauts and space tourists.
So, the tug when operating never needs to pay attention to aeronautical drag or other related issues.
What will be the price for space tourists to go up to the GEO space hotel?
We believe that market research needs to be conducted to find out how much the very rich passengers would pay for, say, a two week stay at the GEO space hotel. However, we do know already that several space tourists have taken rides into Low Earth Orbit (LEO), costing from $20M to $50M, and so the question needing answering is how much more would they be willing to pay to go so very much higher? Folks always pay more to go faster or higher, or both 😉
What will it be like in the Gateway Earth space hotel?
There have already been prototype space hotels placed in orbit by the Las Vegas firm Bigelow Aerospace, and the main feature of their construction is that they are inflatable. We expect that there will be one astronaut “hotel manager” who looks after the safety and other logistics of the guest requirements. We are going to be looking at other aspects of the architectural design that will be expected by future space tourists. One set of requirements will certainly be a good set of optics so that the tourists can zoom in on any place on Earth that is visible to them. Obviously, one major attraction will be the zero-g environment – which might be a challenge for the hotel architects who are planning the shower or pool facilities.
What difference does it make for a tourist to be in Low Earth Orbit or GEO?
Everybody who has been into space (maybe 600 of them) has noted the changed perception it gives them. They see the curvature of the Earth; the black sky; they experience floating in zero-g, the thin atmosphere of Earth, and in general do not see the political boundaries that seem so important to the Earth-bound. But most of them never went higher than the ISS at 400 km. At Gateway Earth they will be almost 100 times higher. Just think of that. That is significant. If it would take 2 hours for a car traveling vertically upwards at 200km/hr to reach the ISS, then it would take the same car over a week to reach GEO. From that viewpoint one sees the whole orb of the Earth, not just a part of it. Only 24 men have so far seen that view, which they did en route to and from the Moon during the Apollo program nearly 50 years ago. Also, this space hotel is linked to a working space station where interplanetary craft are being manufactured and assembled. The space tourists will be there on hand to watch the work as it progresses. If they are lucky with their timing, they might even be there when an interplanetary craft is either leaving or returning. They might be amongst the first to greet the first astronauts to return from Mars!
What will government astronauts (NASA, etc.) do at Gateway Earth?
Gateway Earth becomes a new destination for government astronauts beyond Low Earth Orbit (LEO), somewhere they have not been since 1972, the time of the last Apollo mission. Their task there will not, however, be science. That can continue to be conducted at the ISS, and there are not many significant differences between LEO and GEO when it comes to the conduct of space science. However, they will be needed to operate this far outpost, the start and end point of interplanetary missions. They will be needed to ensure the safe arrivals and departures of the reusable tugs between LEO and GEO. And they will be needed to do the on-site engineering (often needing Extra Vehicular Activity – EVA’s) associated with the manufacture of parts from the onboard 3-D manufacturing facility, and their assembly into interplanetary spacecraft. And some of them will eventually board that spacecraft to head out on exploration missions.
What will be the eventual destination? Moon or Mars or elsewhere?
In principle, the physics of gravity wells makes it possible to consider any destination in the solar system. Or at least to the region near those objects outside of their local destination gravity wells. With additional investment it becomes possible to also have a landing stage as part of the interplanetary craft.
How come this will be so much cheaper?
This approach will be cheaper than alternative “traditional” ways to travel the solar system because almost all of the elements of the architecture will be reusable. Instead of throwing away all the parts of the Saturn V, which we did in 1969 as we proceeded to the Moon, this time the entire vehicle will be reusable. And the journey up and down to the Gateway Earth start and end point will also be totally reusable. Instead of needing to build many hundreds of spacecraft and launch vehicles, we shall only need a few. It will be the difference between building and buying a car every time you want to go somewhere then throwing it away, or buying a taxi ride. Also, the interplanetary craft themselves do not need to be built to withstand the buffeting of launch or the rigors of re-entry. Nor do they need much in the way of fuel, since they will be “coasting” across the interplanetary geopotential plateau between Gateway Earth and their destination. So they will be lighter, more flimsy and consequently cheaper. And of course cheaper still once they are re-used.
If this is so good, why has it not been done already?
Good question! The best answer is to say that all the elements have not been ready. In particular it will take time for the space tourism industry to get established both in sub-orbital and LEO destinations before the next destination, in GEO, can be entertained. And importantly, it has required a change in mindset in order to have governmental and commercial operators planning and working together toward a common goal. The GEDG has taken on that challenge. Come and join us!
How does Gateway Earth compare with NASA’s Deep Space Gateway concept?
NASA is considering having an international space station circling the Moon, known as the Deep Space Gateway (DSG). Like the Gateway Earth concept, the DSG will be situated in a place near to the edge of the interplanetary geopotential plateau, so can be a useful place to start and end missions. However, we believe that the Gateway Earth concept has advantages over the DSG approach. In particular, the DSG does not allow for the regular repeatable reusable tugs trips, which would be underwritten by the space tourism industry, when part of the Gateway Earth complex is a space tourism hotel. Furthermore, the communications would not be as simple with the DSG being behind the Moon for one hour out of every two hours. Thus, it would seem that Gateway Earth makes sense whether or not the DSG is introduced in orbit around the Moon.
Can I go?
No reason why not a priori. The Gateway Earth space hotel will be a commercial venture, and therefore the normal laws of supply and demand will apply. Anyone who can raise the ticket price will be able to add their name to the list of future tourists to the Gateway Earth complex.
Meanwhile, you can help make it all happen by following the GEDG developments, contributing ideas, and maybe even becoming a member of this working group, by contacting our Membership and Web Portal lead, Lawrence MacDonald at Lawrence.Macdonald@faa.gov.
If SpaceX is doing an interplanetary system, why do we need this?
In September, 2016, Elon Musk of SpaceX announced his plan for travelling to Mars for the purposes of colonization. He described an approach using fully reusable technology in very large vehicles designed to carry 200 passengers at a time to the Red Planet. So why do we need Gateway Earth? That is a very reasonable question, especially since SpaceX has been providing so much leadership and practical operational solutions for lower cost access to space. Firstly, we commend the vision and courage of Elon Musk, while perhaps questioning his ability to raise all of the required funds for his approach in the timescale he envisages. And we offer Gateway Earth as a complementary solution which will serve for smaller payloads, both crewed and robotic, destined to head for interplanetary destinations, and which will require far less resource since the Gateway Earth method is largely self-funding via space tourism revenues. We believe that Gateway Earth represents a more achievable target, especially with regards to “the next big step” for Space Agencies, such as NASA and ESA. We meanwhile encourage Musk’s further developments of reusability and in-orbit refueling technologies, both of which are essential elements of the Gateway Earth approach.