US Military Seeks Nuclear Space Flight Test by 2025

The U.S. military has chosen three companies to develop nuclear thermal¹ propulsion, or NTP systems to be tested in space by 2025. The goal is to test the space travel technology in cislunar space – the area between Earth and the moon.

What is NTP?

The U.S. Department of Energy describes on its website how an NTP system works. It needs a radioactive material such as uranium and another element, such as hydrogen, in liquid form. The liquid propellant is pumped through a reactor² core. This causes uranium atoms to break apart inside the core and release heat. The heat turns the propellant into gas, which expands through an opening to produce thrust.

Scientists say NTP engines have far higher energy density³ and are twice as efficient as rocket engines.

The contracts to produce a flight demonstration⁴ of NTP technology were awarded by the military's Defense⁵ Advanced Research Projects Agency, or DARPA. The winning contractors⁶ were General Atomics, Blue Origin and Lockheed Martin. DARPA did not announce how much the contracts were worth.

In a recent announcement about the project, DARPA said the area of space, or "space domain⁷," will be very important to business, scientific discovery and national defense. Establishing "space domain awareness⁸ in cislunar space...will require a leap-ahead in propulsion technology," the agency said.

The agency added that one of the most important abilities of modern military operations is for forces to be able to react quickly to threats on land, at sea and in the air. However, doing this in space is difficult because current spacecraft designs lack the necessary speed and propellant power.

The project is called the Demonstration Rocket for Agile⁹ Cislunar Operations, or DRACO. It aims to have a rocket successfully demonstrate a working NTP system above low Earth orbit by 2025. The companies will be working to develop and demonstrate reactor, propulsion and spacecraft systems.

Air Force Major Nathan Greiner is the program manager for DRACO. "The NTP technology we seek to develop and demonstrate under the DRACO program aims to be foundational to future operations in space," he said in a statement.

DARPA said the first part of the demonstration process is to be carried out in two parts or "tracks." This process will last 18 months.

The first track will create a design for an NTP reactor and propulsion system. The second will produce an "operational system spacecraft concept" for demonstration purposes. The early development process will center on "risk reduction" efforts on the path to reaching the "on-orbit demonstration" by 2025, DARPA said.

NTP and NASA

The U.S. space agency NASA has long been interested in nuclear propulsion systems to power its spacecraft of the future. But the technology has not yet been demonstrated.

NASA has said that in recent years, its engineers have been considering NTP technology to support future missions to the moon and Mars. NASA is also considering a related technology, nuclear electric. That system uses propellants much more efficiently¹⁰ than chemical rockets, but provides a much lower amount of thrust compared to NTP.

NASA says it is working with the Department of Energy on the design and development efforts.

NASA said in a statement in February that its main goal with nuclear propulsion would be to greatly reduce the amount of time it takes crews to travel between Earth and Mars. With chemical propulsion, the trip to Mars would take about seven months. But with an NTP system, it could take three to four months. This would permit more trips, while improving the safety for astronauts in future space travel, NASA officials said.

Words in This Story

propulsion – n. a force that moves something forward

propellant – n. an explosive substance of fuel that causes something to move forward

thrust – n. upward push or force

core – n. the basic and most important part of something

efficient – adj. capable of producing the desired results without wasting time and energy

leap – adj. a big change, increase or improvement

concept – n. an idea of what something is or how it works

mission – n. the flight of a spacecraft to perform a task or job

1 thermal   

adj.热的，由热造成的；保暖的

参考例句：

• They will build another thermal power station.他们要另外建一座热能发电站。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

2 reactor   

n.反应器；反应堆

参考例句：

• The atomic reactor generates enormous amounts of thermal energy.原子反应堆发出大量的热能。
• Inside the reactor the large molecules are cracked into smaller molecules.在反应堆里，大分子裂变为小分子。

3 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。

4 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

5 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

6 contractors   

n.（建筑、监造中的）承包人( contractor的名词复数 )

参考例句：

• We got estimates from three different contractors before accepting the lowest. 我们得到3个承包商的报价后，接受了最低的报价。 来自《简明英汉词典》
• Contractors winning construction jobs had to kick back 2 per cent of the contract price to the mafia. 赢得建筑工作的承包商得抽出合同价格的百分之二的回扣给黑手党。 来自《简明英汉词典》

7 domain   

n.(活动等)领域，范围；领地，势力范围

参考例句：

• This information should be in the public domain.这一消息应该为公众所知。
• This question comes into the domain of philosophy.这一问题属于哲学范畴。

8 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

9 agile   

adj.敏捷的，灵活的

参考例句：

• She is such an agile dancer!她跳起舞来是那么灵巧！
• An acrobat has to be agile.杂技演员必须身手敏捷。

10 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。