Next-generation spaceplane: DARPA and Boeing to make on-demand space launches a reality by 2020s

DARPA has taken a major step towards the creation of a new class of hypersonic aircraft that would offer low-cost, short-notice space launches, with the selection of The Boeing Company as its design partner.

Having already developed initial designs for the next-generation spaceplane, known as Experimental Spaceplane or XS-1, Boeing will now be tasked with completing detailed working designs, fabricating the craft and performing flight tests. The vehicle will be constructed and tested by 2019, before embarking on between 12 and 15 test flights in 2020.

Once completed, the plane will represent a major step forward in accessing space, allowing launches to be enacted within a matter of days, rather than the current timescale of months or years, and at a cost far lower than is currently the case.

“The XS-1 would be neither a traditional airplane nor a conventional launch vehicle but rather a combination of the two, with the goal of lowering launch costs by a factor of ten and replacing today’s frustratingly long wait time with launch on demand,” said Jess Sponable, DARPA program manager.

Designed to be completely re-useable, the unmanned XS-1 is around the same size as a business jet, and would take off vertically like a traditional rocket.

However, unlike a traditional rocket, it would require no external boosters to launch, instead being powered entirely by self-contained cryogenic propellants. Once the XS-1 arrived in subortbit, a booster would release a one-use upper stage to deploy the payload: a satellite, before the craft itself returned to Earth, landing horizontally like an aircraft.

Upon landing, the craft would be prepped for the next launch, and would be available to blast off again within a matter of hours. It is hoped that it will cut the cost of launch to below $5m per launch with frequent flights.

“We’re delighted to see this truly futuristic capability coming closer to reality,” said Brad Tousley, director of DARPA’s Tactical Technology Office (TTO).

“Demonstration of aircraft-like, on-demand, and routine access to space is important for meeting critical Defense Department needs and could help open the door to a range of next-generation commercial opportunities.”

Images courtesy of DARPA

Now Boeing has been selected to move forward with the spaceplane, it will face a very short timeframe in which to complete a working craft.

“We’re very pleased with Boeing’s progress on the XS-1 through Phase 1 of the program and look forward to continuing our close collaboration in this newly funded progression to Phases 2 and 3—fabrication and flight,” said Sponable.

From now until 2019, Boeing will be tasked with completing all design work and fabricating the spaceplane, before completing on-the-ground tests. These will require the aircraft to be fired 10 times in 10 days before a launch is attempted.

Once this stage is completed, Phase 3 will be launched, which will see the spacecraft complete between 12 and 15 test flights in 2020.

After these, the XS-1 will be subject to more rigorous flight tests, including 10 flights in 10 days, first without payloads, at speeds up to Mach 5. Eventually the spaceplane will be tested at Mach 10, and will deliver dummy payloads first at a fraction of and then the full weight of a satellite.

A lunar station is the “next logical step in space development”

The next step for space development should be the creation of a lunar station, according to a paper published in the journal New Space. It is argued that the lessons learnt from the development of the International Space Station (ISS) should now be turned towards “exploring architectures for beyond low-earth-orbit (LEO) space development.”

Perhaps one of the chief arguments for a lunar station is its capability to act as a testing ground. In the same way that the decades-long development of the ISS taught us about technologies and science in LEO, the development of those capabilities into a lunar station could help enable the long-term aspiration to establish a settlement on Mars.

“It can provide a testing and proving ground for a variety of important advanced technologies and capabilities, including robotics, ISRU, resource depots, deep-space crew habitats, closed-loop life support, in-space propulsion, optical communication, and space-additive manufacturing,” the authors, Robert Bruce Pittman, Lynn D Harper, Mark E Newfield and Daniel J Rasky from NASA’s Space Portal, wrote in the paper.

A design for a lunar base by Foster + Partners developed for the European Space Agency. Image and featured image courtesy of ESA/Foster + Partners

The possibilities for scientific studies are also mentioned but, perhaps more interestingly, “the Lunar Station will give our space program a much-needed logical next step to strengthen its relevance to the US public, its leadership in the international community, and its technical cutting edge.” Fittingly given the Trump presidency’s approach to space being reminiscent of the space race, the lunar station is suggested as a means to re-establish the US as a forerunner in space development.

Furthermore, there is a clear emphasis on the potential offered by partnering with private space companies. The paper points out that both China and the European Space Agency (ESA) are not only planning for further lunar exploration and development, but have declared themselves open to collaboration with private companies.

With probably the foremost private space company in the world, SpaceX, based in the US, and President Trump favouring private companies taking part in future space development, it makes sense to leverage Elon Musk’s ambitions toward a more currently achievable goal than Mars. With the paper also finding interest from the investment community, a lunar station could well be a private-fronted effort.

A 1989 depiction of a lunar base, showing an expandable habitat module similar to the real-life modules developed by Bigelow Aerospace. Image courtesy of NASA

The station itself would be a permanent facility on the Moon, able to support crews of 6-10 people. Intended to operate and develop similarly to the ISS, but with a broader range of stakeholders, the station would act as both the hub and starting point for any further settlement of the Moon. In the same way that the ISS now features commercial activities in addition to the scientific work, the various stakeholders in the station would be able to develop their interests around the core of the station.

“The Lunar Station community would jointly develop and share infrastructure as well as separately develop and own specific capabilities,” the authors wrote. “Activities would range from scientific research and technology development to resource mining and processing and to human exploration of the Moon and even tourism.”

The paper predicts that it would take 5 years to build the station and it would cost roughly $2bn a year to build and operate.